<?xml version='1.0' encoding='utf-8'?><!-- Compiles with XML2RFC v3 https://xml2rfc.tools.ietf.org/cgi-bin/xml2rfc-dev.cgi --> <?rfc toc="yes"?> <?rfc tocompact="yes"?> <?rfc tocdepth="3"?> <?rfc tocindent="yes"?> <?rfc symrefs="yes"?> <?rfc sortrefs="yes"?> <?rfc comments="yes"?> <?rfc inline="yes"?> <?rfc compact="no"?> <?rfc subcompact="no"?> <?rfc authorship="yes"?> <?rfc tocappendix="yes"?><rfc xmlns:xi="http://www.w3.org/2001/XInclude" version="3" category="info" docName="draft-ietf-raw-architecture-30" number="9912" consensus="true" ipr="trust200902" updates="" tocInclude="true" obsoletes="" submissionType="IETF" xml:lang="en"version="3">sortRefs="true" symRefs="true" prepTime="2026-04-09T13:52:03" indexInclude="true" scripts="Common,Latin" tocDepth="3"> <link href="https://datatracker.ietf.org/doc/draft-ietf-raw-architecture-30" rel="prev"/> <link href="https://dx.doi.org/10.17487/rfc9912" rel="alternate"/> <link href="urn:issn:2070-1721" rel="alternate"/> <front> <title abbrev="RAW Architecture">Reliable and Available Wireless (RAW) Architecture</title> <seriesInfo name="RFC" value="9912" stream="IETF"/> <authorinitials='P' surname='Thubert' fullname='Pascal Thubert' role='editor'>initials="P" surname="Thubert" fullname="Pascal Thubert" role="editor"> <organizationabbrev=''>Without Affiliation</organization>showOnFrontPage="true">Independent</organization> <address> <postal> <city>Roquefort-les-Pins</city> <code>06330</code> <country>France</country> </postal> <email>pascal.thubert@gmail.com</email> </address> </author><date/> <area>Routing Area</area> <workgroup>DetNet</workgroup> <keyword>Draft</keyword> <abstract> <t><date month="04" year="2026"/> <area>RTG</area> <workgroup>detnet</workgroup> <keyword>DetNet</keyword> <abstract pn="section-abstract"> <t indent="0" pn="section-abstract-1"> Reliable and Available Wireless (RAW) extends the reliability and availability ofDetNetDeterministic Networking (DetNet) to networks composed of any combination of wired and wireless segments. The RAWArchitecturearchitecture leverages and extends RFC8655, the Deterministic8655 ("Deterministic NetworkingArchitecture,Architecture") to adapt to challenges thataffectprominently affect the wireless medium, notably intermittent transmission loss. This document defines a network control loop that optimizes the use of constrained bandwidth and energy whileassuringensuring the expected DetNet services. The loop involves a new Point of Local Repair (PLR) function in the DetNet Service sub-layer that dynamically selects the DetNet path(s) for packets to route around local connectivity degradation. </t> </abstract> <boilerplate> <section anchor="status-of-memo" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.1"> <name slugifiedName="name-status-of-this-memo">Status of This Memo</name> <t indent="0" pn="section-boilerplate.1-1"> This document is not an Internet Standards Track specification; it is published for informational purposes. </t> <t indent="0" pn="section-boilerplate.1-2"> This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are candidates for any level of Internet Standard; see Section 2 of RFC 7841. </t> <t indent="0" pn="section-boilerplate.1-3"> Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at <eref target="https://www.rfc-editor.org/info/rfc9912" brackets="none"/>. </t> </section> <section anchor="copyright" numbered="false" removeInRFC="false" toc="exclude" pn="section-boilerplate.2"> <name slugifiedName="name-copyright-notice">Copyright Notice</name> <t indent="0" pn="section-boilerplate.2-1"> Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. </t> <t indent="0" pn="section-boilerplate.2-2"> This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (<eref target="https://trustee.ietf.org/license-info" brackets="none"/>) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. </t> </section> </boilerplate> <toc> <section anchor="toc" numbered="false" removeInRFC="false" toc="exclude" pn="section-toc.1"> <name slugifiedName="name-table-of-contents">Table of Contents</name> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1"> <li pn="section-toc.1-1.1"> <t indent="0" keepWithNext="true" pn="section-toc.1-1.1.1"><xref derivedContent="1" format="counter" sectionFormat="of" target="section-1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-introduction">Introduction</xref></t> </li> <li pn="section-toc.1-1.2"> <t indent="0" keepWithNext="true" pn="section-toc.1-1.2.1"><xref derivedContent="2" format="counter" sectionFormat="of" target="section-2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-the-raw-problem">The RAW Problem</xref></t> </li> <li pn="section-toc.1-1.3"> <t indent="0" pn="section-toc.1-1.3.1"><xref derivedContent="3" format="counter" sectionFormat="of" target="section-3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-terminology">Terminology</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2"> <li pn="section-toc.1-1.3.2.1"> <t indent="0" keepWithNext="true" pn="section-toc.1-1.3.2.1.1"><xref derivedContent="3.1" format="counter" sectionFormat="of" target="section-3.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-abbreviations">Abbreviations</xref></t> </li> <li pn="section-toc.1-1.3.2.2"> <t indent="0" pn="section-toc.1-1.3.2.2.1"><xref derivedContent="3.2" format="counter" sectionFormat="of" target="section-3.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-link-and-direction">Link and Direction</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.2.2"> <li pn="section-toc.1-1.3.2.2.2.1"> <t indent="0" pn="section-toc.1-1.3.2.2.2.1.1"><xref derivedContent="3.2.1" format="counter" sectionFormat="of" target="section-3.2.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-flapping">Flapping</xref></t> </li> <li pn="section-toc.1-1.3.2.2.2.2"> <t indent="0" pn="section-toc.1-1.3.2.2.2.2.1"><xref derivedContent="3.2.2" format="counter" sectionFormat="of" target="section-3.2.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-uplink">Uplink</xref></t> </li> <li pn="section-toc.1-1.3.2.2.2.3"> <t indent="0" pn="section-toc.1-1.3.2.2.2.3.1"><xref derivedContent="3.2.3" format="counter" sectionFormat="of" target="section-3.2.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-downlink">Downlink</xref></t> </li> <li pn="section-toc.1-1.3.2.2.2.4"> <t indent="0" pn="section-toc.1-1.3.2.2.2.4.1"><xref derivedContent="3.2.4" format="counter" sectionFormat="of" target="section-3.2.4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-downstream">Downstream</xref></t> </li> <li pn="section-toc.1-1.3.2.2.2.5"> <t indent="0" pn="section-toc.1-1.3.2.2.2.5.1"><xref derivedContent="3.2.5" format="counter" sectionFormat="of" target="section-3.2.5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-upstream">Upstream</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.3.2.3"> <t indent="0" pn="section-toc.1-1.3.2.3.1"><xref derivedContent="3.3" format="counter" sectionFormat="of" target="section-3.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-path-and-recovery-graphs">Path and Recovery Graphs</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.3.2"> <li pn="section-toc.1-1.3.2.3.2.1"> <t indent="0" pn="section-toc.1-1.3.2.3.2.1.1"><xref derivedContent="3.3.1" format="counter" sectionFormat="of" target="section-3.3.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-path">Path</xref></t> </li> <li pn="section-toc.1-1.3.2.3.2.2"> <t indent="0" pn="section-toc.1-1.3.2.3.2.2.1"><xref derivedContent="3.3.2" format="counter" sectionFormat="of" target="section-3.3.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-recovery-graph">Recovery Graph</xref></t> </li> <li pn="section-toc.1-1.3.2.3.2.3"> <t indent="0" pn="section-toc.1-1.3.2.3.2.3.1"><xref derivedContent="3.3.3" format="counter" sectionFormat="of" target="section-3.3.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-forward-and-crossing">Forward and Crossing</xref></t> </li> <li pn="section-toc.1-1.3.2.3.2.4"> <t indent="0" pn="section-toc.1-1.3.2.3.2.4.1"><xref derivedContent="3.3.4" format="counter" sectionFormat="of" target="section-3.3.4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-protection-path">Protection Path</xref></t> </li> <li pn="section-toc.1-1.3.2.3.2.5"> <t indent="0" pn="section-toc.1-1.3.2.3.2.5.1"><xref derivedContent="3.3.5" format="counter" sectionFormat="of" target="section-3.3.5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-segment">Segment</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.3.2.4"> <t indent="0" pn="section-toc.1-1.3.2.4.1"><xref derivedContent="3.4" format="counter" sectionFormat="of" target="section-3.4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-deterministic-networking">Deterministic Networking</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.4.2"> <li pn="section-toc.1-1.3.2.4.2.1"> <t indent="0" pn="section-toc.1-1.3.2.4.2.1.1"><xref derivedContent="3.4.1" format="counter" sectionFormat="of" target="section-3.4.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-the-detnet-planes">The DetNet Planes</xref></t> </li> <li pn="section-toc.1-1.3.2.4.2.2"> <t indent="0" pn="section-toc.1-1.3.2.4.2.2.1"><xref derivedContent="3.4.2" format="counter" sectionFormat="of" target="section-3.4.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-flow">Flow</xref></t> </li> <li pn="section-toc.1-1.3.2.4.2.3"> <t indent="0" pn="section-toc.1-1.3.2.4.2.3.1"><xref derivedContent="3.4.3" format="counter" sectionFormat="of" target="section-3.4.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-residence-time">Residence Time</xref></t> </li> <li pn="section-toc.1-1.3.2.4.2.4"> <t indent="0" pn="section-toc.1-1.3.2.4.2.4.1"><xref derivedContent="3.4.4" format="counter" sectionFormat="of" target="section-3.4.4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-l3-deterministic-flow-ident">L3 Deterministic Flow Identifier </xref></t> </li> <li pn="section-toc.1-1.3.2.4.2.5"> <t indent="0" pn="section-toc.1-1.3.2.4.2.5.1"><xref derivedContent="3.4.5" format="counter" sectionFormat="of" target="section-3.4.5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-time-sensitive-networking">Time-Sensitive Networking</xref></t> </li> <li pn="section-toc.1-1.3.2.4.2.6"> <t indent="0" pn="section-toc.1-1.3.2.4.2.6.1"><xref derivedContent="3.4.6" format="counter" sectionFormat="of" target="section-3.4.6"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-lower-layer-api">Lower-Layer API</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.3.2.5"> <t indent="0" pn="section-toc.1-1.3.2.5.1"><xref derivedContent="3.5" format="counter" sectionFormat="of" target="section-3.5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-reliability-and-availabilit">Reliability and Availability</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.3.2.5.2"> <li pn="section-toc.1-1.3.2.5.2.1"> <t indent="0" pn="section-toc.1-1.3.2.5.2.1.1"><xref derivedContent="3.5.1" format="counter" sectionFormat="of" target="section-3.5.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-service-level-agreement">Service Level Agreement</xref></t> </li> <li pn="section-toc.1-1.3.2.5.2.2"> <t indent="0" pn="section-toc.1-1.3.2.5.2.2.1"><xref derivedContent="3.5.2" format="counter" sectionFormat="of" target="section-3.5.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-service-level-objective">Service Level Objective</xref></t> </li> <li pn="section-toc.1-1.3.2.5.2.3"> <t indent="0" pn="section-toc.1-1.3.2.5.2.3.1"><xref derivedContent="3.5.3" format="counter" sectionFormat="of" target="section-3.5.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-service-level-indicator">Service Level Indicator</xref></t> </li> <li pn="section-toc.1-1.3.2.5.2.4"> <t indent="0" pn="section-toc.1-1.3.2.5.2.4.1"><xref derivedContent="3.5.4" format="counter" sectionFormat="of" target="section-3.5.4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-precision-availability-metr">Precision Availability Metrics</xref></t> </li> <li pn="section-toc.1-1.3.2.5.2.5"> <t indent="0" pn="section-toc.1-1.3.2.5.2.5.1"><xref derivedContent="3.5.5" format="counter" sectionFormat="of" target="section-3.5.5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-reliability">Reliability</xref></t> </li> <li pn="section-toc.1-1.3.2.5.2.6"> <t indent="0" pn="section-toc.1-1.3.2.5.2.6.1"><xref derivedContent="3.5.6" format="counter" sectionFormat="of" target="section-3.5.6"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-availability">Availability</xref></t> </li> </ul> </li> </ul> </li> <li pn="section-toc.1-1.4"> <t indent="0" pn="section-toc.1-1.4.1"><xref derivedContent="4" format="counter" sectionFormat="of" target="section-4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-reliable-and-available-wire">Reliable and Available Wireless</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.4.2"> <li pn="section-toc.1-1.4.2.1"> <t indent="0" pn="section-toc.1-1.4.2.1.1"><xref derivedContent="4.1" format="counter" sectionFormat="of" target="section-4.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-high-availability-engineeri">High Availability Engineering Principles</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.4.2.1.2"> <li pn="section-toc.1-1.4.2.1.2.1"> <t indent="0" pn="section-toc.1-1.4.2.1.2.1.1"><xref derivedContent="4.1.1" format="counter" sectionFormat="of" target="section-4.1.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-elimination-of-single-point">Elimination of Single Points of Failure</xref></t> </li> <li pn="section-toc.1-1.4.2.1.2.2"> <t indent="0" pn="section-toc.1-1.4.2.1.2.2.1"><xref derivedContent="4.1.2" format="counter" sectionFormat="of" target="section-4.1.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-reliable-crossover">Reliable Crossover</xref></t> </li> <li pn="section-toc.1-1.4.2.1.2.3"> <t indent="0" pn="section-toc.1-1.4.2.1.2.3.1"><xref derivedContent="4.1.3" format="counter" sectionFormat="of" target="section-4.1.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-prompt-notification-of-fail">Prompt Notification of Failures</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.4.2.2"> <t indent="0" pn="section-toc.1-1.4.2.2.1"><xref derivedContent="4.2" format="counter" sectionFormat="of" target="section-4.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-applying-reliability-concep">Applying Reliability Concepts to Networking</xref></t> </li> <li pn="section-toc.1-1.4.2.3"> <t indent="0" pn="section-toc.1-1.4.2.3.1"><xref derivedContent="4.3" format="counter" sectionFormat="of" target="section-4.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-wireless-effects-affecting-">Wireless Effects Affecting Reliability</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.5"> <t indent="0" pn="section-toc.1-1.5.1"><xref derivedContent="5" format="counter" sectionFormat="of" target="section-5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-the-raw-conceptual-model">The RAW Conceptual Model</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.5.2"> <li pn="section-toc.1-1.5.2.1"> <t indent="0" pn="section-toc.1-1.5.2.1.1"><xref derivedContent="5.1" format="counter" sectionFormat="of" target="section-5.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-the-raw-planes">The RAW Planes</xref></t> </li> <li pn="section-toc.1-1.5.2.2"> <t indent="0" pn="section-toc.1-1.5.2.2.1"><xref derivedContent="5.2" format="counter" sectionFormat="of" target="section-5.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-raw-versus-upper-and-lower-">RAW Versus Upper and Lower Layers</xref></t> </li> <li pn="section-toc.1-1.5.2.3"> <t indent="0" pn="section-toc.1-1.5.2.3.1"><xref derivedContent="5.3" format="counter" sectionFormat="of" target="section-5.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-raw-and-detnet">RAW and DetNet</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.6"> <t indent="0" pn="section-toc.1-1.6.1"><xref derivedContent="6" format="counter" sectionFormat="of" target="section-6"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-the-raw-control-loop">The RAW Control Loop</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.6.2"> <li pn="section-toc.1-1.6.2.1"> <t indent="0" pn="section-toc.1-1.6.2.1.1"><xref derivedContent="6.1" format="counter" sectionFormat="of" target="section-6.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-routing-timescale-versus-fo">Routing Timescale Versus Forwarding Timescale</xref></t> </li> <li pn="section-toc.1-1.6.2.2"> <t indent="0" pn="section-toc.1-1.6.2.2.1"><xref derivedContent="6.2" format="counter" sectionFormat="of" target="section-6.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-ooda-loop">OODA Loop</xref></t> </li> <li pn="section-toc.1-1.6.2.3"> <t indent="0" pn="section-toc.1-1.6.2.3.1"><xref derivedContent="6.3" format="counter" sectionFormat="of" target="section-6.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-observe-raw-oam">Observe: RAW OAM </xref></t> </li> <li pn="section-toc.1-1.6.2.4"> <t indent="0" pn="section-toc.1-1.6.2.4.1"><xref derivedContent="6.4" format="counter" sectionFormat="of" target="section-6.4"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-orient-the-raw-extended-det">Orient: The RAW-Extended DetNet Operational Plane</xref></t> </li> <li pn="section-toc.1-1.6.2.5"> <t indent="0" pn="section-toc.1-1.6.2.5.1"><xref derivedContent="6.5" format="counter" sectionFormat="of" target="section-6.5"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-decide-the-point-of-local-r">Decide: The Point of Local Repair</xref></t> </li> <li pn="section-toc.1-1.6.2.6"> <t indent="0" pn="section-toc.1-1.6.2.6.1"><xref derivedContent="6.6" format="counter" sectionFormat="of" target="section-6.6"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-act-detnet-path-selection-a">Act: DetNet Path Selection and Reliability Functions</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.7"> <t indent="0" pn="section-toc.1-1.7.1"><xref derivedContent="7" format="counter" sectionFormat="of" target="section-7"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-security-considerations">Security Considerations</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.7.2"> <li pn="section-toc.1-1.7.2.1"> <t indent="0" pn="section-toc.1-1.7.2.1.1"><xref derivedContent="7.1" format="counter" sectionFormat="of" target="section-7.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-collocated-denial-of-servic">Collocated Denial-of-Service Attacks</xref></t> </li> <li pn="section-toc.1-1.7.2.2"> <t indent="0" pn="section-toc.1-1.7.2.2.1"><xref derivedContent="7.2" format="counter" sectionFormat="of" target="section-7.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-layer-2-encryption">Layer 2 Encryption</xref></t> </li> <li pn="section-toc.1-1.7.2.3"> <t indent="0" pn="section-toc.1-1.7.2.3.1"><xref derivedContent="7.3" format="counter" sectionFormat="of" target="section-7.3"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-forced-access">Forced Access</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.8"> <t indent="0" pn="section-toc.1-1.8.1"><xref derivedContent="8" format="counter" sectionFormat="of" target="section-8"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-iana-considerations">IANA Considerations</xref></t> </li> <li pn="section-toc.1-1.9"> <t indent="0" pn="section-toc.1-1.9.1"><xref derivedContent="9" format="counter" sectionFormat="of" target="section-9"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-references">References</xref></t> <ul bare="true" empty="true" indent="2" spacing="compact" pn="section-toc.1-1.9.2"> <li pn="section-toc.1-1.9.2.1"> <t indent="0" pn="section-toc.1-1.9.2.1.1"><xref derivedContent="9.1" format="counter" sectionFormat="of" target="section-9.1"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-normative-references">Normative References</xref></t> </li> <li pn="section-toc.1-1.9.2.2"> <t indent="0" pn="section-toc.1-1.9.2.2.1"><xref derivedContent="9.2" format="counter" sectionFormat="of" target="section-9.2"/>. <xref derivedContent="" format="title" sectionFormat="of" target="name-informative-references">Informative References</xref></t> </li> </ul> </li> <li pn="section-toc.1-1.10"> <t indent="0" pn="section-toc.1-1.10.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.a"/><xref derivedContent="" format="title" sectionFormat="of" target="name-acknowledgments">Acknowledgments</xref></t> </li> <li pn="section-toc.1-1.11"> <t indent="0" pn="section-toc.1-1.11.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.b"/><xref derivedContent="" format="title" sectionFormat="of" target="name-contributors">Contributors</xref></t> </li> <li pn="section-toc.1-1.12"> <t indent="0" pn="section-toc.1-1.12.1"><xref derivedContent="" format="none" sectionFormat="of" target="section-appendix.c"/><xref derivedContent="" format="title" sectionFormat="of" target="name-authors-address">Author's Address</xref></t> </li> </ul> </section> </toc> </front> <middle> <section numbered="true"toc="default"> <name>Introduction</name> <t>toc="include" removeInRFC="false" pn="section-1"> <name slugifiedName="name-introduction">Introduction</name> <t indent="0" pn="section-1-1"> Deterministic Networking (DetNet) aimsat providingto provide bounded latency andeliminatingeliminate congestion loss, even whenco-existingcoexisting with best-effort traffic. It provides the ability to carry specified unicast or multicast data flows for real-time applications with extremely low packet loss rates andassuredensures maximum end-to-end delivery latency. A description of the general background and concepts of DetNet can be found in[RFC8655]. </t> <t><xref target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/>. </t> <t indent="0" pn="section-1-2"> DetNet and the related IEEE 802.1 Time-SensitivenetworkingNetworking (TSN) <xreftarget="TSN"/>target="TSN" format="default" sectionFormat="of" derivedContent="TSN"/> initially focused on wired infrastructure, which provides a more stable communication channel than wireless networks. Wireless networks operate on a shared medium where uncontrolled interference, includingtheself-induced multipath fading, may cause intermittent transmission losses. Fixed and mobile obstacles and reflectors may block or alter the signal, causing transient and unpredictable variations of the throughput andpacket delivery ratioPacket Delivery Ratio (PDR) of a wireless link. This adds new dimensions to the statistical effects that affect the quality and reliability of the link. </t><t><t indent="0" pn="section-1-3"> Nevertheless, deterministic capabilities are required in a number of wireless use cases as well <xreftarget="I-D.ietf-raw-use-cases"/>.target="RFC9450" format="default" sectionFormat="of" derivedContent="RAW-USE-CASES"/>. With scheduled radios such asTime SlottedTime-Slotted Channel Hopping (TSCH) and OrthogonalFrequency DivisionFrequency-Division Multiple Access (OFDMA)(see <xref target="I-D.ietf-raw-technologies"/> for more on both of these and other technologies as well)being developed to provide determinism over wireless links at the lower layers, providing DetNet capabilities has become possible. See <xref target="RFC9913" format="default" sectionFormat="of" derivedContent="RAW-TECHNOS"/> for more on TSCH, OFDMA, and other technologies. </t><t><t indent="0" pn="section-1-4"> Reliable and Available Wireless (RAW) takes up the challenge of providing highly available and reliable end-to-end performances in a DetNet network that may include wireless segments. To achieve this, RAW leverages allthepossible transmission diversity and redundancy toassureensure packet delivery, while optimizing the use of the shared spectrum to preserve bandwidth and save energy. To that effect, RAW definesProtection Pathsprotection paths that can be activated dynamically upon failures and a control loop that dynamically controls the activation and deactivation of the feasibleProtection Pathsprotection paths to react quickly to intermittent losses. </t><t><t indent="0" pn="section-1-5"> The intent of RAW is to meet Service Level Objectives(SLO)(SLOs) in terms ofpacket delivery ratio (PDR),PDR, maximum contiguouslosseslosses, or latency boundaries for DetNet flows over mixes of wired and wireless networks, including wireless access and meshes (see <xreftarget="problem"/>target="problem" format="default" sectionFormat="of" derivedContent="Section 2"/> for more on the RAW problem). This document introduces and/or leverages terminology (see <xreftarget="terms"/>),target="terms" format="default" sectionFormat="of" derivedContent="Section 3"/>), principles (see <xreftarget="raw"/>),target="raw" format="default" sectionFormat="of" derivedContent="Section 4"/>), and concepts such as protectionpathpaths and recoverygraph,graphs to put together a conceptual model for RAW (see <xreftarget="model"/>), and, basedtarget="model" format="default" sectionFormat="of" derivedContent="Section 5"/>). Based on that model,elaboratethis document elaborates on an in-network optimization control loop (see <xreftarget="control"/>).target="control" format="default" sectionFormat="of" derivedContent="Section 6"/>). </t> </section><!-- Introduction --> <!-- 000000000000000000000 --><section anchor="problem" numbered="true"toc="default"> <name>The RAW problem</name> <t>toc="include" removeInRFC="false" pn="section-2"> <name slugifiedName="name-the-raw-problem">The RAW Problem</name> <t indent="0" pn="section-2-1"> While the generic<xref target="RFC8557">"Deterministic"Deterministic Networking ProblemStatement"</xref>Statement" <xref target="RFC8557" format="default" sectionFormat="of" derivedContent="RFC8557"/> applies to boththewired andthewireless media, the<xref target="RFC8655">"Deterministic"Deterministic Networking Architecture"</xref><xref target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/> must be extended to address less consistent transmissions, energy conservation, and shared spectrum efficiency. </t><t><t indent="0" pn="section-2-2"> Operating atLayer-3,Layer 3, RAW does not change the wireless technology at the lower layers.OTOH,On the other hand, it can further increase diversity in the spatial, time, code, and frequency domains by enabling multiple link-layer wired and wireless technologies in parallel or sequentially, for a higher resilience and a wider applicability. RAW can also provide homogeneous services to critical applications beyond the boundaries of a single subnetwork, e.g., using diverse radio access technologies to optimize the end-to-end application experience. </t><t><t indent="0" pn="section-2-3"> RAW extends the DetNet services by providing elements that are specialized for transporting IP flows over deterministic radio technologies such as those listed in <xreftarget="I-D.ietf-raw-technologies"/>.target="RFC9913" format="default" sectionFormat="of" derivedContent="RAW-TECHNOS"/>. Conceptually, RAW is agnostic to the lower layer, though the capability to control latency is assumed toassureensure the DetNet services that RAW extends. How the lower layers are operated to doso, and, e.g.,so (and whether a radio network issingle-hopsingle hop or meshed, for example) are opaque to the IP layer and not part of the RAW abstraction. Nevertheless, cross-layer optimizations may take place to ensure proper link awareness(think,(such as link quality) and packet handling(think,(such as scheduling). </t><t><t indent="0" pn="section-2-4"> The RAWArchitecturearchitecture extends the DetNet NetworkPlane,Plane to accommodate one or multiple hops of homogeneous or heterogeneous wired and wireless technologies. RAW adds reactivity to the DetNetForwardingforwarding sub-layer to compensate the dynamics for the radio links in terms of lossiness and bandwidth. This may apply, for instance, to mesh networks as illustrated in <xreftarget ="FigCPF"/>,target="FigCPF" format="default" sectionFormat="of" derivedContent="Figure 4"/> or diverse radio access networks as illustrated in <xreftarget ="Figranp2"/>. </t> <t>target="Figranp2" format="default" sectionFormat="of" derivedContent="Figure 10"/>. </t> <t indent="0" pn="section-2-5"> As opposed to wired links, the availability and performance of an individual wireless link cannot be trusted over the long term; it varies with transient service discontinuity, and any path that includes wireless hops is bound to face short periods of high loss. On the other hand, being broadcast in nature, the wireless medium provides capabilities that are atypical on modern wired links and that the RAWArchitecturearchitecture can leverage opportunistically to improve the end-to-end reliability over a collection of paths. </t><t><t indent="0" pn="section-2-6"> Those capabilities include: </t><dl> <dt>Promiscuous Overhearing:</dt><dd><dl indent="3" newline="false" spacing="normal" pn="section-2-7"> <dt pn="section-2-7.1">Promiscuous overhearing:</dt> <dd pn="section-2-7.2"> Some wired and wireless technologies allow for multiple lower-layer attached nodes to receive the same packet sent by another node. This differs from a lower-layer network that is physicallypoint-to-pointpoint-to-point, like a wire. With overhearing, more than one node in the forward direction of the packet may hear or overhear a transmission, and the reception by one may compensate the loss by another. The concept of path can be revisited in favor ofmultipoint to multipointmultipoint-to-multipoint progress in the forward direction and statistical chances of successful reception of any of the transmissions by any of the receivers. </dd><dt>L2-aware routing:</dt><dd> As<dt pn="section-2-7.3">L2-aware routing:</dt> <dd pn="section-2-7.4"> <t indent="0" pn="section-2-7.4.1">As the quality and speed of a link varies over time, the concept of metric must also be revisited. Shortest-path cost loses its absolute value, and hop count turns into a bad idea as the link budget drops with the physical distance. Routing over radio requiresboth 1) aboth:</t> <ol indent="adaptive" spacing="normal" start="1" type="1" pn="section-2-7.4.2"> <li pn="section-2-7.4.2.1" derivedCounter="1.">a new and more dynamic sense of link metrics, with new protocols such asDLEPthe Dynamic Link Exchange Protocol (DLEP) andL2-triggerLayer 2 (L2) triggers to keepL3Layer 3 (L3) up to date with the link quality and availability,and 2) anand</li> <li pn="section-2-7.4.2.2" derivedCounter="2.">an approach to multipath routing, where multiple link metrics are considered since simple shortest-path cost loses its meaning with the instability of themetrics.metrics.</li> </ol> </dd><dt>Redundant transmissions:</dt><dd>Though<dt pn="section-2-7.5">Redundant transmissions:</dt> <dd pn="section-2-7.6">Though feasible on any technology, proactive (forward) and reactive(ack-based)(acknowledgment-based) error correctionareis typicalto thefor wireless media. Bounded latency can still be obtained on a wireless link while operating those technologies, provided that link latency used in path selection allows for the extratransmission,transmission orthatthe introduced delay is compensated along the path. In the case of coded fragments and retries, it makes sense to vary all the possible physical properties of the transmission to reduce the chances that the same effect causes the loss of both original and redundant transmissions. </dd><dt>Relay Coordination<dt pn="section-2-7.7">Relay coordination and constructiveinterference:</dt><dd>Thoughinterference:</dt> <dd pn="section-2-7.8">Though it can be difficult to achieve at high speed, a fine time synchronization and a precise sense of phase allows the energy from multiple coordinated senders to add up at the receiver and actually improve the signal quality, compensating for either distance or physical objects in the Fresnel zone that would reduce the link budget. From a DetNet perspective, this may translate to taking into account how transmission from one node may interfere with the transmission of another node attached to the same wireless sub-layernetwork. </dd>network.</dd> </dl><t><t indent="0" pn="section-2-8"> RAW and DetNet enable application flows that require a special treatment along paths that can provide that treatment. This may be seen as a form of Path AwareNetworkingnetworking and may be subject to impediments documented in <xreftarget="RFC9049"/>. </t> <t>target="RFC9049" format="default" sectionFormat="of" derivedContent="RFC9049"/>. </t> <t indent="0" pn="section-2-9"> Themechanismsmechanism used to establish a path is not unique to, or necessarily impacted by, RAW.ItThe mechanism is expected to be the product of the DetNet Controller Plane <xreftarget="I-D.ietf-detnet-controller-plane-framework"/>, andtarget="RFC9938" format="default" sectionFormat="of" derivedContent="DetNet-PLANE"/>; it may use a PathcomputationComputation Element (PCE) <xreftarget="RFC4655"/>target="RFC4655" format="default" sectionFormat="of" derivedContent="RFC4655"/> or the DetNetYang Data ModelYANG data model <xreftarget="RFC9633"/>,target="RFC9633" format="default" sectionFormat="of" derivedContent="RFC9633"/>, or it may be computed in a distributed fashionalaas per the Resource ReSerVation Protocol (RSVP) <xreftarget="RFC2205"/>.target="RFC2205" format="default" sectionFormat="of" derivedContent="RFC2205"/>. Either way, the assumption is that it is slow relative to local forwarding operations along the path. To react fast enough to transient changes in the radio transmissions, RAW leverages DetNet Network Plane enhancements to optimize the use of the paths and match the quality of the transmissions over time. </t><t><t indent="0" pn="section-2-10"> As opposed to wired networks, the action of installing a path over a set of wireless links may be very slow relative to the speed at which the radio conditionsvary, and it makes sensevary; thus, in the wirelesscasecase, it makes sense to provide redundant forwarding solutions alongaalternate paths (see <xreftarget="pt"/>)target="pt" format="default" sectionFormat="of" derivedContent="Section 3.3"/>) and to leave it to the Network Plane to select which of those forwarding solutions are to be used for a given packet based on the current conditions. The RAW Network Plane operations happen within the scope of a recovery graph (see <xreftarget="trk"/>)target="trk" format="default" sectionFormat="of" derivedContent="Section 3.3.2"/>) that is pre-established and installed by means outside of the scope of RAW. A recovery graph may be strict or loose depending on whether each hop or just a subset of the hopsareis observed and controlled by RAW. </t><t><t indent="0" pn="section-2-11"> RAW distinguishes the longertime-scaletimescale at which routes are computed from the shortertime-scaletimescale where forwarding decisions are made (see <xreftarget= "timescale"/>).target="timescale" format="default" sectionFormat="of" derivedContent="Section 6.1"/>). The RAW Network Plane operations happen at atime-scaletimescale that sits timewise between the routing and the forwardingtime-scales. Their goal is to select dynamically, withintimescales. Within the resources delineated by a recovery graph, their goal is to dynamically select the protection path(s) that the upcoming packets of a DetNet flow shall follow. As they influence the path forentirethe entirety of the flows or a portion offlows,them, the RAW Network Plane operations may affect the metrics used in their reroutingdecision,decisions, which could potentially lead to oscillations; such effects must be avoided or dampened. </t> </section><!-- The RAW problem --><section anchor="terms" numbered="true"toc="default"> <name>Terminology</name> <t>RAWtoc="include" removeInRFC="false" pn="section-3"> <name slugifiedName="name-terminology">Terminology</name> <t indent="0" pn="section-3-1">RAW reuses terminology defined for DetNet inthe <xref target="RFC8655">"Deterministic NetworkingArchitecture"</xref>,Architecture" <xref target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/>, e.g.,PREOF"PREOF" to stand forPacket"Packet Replication,EliminationElimination, and OrderingFunctions.Functions". RAW inherits and augmentstheIETFart of Protectionrecovery mechanisms such asseenthe ones provided in DetNet <xref target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/> and in TrafficEngineering. </t> <t>RAWEngineering, e.g., <xref target="RFC4090" format="default" sectionFormat="of" derivedContent="RFC4090"/>. </t> <t indent="0" pn="section-3-2">RAW also reuses terminology defined for Operations, Administration, and Maintenance (OAM) protocols in Section1.1 of the<xreftarget="RFC9551">target="RFC9551" sectionFormat="bare" section="1.1" format="default" derivedLink="https://rfc-editor.org/rfc/rfc9551#section-1.1" derivedContent="DetNet-OAM"/> of "Framework ofOAM for DetNet" </xref>Operations, Administration, and Maintenance (OAM) for Deterministic Networking (DetNet)" <xreftarget="RFC7799">"Activetarget="RFC9551" format="default" sectionFormat="of" derivedContent="DetNet-OAM"/> and in "Active and Passive Metrics and Methods (with Hybrid Types In-Between)"</xref>. <!-- <xref target="I-D.ietf-opsawg-oam-characterization">"Guidelines for Characterizing OAM"</xref> provides additional semantics of the terms Active, Passive, Hybrid, and In-Packet OAM that are consistent with <xref target="RFC7799"/>. It also warns about potential inconsistencies in the way the terms "in-band" and "out-of-band" are used across the IETF; the DetNet reference for those terms is<xreftarget="RFC9551"/>. --> </t> <t>target="RFC7799" format="default" sectionFormat="of" derivedContent="RFC7799"/>. </t> <t indent="0" pn="section-3-3"> RAW also reuses terminology defined for MPLS in <xreftarget= "RFC4427" format="default"/>target="RFC4427" format="default" sectionFormat="of" derivedContent="RFC4427"/>, such as the termrecovery as covering"recovery" to cover bothProtectionprotection andRestoration,restoration for a number of recovery types. That document defines a number ofconceptsconcepts, such as the recoverydomaindomain, that are used intheRAWmechanisms,mechanisms and defines the new termrecovery graph."recovery graph". A recovery graph associates a topological graph with usage metadata that represents how the paths are built and used within the recovery graph. The recovery graph provides excess bandwidth for the intended traffic over alternate potential paths, and the use of that bandwidth is optimized dynamically. </t><t><t indent="0" pn="section-3-4"> The concept of a recovery graph is agnostic to the underlying technology and applies, but is not limited to, any full or partial wireless mesh. RAW specifies strict and loose recovery graphs depending on whether the path is fully controlled by RAW or traverses an opaque network where RAW cannot observe and control the individual hops. </t> <t indent="0" pn="section-3-5"> RAW also reuses terminology defined for RSVP-TE in <xreftarget= "RFC4090" format="default"/>target="RFC4090" format="default" sectionFormat="of" derivedContent="RFC4090"/>, such as thePoint"Point of Local Repair(PLR).(PLR)". The concept of a backup path is generalized with protection path, which is the term mostly found in recent standards and used in this document. </t><t><t indent="0" pn="section-3-6"> RAW also reuses terminology defined for 6TiSCH in <xreftarget= "RFC9030" format="default"/>target="RFC9030" format="default" sectionFormat="of" derivedContent="6TiSCH-ARCH"/> and equates the 6TiSCH concept of a Track with that of a recovery graph. </t><t> The concept of recovery graph is agnostic to the underlying technology and applies but is not limited to any full or partial wireless mesh. RAW specifies strict and loose recovery graphs depending on whether the path is fully controlled by RAW or traverses an opaque network where RAW cannot observe and control the individual hops. </t> <t> RAW<section numbered="true" removeInRFC="false" toc="include" pn="section-3.1"> <name slugifiedName="name-abbreviations">Abbreviations</name> <t indent="0" pn="section-3.1-1">RAW uses the followingterminology and acronyms: </t> <section><name>Acronyms</name> <section><name>ARQ</name> <t>abbreviations.</t> <dl newline="true" indent="3" spacing="normal" pn="section-3.1-2"> <dt pn="section-3.1-2.1">ARQ</dt> <dd pn="section-3.1-2.2"> Automatic RepeatRequest, aRequest. A well-knownmechanism, enablingmechanism that enables an acknowledged transmission with retries to mitigate errors and loss. ARQ may be implemented at various layers in a network. ARQ is typically implementedat Layer-2,per hopand not end-to-end(not end to end) at Layer 2 in wireless networks. ARQ improves delivery on lossy wireless. Additionally, ARQ retransmission may be further limited by a bounded time to meet end-to-end packet latency constraints. Additional details and considerations for ARQ are detailed in <xreftarget="RFC3366"/>. </t> </section> <section><name>FEC</name> <t>target="RFC3366" format="default" sectionFormat="of" derivedContent="RFC3366"/>. </dd> <dt pn="section-3.1-2.3">FEC</dt> <dd pn="section-3.1-2.4"> Forward ErrorCorrection, addingCorrection. Adding redundant data to protect against a partial loss without retries.</t> </section> <section><name>HARQ</name> <t></dd> <dt pn="section-3.1-2.5">HARQ</dt> <dd pn="section-3.1-2.6"> HybridARQ, combiningARQ. A combination of FEC and ARQ.</t> </section> <section><name>ETX</name> <t></dd> <dt pn="section-3.1-2.7">ETX</dt> <dd pn="section-3.1-2.8"> Expected TransmissionCount: aCount. A statistical metric that represents the expected total number of packet transmissions (including retransmissions) required to successfully deliver a packet along a path, used by 6TiSCH <xreftarget="RFC6551"/>. </t> </section> <section><name>ISM</name> <t> The industrial, scientific,target="RFC6551" format="default" sectionFormat="of" derivedContent="RFC6551"/>. </dd> <dt pn="section-3.1-2.9">ISM</dt> <dd pn="section-3.1-2.10"> Industrial, Scientific, andmedical (ISM) radio band refersMedical. Refers to a group of radio bands or parts of the radio spectrum (e.g., 2.4 GHz and 5 GHz) that are internationally reserved for the use of radio frequency (RF) energy intended for industrial, scientific,medical,andindustrial requirements, e.g.,medical requirements (e.g., by microwaves, depth radars, and medical diathermymachines.machines). Cordless phones, Bluetooth andLoWPANLow-Power Wireless Personal Area Network (LoWPAN) devices, near-field communication (NFC) devices, garage door openers, baby monitors, and Wi-Fi networks may all use the ISM frequencies, although these low-power transmitters are not considered to be ISM devices. In general, communications equipment operating in ISM bands must tolerate any interference generated by ISM applications, and users have no regulatory protection from ISM device operation in these bands.</t> </section> <section><name>PER and PDR</name> <t> The</dd> <dt pn="section-3.1-2.11">PER</dt> <dd pn="section-3.1-2.12"> Packet ErrorRate (PER) is defined as theRate. The ratio of the number of packets received in error to the total number of transmitted packets. A packet is considered to be in error if even a single bit within the packet is received incorrectly.In contrast, the</dd> <dt pn="section-3.1-2.13">PDR</dt> <dd pn="section-3.1-2.14"> Packet Delivery Ratio(PDR) indicates the(PDR). The ratio of the numbersuccessful deliveryof successfully delivered data packets to the total number oftransmittedpackets transmitted from the sender to the receiver.</t> </section> <section><name>RSSI</name> <t></dd> <dt pn="section-3.1-2.15">RSSI</dt> <dd pn="section-3.1-2.16"> Received Signal StrengthIndication (a.k.a. EnergyIndication. Also known as "Energy DetectionLevel): aLevel". A measure of the incoherent (raw) RF power in a channel. The RF power can come from any source: other transmitters using the same technology, other radio technology using the same band, or background radiation. For asingle-hop,single hop, RSSI may be used for LQI.</t> </section> <section><name>LQI</name> <t> The link quality indicator (LQI) is an</dd> <dt pn="section-3.1-2.17">LQI</dt> <dd pn="section-3.1-2.18"> Link Quality Indicator. An indication of the quality of the data packets received by the receiver. It is typically derived from packet error statistics, with the exact method depending on the network stack being used. LQI values may be exposed to thecontroller planeController Plane for each individual hop or cumulated along segments. Outgoing LQI values can be calculated from coherent (demodulated) PER,RSSIRSSI, and incoming LQI values.</t> </section> <section><name>OAM</name> <t> OAM stands for</dd> <dt pn="section-3.1-2.19">OAM</dt> <dd pn="section-3.1-2.20"> Operations, Administration, andMaintenance, and coversMaintenance. Covers the processes, activities, tools, and standards involved with operating, administering, managing, and maintaining any system. This document uses theterms Operations, Administration, and Maintenance,term in conformance withthe <xref target="RFC6291"> 'Guidelines"Guidelines for the Use of the"OAM"'OAM' Acronym in theIETF'</xref>IETF" <xref target="RFC6291" format="default" sectionFormat="of" derivedContent="RFC6291"/>, and the system observed by the RAW OAM is the recovery graph.</t> </section> <section><name>OODA</name> <t> OODA (Observe,</dd> <dt pn="section-3.1-2.21">OODA</dt> <dd pn="section-3.1-2.22"> Observe, Orient, Decide,Act) is aAct. A generic formalism to represent the operational steps in aControl Loop.control loop. In the context of RAW, OODA is applied to network control andconvergence, more inconvergence; see <xreftarget="ooda"/>. </t> </section> <section><name>SNR</name> <t> Signal-Noise Ratio (a.k.a. S/N): atarget="ooda" format="default" sectionFormat="of" derivedContent="Section 6.2"/> for more. </dd> <dt pn="section-3.1-2.23">SNR</dt> <dd pn="section-3.1-2.24"> Signal-to-Noise Ratio. Also known as "S/N Ratio". A measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to noise power, often expressed in decibels.</t></dd> </dl> </section></section><!--Acronyms--> <section><name>Link<section numbered="true" removeInRFC="false" toc="include" pn="section-3.2"> <name slugifiedName="name-link-and-direction">Link and Direction</name><section><name>Flapping</name> <t><t indent="0" pn="section-3.2-1">This document uses the following terms relating to links and direction in the context of RAW.</t> <section numbered="true" removeInRFC="false" toc="include" pn="section-3.2.1"> <name slugifiedName="name-flapping">Flapping</name> <t indent="0" pn="section-3.2.1-1"> In the context of RAW, a link flaps when the reliability of the wireless connectivity drops abruptly for a short period of time, typically a duration of a subsecond toseconds duration.seconds. </t> </section><section><name>Uplink</name> <t> Connection<section numbered="true" removeInRFC="false" toc="include" pn="section-3.2.2"> <name slugifiedName="name-uplink">Uplink</name> <t indent="0" pn="section-3.2.2-1"> An uplink is the connection fromend-devicesend devices to data communication equipment. In the context of wireless, uplink refers to the connection between a station (STA) and a controller (AP) or a User Equipment (UE)toand a Base Station (BS) such as a 3GPP 5G gNodeB(gNb).(gNB). </t> </section><section><name>Downlink</name> <t> The<section numbered="true" removeInRFC="false" toc="include" pn="section-3.2.3"> <name slugifiedName="name-downlink">Downlink</name> <t indent="0" pn="section-3.2.3-1"> A downlink is the reverse direction from uplink. </t> </section><section><name>Downstream</name> <t> Following<section numbered="true" removeInRFC="false" toc="include" pn="section-3.2.4"> <name slugifiedName="name-downstream">Downstream</name> <t indent="0" pn="section-3.2.4-1"> Downstream refers to the following the direction of the flow data path along a recovery graph. </t> </section><section><name>Upstream</name> <t> Against<section numbered="true" removeInRFC="false" toc="include" pn="section-3.2.5"> <name slugifiedName="name-upstream">Upstream</name> <t indent="0" pn="section-3.2.5-1"> Upstream refers to going against the direction of the flow data path along a recovery graph. </t> </section></section><!-- Link and Direction --></section> <sectionanchor="pt"><name>Pathanchor="pt" numbered="true" removeInRFC="false" toc="include" pn="section-3.3"> <name slugifiedName="name-path-and-recovery-graphs">Path and Recovery Graphs</name><section><name>Path</name> <t> Quoting section 1.1.3<t indent="0" pn="section-3.3-1">This document uses the following terms relating to paths and recovery graphs in the context of RAW.</t> <section numbered="true" removeInRFC="false" toc="include" pn="section-3.3.1"> <name slugifiedName="name-path">Path</name> <t indent="0" pn="section-3.3.1-1"> <xreftarget="RFC1122"/>:target="RFC1122" section="1.3.3" format="default" sectionFormat="of" derivedLink="https://rfc-editor.org/rfc/rfc1122#section-1.3.3" derivedContent="INT-ARCH"/> provides a definition of path: </t><blockquote><blockquote pn="section-3.3.1-2"> At a given moment, all the IP datagrams from a particular source host to a particular destination host will typically traverse the same sequence of gateways. We use the term "path" for this sequence. Note that a path isunidirectional;uni-directional; it is not unusual to have different paths in the two directions between a given host pair. </blockquote><t> Section 2 of <xref target="RFC9473"/><t indent="0" pn="section-3.3.1-3"> <xref target="RFC9473" section="2" format="default" sectionFormat="of" derivedLink="https://rfc-editor.org/rfc/rfc9473#section-2" derivedContent="RFC9473"/> points to a longer, more modern definition of path, which begins as follows: </t><blockquote> <t><blockquote pn="section-3.3.1-4"> <t indent="0" pn="section-3.3.1-4.1"> A sequence of adjacent path elements over which a packet can be transmitted, starting and ending with a node.</t><t></t> <t indent="0" pn="section-3.3.1-4.2"> Paths are unidirectional andtime-dependent,time dependent, i.e., there can be a variety of paths from one node to another, and the path over which packets are transmitted may change. A path definition can befixedstrict (i.e., the exact sequence of path elements remains the same) ormutableloose (i.e., the start and end node remain the same, but the path elements between them may vary over time).</t><t></t> <t indent="0" pn="section-3.3.1-4.3"> The representation of a path and its properties may depend on the entity considering the path. On the one hand, the representation may differ due to entities having partial visibility of path elements comprising a path or their visibility changing over time. </t> </blockquote><t><t indent="0" pn="section-3.3.1-5"> It follows that the general acceptance of a path is a linear sequence of links and nodes, as opposed to a multi-dimensional graph, defined by the experience of the packet that went from a node A to a node B. In the context of this document, a path is observed by following one copy or one fragment of a packet that conserves its uniqueness and integrity. For instance, if C replicates to E and F and if D eliminates duplicates, a packet from A to B can experience2 paths, A->C->E->D->Btwo paths: A->C->E->D->B andA->C->F->D->B.A->C->F->D->B. Those paths are called protection paths. Protection paths may be fullynon-congruent, and alternativelynon-congruent; alternatively, they may intersect at replication or elimination points. </t><t><t indent="0" pn="section-3.3.1-6"> With DetNet and RAW, a packet may be duplicated, fragmented, andnetwork-coded,network coded, and the various byproducts may travel different paths that are not necessarilyend-to-endend to end between A andB; weB. We refer tothatthis complex scenario as a DetNet path. As such, the DetNet path extends the above description of a path, but it still matches the experience of a packet that traverses the network. </t><t><t indent="0" pn="section-3.3.1-7"> With RAW, the path experienced by a packet is subject to change from one packet to the next, but all the possible experiences are all contained within a finite set. Therefore, we introducebelowthe termof a recovery graph"recovery graph" (see the next section) that coalesces that set and covers the overall topology where the possible DetNet paths are all contained. As such, the recovery graph coalesces all the possible paths a flow may experience, each with its own statistical probability to be used. </t> </section> <sectionanchor="trk"><name>Recoveryanchor="trk" numbered="true" removeInRFC="false" toc="include" pn="section-3.3.2"> <name slugifiedName="name-recovery-graph">Recovery Graph</name><t>A<t indent="0" pn="section-3.3.2-1">A recovery graph is a networking graph that can be followed to transport packets with equivalenttreatment,treatment and is associated with usagemetadata; as opposedmetadata. In contrast to the definition of a path above, a recovery graph represents a potential path, not an actualbutone. Also, apotential, itrecovery graph is not necessarily a linear sequence like a simplepath,path and is not necessarily fully traversed (flooded) by all packets of a flow like a DetNetPath.path. Still, and as a simplification, the casual reader may consider that a recovery graph is very much like a DetNet path, aggregating multiple paths that mayoverlap,overlap or fork and then rejoin, forinstanceinstance, to enable a protection service by the PREOF operations. </t> <figureanchor="Figtrk"> <name>Exampleanchor="Figtrk" align="left" suppress-title="false" pn="figure-1"> <name slugifiedName="name-example-iot-recovery-graph-">Example IoT Recovery Graph to an IoT Gateway with 1+1 Redundancy</name> <artwork align="center" name="" type=""alt=""> <![CDATA[alt="" pn="section-3.3.2-2.1"> _________ | | | IoT G/W | |_________| EGRESS<<===<<=== Elimination at Egress | | ---+--------+--+--------+-------- | Backbone | __|__ __|__ | | Backbone | | Backbone |__ __| Router |__ __| Router | # | # \ # /<--<-- protection path # # #-------# \ # / # ( Low-power ) # # \ / # ( Lossy Network) \ / # INGRESS<<===<<=== Replication at recovery graphIngressingress | #<--<-- source device #: Low-power device]]></artwork> </figure><t><t indent="0" pn="section-3.3.2-3"> Refining further, a recovery graph is defined as the coalescence ofthe collection ofall the feasible DetNetPathspaths that a packetfor which a flow iswith an assignedto the recovery graphflow may be forwarded along. A packet that is assigned to the recovery graph experiences one of the feasible DetNetPathspaths based on the current selection by the PLR at the time the packet traverses the network. </t><t><t indent="0" pn="section-3.3.2-4"> Refining even further, the feasible DetNetPathspaths within the recovery graph may or may not be computed inadvance, butadvance; instead, they may be decided upon the detection of a change from a clean slate. Furthermore, the PLR decision may be distributed, which yields a large combination of possible and dependent decisions, with no node in the network capable of reporting which is the current DetNetPathpath within the recovery graph. </t><t><t indent="0" pn="section-3.3.2-5"> In DetNet <xreftarget="RFC8655"/>target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/> terms, a recovery graph has the following properties: </t><ul> <li><ul bare="false" empty="false" indent="3" spacing="normal" pn="section-3.3.2-6"> <li pn="section-3.3.2-6.1"> A recovery graph is aLayer-3Layer 3 abstraction built upon IP links between routers. A router may form multiple IP links over a single radio interface.</li><li></li> <li pn="section-3.3.2-6.2"> A recovery graph has oneIngressingress and oneEgressegress node, which operate as DetNetEdgeedge nodes.</li><li> The graph of a</li> <li pn="section-3.3.2-6.3"> A recovery graph is reversible, meaning that packets can be routed against the flow of data packets, e.g., to carry OAM measurements or control messages back to theIngress. </li><li>ingress. </li> <li pn="section-3.3.2-6.4"> The vertices ofthata recovery graph are DetNetRelay Nodesrelay nodes that operate at the DetNet Service sub-layer and provide the PREOF functions.</li><li></li> <li pn="section-3.3.2-6.5"> The topological edges ofthea recovery graph are strict sequences of DetNetTransittransit nodes that operate at the DetNetForwardingforwarding sub-layer. </li> </ul><t> <xref target='TRK'/><t indent="0" pn="section-3.3.2-7"> <xref target="TRK" format="default" sectionFormat="of" derivedContent="Figure 2"/> illustrates the generic concept of a recovery graph, between anIngress Nodeingress node and anEgress Node.egress node. The recovery graph is composed of forward protectionpaths andpaths, forwardorsegments, and crossingSegmentssegments (see thedefinition fordefinitions of those terms in the next sections). The recovery graph contains at least2two protectionpaths aspaths: a main path and a backup path. </t> <figureanchor='TRK'><name>Aanchor="TRK" align="left" suppress-title="false" pn="figure-2"> <name slugifiedName="name-a-recovery-graph-and-its-co">A Recovery Graph anditsIts Components</name> <artworkalign="center"><![CDATA[align="center" pn="section-3.3.2-8.1"> ------------------- forward direction---------------------->----------------------> a==>==> b==>==> C -=- F==>==> G==>==> h T1I: Ingress/ \ / | \ /E: EgressI o n E -=- T2T1, T2, T3:\ / \ | / \Externalp==>==> q==>==> R -=- T==>==> U==>==> v T3TargetsI: Ingress E: Egress T1, T2, T3: external targets Uppercase: DetNetRelay Nodesrelay nodes Lowercase: DetNetTransittransit nodesI ==></artwork> </figure> <t indent="0" pn="section-3.3.2-9">Of note:</t> <dl newline="false" spacing="normal" indent="3" pn="section-3.3.2-10"> <dt pn="section-3.3.2-10.1">I ==> a==>==> b==> C : A==> C:</dt> <dd pn="section-3.3.2-10.2">A forwardSegmentsegment to targets F and o</dd> <dt pn="section-3.3.2-10.3">C ==> oC ==> o ==> T: A==> T:</dt> <dd pn="section-3.3.2-10.4">A forwardSegmentsegment to target T (and/orU) GU)</dd> <dt pn="section-3.3.2-10.5">G | n |U : AU:</dt> <dd pn="section-3.3.2-10.6">A crossingSegmentsegment to targets G orU I ->U</dd> <dt pn="section-3.3.2-10.7">I -> F-> E : A-> E:</dt> <dd pn="section-3.3.2-10.8">A forwardProtection Pathprotection path to targets T1, T2, andT3 I,T3</dd> <dt pn="section-3.3.2-10.9">I, a, b, C, F, G, h,E : aE:</dt> <dd pn="section-3.3.2-10.10">A path to T1, T2, and/orT3 I,T3</dd> <dt pn="section-3.3.2-10.11">I, p, q, R, o, F, G, h,E :E:</dt> <dd pn="section-3.3.2-10.12">A segment-crossing protectionpath ]]></artwork> </figure>path</dd> </dl> </section><section><name>Forward<section numbered="true" removeInRFC="false" toc="include" pn="section-3.3.3"> <name slugifiedName="name-forward-and-crossing">Forward and Crossing</name><t><t indent="0" pn="section-3.3.3-1"> Forward refers to progress towards the egress of the recoverygraph Egress.graph. Forward links are directional, and packets that are forwarded along the recovery graph can only be transmitted along the link direction. Crossing links are bidirectional, meaning that they can be used in both directions, though a given packet may use the link in one direction only. ASegmentsegment can be forward, in which case it is composed of forward links only, or it can be crossing, in which case it is composed of crossing links only. AProtection Pathprotection path is always forward, meaning that it is composed of forward links andSegments.segments. </t> </section><section><name>Protection<section numbered="true" removeInRFC="false" toc="include" pn="section-3.3.4"> <name slugifiedName="name-protection-path">Protection Path</name><t> An<t indent="0" pn="section-3.3.4-1"> A protection path is an end-to-end forward path between theIngressingress andEgress Nodesegress nodes of a recovery graph. A protection path in a recovery graph is expressed as a strict sequence of DetNetRelay Nodesrelay nodes or as a loose sequence of DetNetRelay Nodesrelay nodes that are joined by segments in the recoverygraph Segments.graph. Background information on the concepts related to protection paths can be found in <xreftarget="RFC4427"/>target="RFC4427" format="default" sectionFormat="of" derivedContent="RFC4427"/> and <xreftarget="RFC6378"/>target="RFC6378" format="default" sectionFormat="of" derivedContent="RFC6378"/>. </t> </section><section><name>Segment</name> <t><section numbered="true" removeInRFC="false" toc="include" pn="section-3.3.5"> <name slugifiedName="name-segment">Segment</name> <t indent="0" pn="section-3.3.5-1"> A segment is a strict sequence of DetNetTransittransit nodes between2two DetNetRelay Nodes;relay nodes; aSegmentsegment of a recovery graph is composed topologically of two vertices of the recovery graph and one edge of the recovery graph between those vertices. </t> </section></section><!--Path and recovery graphs--> <section><name>Deterministic</section> <section numbered="true" removeInRFC="false" toc="include" pn="section-3.4"> <name slugifiedName="name-deterministic-networking">Deterministic Networking</name><t>This<t indent="0" pn="section-3.4-1">This document reuses the terminology insection 2 of<xreftarget="RFC8557"/>target="RFC8557" section="2" format="default" sectionFormat="of" derivedLink="https://rfc-editor.org/rfc/rfc8557#section-2" derivedContent="RFC8557"/> andsection 4.1.2 of<xreftarget="RFC8655"/>target="RFC8655" section="4.1.2" format="default" sectionFormat="of" derivedLink="https://rfc-editor.org/rfc/rfc8655#section-4.1.2" derivedContent="DetNet-ARCH"/> for deterministic networking and deterministic networks. This document also uses the following terms. </t><section><name>The<section numbered="true" removeInRFC="false" toc="include" pn="section-3.4.1"> <name slugifiedName="name-the-detnet-planes">The DetNet Planes</name><t><t indent="0" pn="section-3.4.1-1"> <xreftarget="RFC8655"/>target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/> defines three planes: the Application (User) Plane, the Controller Plane, and the Network Plane. The DetNet Network Plane is composed of a Data Plane (packet forwarding) and an Operational Plane where OAM operations take place. In the Network Plane, the DetNet Service sub-layer focuses on flow protection (e.g., using redundancy) and can be fully operated atLayer-3,Layer 3, while the DetNet forwarding sub-layer establishes the paths, associates the flows to the paths,andensures the availability of the necessary resources, and leveragesLayer-2Layer 2 functionalities for timely delivery to the next DetNetsystem,system. For moreininformation, see <xreftarget='problem'/>.target="problem" format="default" sectionFormat="of" derivedContent="Section 2"/>. </t> </section><section><name>Flow</name> <t><section numbered="true" removeInRFC="false" toc="include" pn="section-3.4.2"> <name slugifiedName="name-flow">Flow</name> <t indent="0" pn="section-3.4.2-1"> A flow is a collection of consecutive IP packets defined by the upper layers and signaled by the same55-tuple or 6-tuple (seesection 5.1 of<xreftarget="RFC8939"/>).target="RFC8939" section="5.1" format="default" sectionFormat="of" derivedLink="https://rfc-editor.org/rfc/rfc8939#section-5.1" derivedContent="RFC8939"/>). Packets of the same flow must be placed on the same recovery graph to receive an equivalent treatment fromIngressingress toEgressegress within the recovery graph. Multiple flows may be transported along the same recovery graph. The DetNetPathpath that is selected for the flow may change over time under the control of the PLR. </t> </section><section><name>Residence<section numbered="true" removeInRFC="false" toc="include" pn="section-3.4.3"> <name slugifiedName="name-residence-time">Residence Time</name><t><t indent="0" pn="section-3.4.3-1"> A residence time (RT) is defined as the time interval between when the reception of a packet starts and the transmission of the packet begins. In the context of RAW, RT is useful for a transitnode,nodes, not ingress oregress.egress nodes. </t> </section><section><name>L3<section numbered="true" removeInRFC="false" toc="include" pn="section-3.4.4"> <name slugifiedName="name-l3-deterministic-flow-ident">L3 Deterministic Flow Identifier </name><t> See section 3.3 of <xref target="RFC8938"/>.<t indent="0" pn="section-3.4.4-1"> The classic IP 5-tuple that identifies a flow comprises the source IP, destination IP, source port, destination port, and theupper layer protocolUpper-Layer Protocol (ULP). DetNet uses a 6-tuple where the extra field is theDSCPDifferentiated Services Code Point (DSCP) field in thepacket.packet (see <xref target="RFC8938" section="3.3" format="default" sectionFormat="of" derivedLink="https://rfc-editor.org/rfc/rfc8938#section-3.3" derivedContent="DetNet-DP"/>). The IPv6 flow label is not used for that purpose. </t> </section><section><name>TSN</name> <t> TSN stands for<section numbered="true" removeInRFC="false" toc="include" pn="section-3.4.5"> <name slugifiedName="name-time-sensitive-networking">Time-Sensitive Networking</name> <t indent="0" pn="section-3.4.5-1"> Time-Sensitive Networkingand(TSN) denotes theefforts atIEEE 802forefforts regarding deterministic networking, originally for use on Ethernet. See <xref target="TSN" format="default" sectionFormat="of" derivedContent="TSN"/>. Wireless TSN (WTSN) denotes extensions of the TSN work on wirelessmedia such asmedia, e.g., theselectedRAW technologies described in <xreftarget="I-D.ietf-raw-technologies"/>.target="RFC9913" format="default" sectionFormat="of" derivedContent="RAW-TECHNOS"/>. </t> </section><section><name>Lower-Layer<section numbered="true" removeInRFC="false" toc="include" pn="section-3.4.6"> <name slugifiedName="name-lower-layer-api">Lower-Layer API</name><t> In addition,<t indent="0" pn="section-3.4.6-1"> RAW includes the concept of a lower-layer API (LLAPI),API) that provides an interface between thelower layerlower-layer (e.g., wireless) technology and the DetNet layers. The LL API is technology dependent as what the lower layers expose towards the DetNet layers may vary. Furthermore,thedifferent RAW technologies are equipped with different reliabilityfeatures, e.g., short rangefeatures (e.g., short-range broadcast,Multiple-User, Multiple-Input, and Multiple-Output (MUMIMO), PHYMultiple User - Multiple Input Multiple Output (MU-MIMO), physical layer (PHY) rate and other Modulation Coding Scheme (MCS) adaptation, coding and retransmissions methods, and constructive interference andoverhearing,overhearing; see <xreftarget="I-D.ietf-raw-technologies"/>target="RFC9913" format="default" sectionFormat="of" derivedContent="RAW-TECHNOS"/> fordetails.more details). The LL API enables interactions between the reliability functions provided by the lower layer and the reliability functions provided by DetNet. That is, the LL API makes cross-layer optimization possible for the reliability functions of different layers depending on the actual exposure provided via the LL API by the given RAW technology. The <xreftarget="RFC8175"> Dynamicformat="title" target="RFC8175" sectionFormat="of" derivedContent="Dynamic Link Exchange Protocol(DLEP) </xref>(DLEP)"/> <xref target="RFC8175" format="default" sectionFormat="of" derivedContent="DLEP"/> is an example of a protocol that can be used to implement the LL API. </t> </section></section><!--Deterministic Networking --> <section><name>Reliability</section> <section numbered="true" removeInRFC="false" toc="include" pn="section-3.5"> <name slugifiedName="name-reliability-and-availabilit">Reliability and Availability</name><t> In<t indent="0" pn="section-3.5-1">In the context of the RAW work,Reliabilityreliability andAvailabilityavailability are defined asfollows: </t> <section><name>Servicefollows, along with the following other terms.</t> <section numbered="true" removeInRFC="false" toc="include" pn="section-3.5.1"> <name slugifiedName="name-service-level-agreement">Service Level Agreement</name><t><t indent="0" pn="section-3.5.1-1"> In the context of RAW,an SLA (service level agreement)a Service Level Agreement (SLA) is a contract between a provider (the network) and aclient, theclient (the applicationflow, definingflow) that defines measurable metrics such as latency boundaries, consecutive losses, andpacket delivery ratioPacket Delivery Ratio (PDR). </t> </section><section><name>Service<section numbered="true" removeInRFC="false" toc="include" pn="section-3.5.2"> <name slugifiedName="name-service-level-objective">Service Level Objective</name><t><t indent="0" pn="section-3.5.2-1"> Aservice level objectiveService Level Objective (SLO) is one term in the SLA, for which specific network setting and operations are implemented. For instance, a dynamic tuning ofthepacket redundancy addresses an SLO of consecutive losses in a row by augmenting the chances of delivery of a packet that follows a loss. </t> </section><section><name>Service<section numbered="true" removeInRFC="false" toc="include" pn="section-3.5.3"> <name slugifiedName="name-service-level-indicator">Service Level Indicator</name><t><t indent="0" pn="section-3.5.3-1"> Aservice level indicatorService Level Indicator (SLI) measures the compliance of an SLO to the terms of the contract.ItFor instance, it can befor instance,the statistics of individual lossesandor losses in a rowas time series.during a certain amount of time. </t> </section><section><name> Precision<section numbered="true" removeInRFC="false" toc="include" pn="section-3.5.4"> <name slugifiedName="name-precision-availability-metr">Precision Availability Metrics</name><t><t indent="0" pn="section-3.5.4-1"> Precision Availability Metrics (PAMs) <xreftarget="RFC9544"/>target="RFC9544" format="default" sectionFormat="of" derivedContent="RFC9544"/> aimat capturingto capture service levels for a flow, specifically the degree to which the flow complies with the SLOs that are in effect. </t> </section><section><name>Reliability</name> <t><section numbered="true" removeInRFC="false" toc="include" pn="section-3.5.5"> <name slugifiedName="name-reliability">Reliability</name> <t indent="0" pn="section-3.5.5-1"> Reliability is a measure of the probability that an item (e.g.,system,system or network) will perform its intended function with no failure for a stated period of time (or for a stated number of demands or load) under stated environmental conditions. In other words, reliability is the probability that an item will be in an uptime state (i.e., fully operational or ready to perform) for a statedmission, e.g.,mission (e.g., to provide anSLA.SLA). See more in <xreftarget="NASA1"/>.target="NASA1" format="default" sectionFormat="of" derivedContent="NASA1"/>. </t> </section><section><name>Availability</name> <t><section numbered="true" removeInRFC="false" toc="include" pn="section-3.5.6"> <name slugifiedName="name-availability">Availability</name> <t indent="0" pn="section-3.5.6-1"> Availability is the probability of anitem’sitem's (e.g., anetwork’s)network's) mission readiness (e.g., to provide anSLA), an uptime state with the likelihood of a recoverable downtime state.SLA). Availability is expressed as (uptime)/(uptime+downtime). Note that it is availability that addresses downtime (including time for maintenance, repair, and replacement activities) and not reliability. See more in <xreftarget="NASA2"/>.target="NASA2" format="default" sectionFormat="of" derivedContent="NASA2"/>. </t> </section></section><!--Reliability and Availability--> </section><!-- Terminology --> <!-- 1111111111111111 --></section> </section> <section anchor="raw" numbered="true"toc="default"> <name>Reliabletoc="include" removeInRFC="false" pn="section-4"> <name slugifiedName="name-reliable-and-available-wire">Reliable and Available Wireless</name><!-- 2222222222222222 --><section numbered="true"toc="default"> <name>Hightoc="include" removeInRFC="false" pn="section-4.1"> <name slugifiedName="name-high-availability-engineeri">High Availability Engineering Principles</name><t><t indent="0" pn="section-4.1-1"> The reliability criteria of a critical system pervadethroughits elements, and if the system comprises a datanetwork andnetwork, then the data network is also subject to the inherited reliability and availability criteria. It is only natural to consider the art of high availability engineering and apply it to wireless communications in the context of RAW. </t><t><t indent="0" pn="section-4.1-2"> There are three principles (pillars) of high availability engineering: </t> <olspacing="compact"> <li>eliminationindent="adaptive" spacing="normal" start="1" type="1" pn="section-4.1-3"> <li pn="section-4.1-3.1" derivedCounter="1.">elimination of each single point of failure</li><li>reliable<li pn="section-4.1-3.2" derivedCounter="2.">reliable crossover</li><li>prompt<li pn="section-4.1-3.3" derivedCounter="3.">prompt detection of failures as they occur</li> </ol><t><t indent="0" pn="section-4.1-4"> These principles are common to all high availability systems, not just ones with Internet technology at the center.Examples of bothBoth non-Internet and Internet examples are included. </t><!-- 333333333333333333333 --><section numbered="true"toc="default"> <name>Eliminationtoc="include" removeInRFC="false" pn="section-4.1.1"> <name slugifiedName="name-elimination-of-single-point">Elimination of Single Points of Failure</name><t><t indent="0" pn="section-4.1.1-1"> Physical and logical components in a system happen to fail, either as the effect of wear and tear, when used beyond acceptable limits, or due to a software bug. It is necessary to decouple component failure from system failure to avoid the latter. This allows failed components to be restored while the rest of the system continues to function. </t><t><t indent="0" pn="section-4.1.1-2"> IPRoutersrouters leverage routing protocols to reroute to alternate routes in case of a failure. When links are cabled through the same conduit, they form ashared risk link group (SRLG),Shared Risk Link Group (SRLG) and share the same fate if the conduit is cut, making the reroute operation ineffective. The same effect can happen with virtual links that end up inathe same physical transport through the intricacies of nested encapsulation. Inathe same fashion, an interferer or an obstacle may affect multiple wireless transmissions at the same time, even between different sets of peers. </t><t><t indent="0" pn="section-4.1.1-3"> Intermediate networkNodes suchnodes (such as routers, switches and APs, wire bundles, and the air mediumitselfitself) can become single points of failure.For High Availability, it is thus required toThus, for high availability, the use of physically link-disjoint andNode-disjoint paths;node-disjoint paths is required; in the wireless space,it is also required tothe use of the highest possible degree of diversity (time, space, code, frequency, and channel width) in the transmissions over the air is also required to combat the additional causes of transmission loss. </t><t><t indent="0" pn="section-4.1.1-4"> From an economics standpoint, executing this principle properly generally increases capital expense because of the redundant equipment. In a constrained network where the waste of energy and bandwidth should be minimized, an excessive use of redundant links must be avoided; forRAWRAW, this means that the extra bandwidth must be used wisely and efficiently. </t> </section><!--Elimination of Single Points of Failure--> <!-- 333333333333333333333 --><section numbered="true"toc="default"> <name>Reliabletoc="include" removeInRFC="false" pn="section-4.1.2"> <name slugifiedName="name-reliable-crossover">Reliable Crossover</name><t> Having backup<t indent="0" pn="section-4.1.2-1"> Backup equipment hasalimited value unless it can be reliably switched into use within thedown-timedowntime parameters. IPRoutersrouters execute reliable crossover continuously because the routers use any alternate routes that are available <xreftarget= "RFC0791"/>.target="RFC0791" format="default" sectionFormat="of" derivedContent="RFC0791"/>. This is due to the stateless nature of IP datagrams and the dissociation of the datagrams from the forwarding routes they take.The <xref target="RFC5714">"IP"IP Fast RerouteFramework"</xref>Framework" <xref target="RFC5714" format="default" sectionFormat="of" derivedContent="FRR"/> analyzes mechanisms for fast failure detection and path repair for IPFast-Reroute (FRR),Fast Reroute (FRR) and discusses the case of multiple failures and SRLG. Examples of FRR techniques include Remote Loop-Free Alternate <xreftarget="RFC7490"/>target="RFC7490" format="default" sectionFormat="of" derivedContent="RLFA-FRR"/> and backuplabel-switched pathLabel Switched Path (LSP) tunnels for the local repair of LSP tunnels using RSVP-TE <xreftarget="RFC4090"/>. </t> <t>target="RFC4090" format="default" sectionFormat="of" derivedContent="RFC4090"/>. </t> <t indent="0" pn="section-4.1.2-2"> Deterministic flows, on the contrary, are attached to specific paths where dedicated resources are reserved for each flow. Therefore, each DetNet path must inherently provide sufficient redundancy to provide the assured SLOs at all times. The DetNet PREOF typically leverages 1+1 redundancy whereby a packet is sent twice, over non-congruent paths. This avoids the gap during thefast reroute operation,FRR operation but doubles the traffic in the network. </t><t><t indent="0" pn="section-4.1.2-3"> In the case of RAW, the expectation is that multiple transient faults may happen in overlapping time windows, in which case the 1+1 redundancy with delayed reestablishment of the second path does not provide the required guarantees. The Data Plane must be configured with a sufficient degree of redundancy to select an alternate redundant path immediately upon a fault, without the need for a slow intervention from the Controller Plane. </t> </section><!--Reliable Crossover--> <!-- 333333333333333333333 --><section numbered="true"toc="default"> <name>Prompttoc="include" removeInRFC="false" pn="section-4.1.3"> <name slugifiedName="name-prompt-notification-of-fail">Prompt Notification of Failures</name><t><t indent="0" pn="section-4.1.3-1"> The execution of the two above principles is likely to render a system where the end user rarely sees a failure.ButHowever, a failure that occurs must still be detected in order to direct maintenance. </t><t><t indent="0" pn="section-4.1.3-2"> There are many reasons for system monitoring(FCAPS for fault, configuration, accounting, performance, security(Fault, Configuration, Accounting, Performance, and Security (FCAPS) is a handy mentalchecklist)checklist), but fault monitoring is a sufficient reason. </t><t> <xref target="RFC9522"><t indent="0" pn="section-4.1.3-3"> "Overview and Principles of Internet TrafficEngineering"</xref>Engineering" <xref target="RFC9522" format="default" sectionFormat="of" derivedContent="TE"/> discusses the importance of measurement for networkprotection,protection and provides an abstract method for network survivability with the analysis of a traffic matrix as observed via a network management YANG data model, probing techniques, file transfers, IGP link state advertisements, and more. </t><t><t indent="0" pn="section-4.1.3-4"> Those measurements are needed in the context of RAW to inform the controller and make the long-term reactive decision to rebuild a recovery graph based on statistical and aggregated information. RAW itself operates in the DetNet Network Plane at a fastertime-scaletimescale with live information on speed, state, etc. This live information can be obtained directly from the lowerlayer, e.g.,layer (e.g., using L2triggers,triggers), read from a protocol such as DLEP, or transported over multiple hops using OAM and reverse OAM, as illustrated in <xreftarget="Figlearn"/>.target="Figlearn" format="default" sectionFormat="of" derivedContent="Figure 11"/>. </t> </section><!--Prompt Notification of Failures--></section><!--Reliability Engineering--> <!-- 22222222222222222222 --><section numbered="true"toc="default"> <name>Applyingtoc="include" removeInRFC="false" pn="section-4.2"> <name slugifiedName="name-applying-reliability-concep">Applying Reliability Concepts to Networking</name><t><t indent="0" pn="section-4.2-1"> The termsReliability"reliability" andAvailability"availability" are defined for use in RAW in <xreftarget="terms"/>target="terms" format="default" sectionFormat="of" derivedContent="Section 3"/>, and the reader is invited to read <xreftarget="NASA1"/>target="NASA1" format="default" sectionFormat="of" derivedContent="NASA1"/> and <xreftarget="NASA2"/>target="NASA2" format="default" sectionFormat="of" derivedContent="NASA2"/> for more details on the general definition ofReliability.reliability. Practically speaking, a number of nines is often used to indicate the reliability of a datalink, e.g.,link (e.g., 5 nines indicate a Packet Delivery Ratio (PDR) of99.999%.99.999%). </t><t><t indent="0" pn="section-4.2-2"> This number is typical in a wired environment where the loss is due to a random event such as a solar particle that affects the transmission of a particularpacket,packet but does not affect the previousorpacket, the next packet,noror packets transmitted on other links. Note that the QoS requirements in RAW may include a bounded latency, and a packet that arrives too late is a fault and not considered as delivered. </t><t><t indent="0" pn="section-4.2-3"> For a periodic networking pattern such as an automation control loop, this number is proportional to the Mean Time Between Failures (MTBF). When a single fault can have dramatic consequences, the MTBF expresses the chances that the unwanted fault event occurs. In data networks, this is rarely the case. Packet loss cannot be fullyavoidedavoided, and the systems are built to resist someloss, e.g.,loss. This can be done by using redundancy withRetriesretries (as in HARQ), Packet Replication and Elimination (PRE) FEC, and Network Coding (e.g., using FEC withSCHC <xref target="RFC8724"/> fragments), or,Static Context Header Compression (SCHC) <xref target="RFC8724" format="default" sectionFormat="of" derivedContent="RFC8724"/> fragments). Also, in a typical control loop,bylinear interpolation from the previousmeasurements.measurements can be used. </t><t> But<t indent="0" pn="section-4.2-4"> However, the linear interpolation method cannot resist multiple consecutive losses, and a high MTBF is desired as a guarantee thatthis does not happen, in other words thatthe number oflosses-in-a-row can belosses in a row is bounded. Inthatthis case, what is really desired is a Maximum Consecutive Loss (MCL).(See also section 5.9.5 in <xref target="RFC8175"/>.)If the number of losses in a row passes the MCL, the control loop has toabortabort, and thesystem, e.g.,system (e.g., the productionline,line) may need to enter an emergency stop condition. </t><t><t indent="0" pn="section-4.2-5"> Engineers that build automated processes may use the network reliability expressed in nines asanthe MTBF and as a proxy to indicate an MCL, e.g., as described insection 7.4 of theSection <xreftarget="RFC8578">"Deterministictarget="RFC8578" sectionFormat="bare" section="7.4" format="default" derivedLink="https://rfc-editor.org/rfc/rfc8578#section-7.4" derivedContent="RFC8578"/> of "Deterministic Networking UseCases"</xref>.Cases" <xref target="RFC8578" format="default" sectionFormat="of" derivedContent="RFC8578"/>. </t> </section><!--Applying Reliability concepts to Networking--> <!-- 22222222222222222222 --><section numbered="true"toc="default"> <name>Wirelesstoc="include" removeInRFC="false" pn="section-4.3"> <name slugifiedName="name-wireless-effects-affecting-">Wireless Effects Affecting Reliability</name><t><t indent="0" pn="section-4.3-1"> In contrast with wired networks, errors in transmission are the predominant source of packet loss in wireless networks. </t><t><t indent="0" pn="section-4.3-2"> The root cause for the loss may be of multiple origins, calling for the use of different forms of diversity: </t><dl> <dt>Multipath Fading:</dt> <dd> <t>A<dl indent="3" newline="false" spacing="normal" pn="section-4.3-3"> <dt pn="section-4.3-3.1">Multipath fading:</dt> <dd pn="section-4.3-3.2"> <t indent="0" pn="section-4.3-3.2.1">A destructive interference by a reflection of the original signal. </t><t>A<t indent="0" pn="section-4.3-3.2.2">A radio signal may be received directly (line-of-sight) and/or as a reflection on a physical structure (echo). The reflections take a longer path and are delayed by the extra distance divided by the speed of light in the medium. Depending on the frequency, the echo lands with a differentphasephase, which may either add up to (constructive interference) or cancel (destructive interference) the direct signal. </t><t><t indent="0" pn="section-4.3-3.2.3"> The affected frequencies depend on the relative position of the sender, the receiver, and all the reflecting objects in the environment. A given hop suffers from multipath fading for multiple packets in a rowtilluntil a physical movement changes the reflection patterns. </t> </dd><dt>Co-channel Interference:</dt> <dd> <t><dt pn="section-4.3-3.3">Co-channel interference:</dt> <dd pn="section-4.3-3.4"> <t indent="0" pn="section-4.3-3.4.1"> Energy in the spectrum used for the transmission confuses the receiver. </t><t><t indent="0" pn="section-4.3-3.4.2"> The wireless medium itself is a Shared Risk Link Group (SRLG) for nearby users of the same spectrum, as an interference may affect multiple co-channel transmissions between different peers within the interference domain of the interferer, possibly even when they use different technologies. </t> </dd><dt>Obstacle<dt pn="section-4.3-3.5">Obstacle in FresnelZone:</dt> <dd> <t>zone:</dt> <dd pn="section-4.3-3.6"> <t indent="0" pn="section-4.3-3.6.1"> The Fresnel zone is an elliptical region of space between and around the transmit and receive antennas in a point-to-point wireless communication. The optimal transmission happens when it is free of obstacles. </t> </dd> </dl><t><t indent="0" pn="section-4.3-4"> In an environment that is rich in metallic structures and mobile objects, a single radio link provides a fuzzy service, meaning that it cannot be trusted to transport the traffic reliably over a long period of time. </t><t><t indent="0" pn="section-4.3-5"> Transmission losses are typically not independent, and their nature and duration are unpredictable; as long as a physical object (e.g., a metallic trolley between peers) that affects the transmission is not removed, or as long as the interferer (e.g., a radar in the ISM band) keeps transmitting, a continuous stream of packets are affected. </t><t><t indent="0" pn="section-4.3-6"> The key technique to combat those unpredictable losses is diversity. Different forms of diversity are necessary to combat different causes oflossloss, and the use of diversity must be maximized to optimize the PDR. </t><t><t indent="0" pn="section-4.3-7"> A single packet may be sent at different times (time diversity) over diverse paths (spatial diversity) that rely on diverse radio channels (frequency diversity)andleveraging diverse PHYtechnologies, e.g.,technologies (e.g., narrowbandvs.versus spreadspectrum,spectrum or diversecodes.codes). Using time diversity defeats short-term interferences; spatial diversity combats very local causes of interference such as multipath fading; narrowband and spread spectrum are relatively innocuous to one another and can be used for diversity in the presence of the other. </t> </section><!--Reliability in the Context of RAW--></section><!-- Reliable and Available Wireless --> <!-- 000000000000000000000 --><section anchor="model" numbered="true"toc="default"> <name>Thetoc="include" removeInRFC="false" pn="section-5"> <name slugifiedName="name-the-raw-conceptual-model">The RAW Conceptual Model</name><t><t indent="0" pn="section-5-1"> RAW extends the conceptual model described insection 4Section <xref target="RFC8655" sectionFormat="bare" section="4" format="default" derivedLink="https://rfc-editor.org/rfc/rfc8655#section-4" derivedContent="DetNet-ARCH"/> ofthe DetNet Architecture"Deterministic Networking Architecture" <xreftarget="RFC8655"/>target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/> with the PLR at the Service sub-layer, as illustrated in <xreftarget='FigLayers'/>.target="FigLayers" format="default" sectionFormat="of" derivedContent="Figure 3"/>. The PLR (see <xreftarget='PLRpce'/>) is a point of local reaction to providetarget="PLRpce" format="default" sectionFormat="of" derivedContent="Section 6.5"/>) provides additional agility against transmission loss.TheFor example, the PLR canact, e.g.,act based on indications from the lower layer or based on OAM. </t> <figureanchor="FigLayers"> <name>Extendedanchor="FigLayers" align="left" suppress-title="false" pn="figure-3"> <name slugifiedName="name-extended-detnet-data-plane-">Extended DetNetData-PlaneData Plane Protocol Stack</name> <artwork align="left" name="" type=""alt="">alt="" pn="section-5-2.1"> | packets going | ^ packets coming ^ v down the stack v | up the stack | +-----------------------+ +-----------------------+ | Source | | Destination | +-----------------------+ +-----------------------+ | Service sub-layer: | | Service sub-layer: | | Packet sequencing | | Duplicate elimination | | Flow replication | | Flow merging | | Packet encoding | | Packet decoding | | Point of Local Repair | | | +-----------------------+ +-----------------------+ | Forwarding sub-layer: | | Forwarding sub-layer: | | Resource allocation | | Resource allocation | | Explicit routes | | Explicit routes | +-----------------------+ +-----------------------+ | Lower layers | | Lower layers | +-----------------------+ +-----------------------+ v ^ \_________________________/ </artwork> </figure> <section anchor="plane" numbered="true"toc="default"> <name>Thetoc="include" removeInRFC="false" pn="section-5.1"> <name slugifiedName="name-the-raw-planes">The RAW Planes</name><t><t indent="0" pn="section-5.1-1"> The RAWNodesnodes are DetNetRelay Nodesrelay nodes that operate in the RAW Network Plane and are capable of additional diversity mechanisms and measurement functions related to the radio interface. RAW leverages an Operational Plane orientation function (that typically operates inside theIngress Edge Nodes)ingress edge nodes) to dynamically adapt the path of the packets andoptimizesoptimize the resource usage.</t><t></t> <t indent="0" pn="section-5.1-2"> In the case of centralized routing operations, the RAW Controller Plane Function (CPF) interacts with RAWNodesnodes over a Southbound API. It consumes data and information from the network and generates knowledge and wisdom to help steer the traffic optimally inside a recovery graph. </t> <figureanchor="FigCPF"> <name>RAWanchor="FigCPF" align="left" suppress-title="false" pn="figure-4"> <name slugifiedName="name-raw-nodes-centralized-routi">RAW Nodes (Centralized Routing Case)</name> <artwork align="center" name="" type=""alt="">alt="" pn="section-5.1-3.1"> DetNet Routing CPF CPF CPF CPF Southbound API _-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._- _-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._-._- ___ RAW ___ RAW ___ RAW ___ RAW __ / Node Node Node Node \ Ingress __/ / \ / \ \____Egress End __ / \ / .- -- . \ ___ End Node \ / \ / .-( ). \ / Node \_ RAW ___ RAW ___(Non-RAW Nodes)__ RAW _/ Node Node (___.______.____) Node </artwork> </figure><t><t indent="0" pn="section-5.1-4"> When a new flow is defined, the routing function uses its current knowledge of the network to build a new recovery graph between anIngressingress End System and anEgressegress End System for that flow; it indicates to the RAWNodesnodes where the PREOF and/or radio diversity and reliability operations may be actioned in the Network Plane. </t><ul> <li><ul bare="false" empty="false" indent="3" spacing="normal" pn="section-5.1-5"> <li pn="section-5.1-5.1"> The recovery graph may be strict, meaning that the DetNet forwarding sub-layer operations are enforcedend-to-end </li><li>end to end. </li> <li pn="section-5.1-5.2"> The recovery graph may be expressed loosely to enable traversing a non-RAW subnetwork as in <xreftarget='FigDN3'/>.target="FigDN3" format="default" sectionFormat="of" derivedContent="Figure 7"/>. In that case, RAW cannot leverage end-to-end DetNet and cannot provide latency guarantees. </li> </ul><t><t indent="0" pn="section-5.1-6"> The information that the orientation function reports to the routing functionincludesmay bea time-aggregated, e.g., statistical fashion,time aggregated (e.g., statistical), to match the longer-term operation of the routing function. Example information includesLink-Layerlink-layer metrics such asLinklink bandwidth (the medium speed depends dynamically on the mode of thephysical (PHY)PHY layer), number of flows (bandwidth that can be reserved for a flow depends on the number and size of flows sharing thespectrum)spectrum), and the average and mean squared deviation of availability and reliabilitymetrics, suchmetrics (such asPacket Delivery Ratio (PDR)PDR) over long periods of time. It may also report an aggregatedexpected transmission count (ETX),Expected Transmission Count (ETX) or a variation of it.</t><t></t> <t indent="0" pn="section-5.1-7"> Based on those metrics, the routing function installs the recovery graph with enough redundant forwarding solutions to ensure that the Network Plane can reliably deliver the packets within an SLA associated with the flows that it transports. The SLA defines end-to-end reliability and availability requirements, in which reliability may be expressed as a successful deliveryin-orderin order and within a bounded delay of at least one copy of a packet.</t><t></t> <t indent="0" pn="section-5.1-8"> Depending on the use case and the SLA, the recovery graph may comprise non-RAW segments, either interleaved inside the recovery graph(e.g.(e.g., overtunnels),tunnels) or all the way to theEgressegress EndNodenode (e.g., a server in the local wired domain). RAW observes theLower-Layer Linkslower-layer links between RAW nodes(typically,(typically radio links) and the end-to-endNetwork Layernetwork-layer operation to decide at all times which of the diversity schemes is actioned by which RAWNodes. </t><t>nodes. </t> <t indent="0" pn="section-5.1-9"> Once a recovery graph is established, per-segment and end-to-end reliability and availability statistics are periodically reported to the routing function to ensure that the SLA can bemet ormet; if not, thenhavethe recovery graph is recomputed. </t> </section><!--The RAW Network Plane --><section anchor="layers" numbered="true"toc="default"> <name>RAW vs.toc="include" removeInRFC="false" pn="section-5.2"> <name slugifiedName="name-raw-versus-upper-and-lower-">RAW Versus Upper and Lower Layers</name><t>RAW<t indent="0" pn="section-5.2-1">RAW builds on DetNet-provided features such as scheduling and shaping. In particular, RAW inherits the DetNet guarantees on end-to-end latency, which can be tuned to ensure that DetNet and RAW reliability mechanisms have no side effect on upper layers, e.g., on transport-layer packet recovery. RAW operations include possible rerouting, which in turn may affect the ordering of a burst of packets. RAW also inherits PREOF from DetNet, which can be used to reorder packets before delivery to the upper layers. As a result, DetNet in general and RAW in particular offer a smoother transport experience for the upper layers than the Internet atlargelarge, with ultra-low jitter and loss. </t><t><t indent="0" pn="section-5.2-2"> RAW improves the reliability of transmissions and the availability of the communicationresources,resources and should be seen as a dynamic optimization of the use of redundancy to maintainitreliability and availability metrics within certain boundaries. For instance,ARQ, whichARQ (which provides1-hopone-hop reliability through acknowledgements andretries,retries) and FEC codessuch(such as turbo codes which reduce thePER,PER) are typically operated atLayer-2Layer 2 andLayer-1Layer 1, respectively. In both cases, redundant transmissions improve the1-hopone-hop reliability at the expense of energy and latency, which are the resources that RAW must control. In order to achieve its goals, RAW may leverage the lower-layer operations by abstracting the concept and providing hints to the lower layers on the desiredoutcome, e.g.,outcome (e.g., in terms of reliability andtimeliness,timeliness), as opposed to performing the actual operations atLayer-3.Layer 3. </t><t><t indent="0" pn="section-5.2-3"> Guarantees such as bounded latency depend on the upper layers(Transport(transport orApplication)application) to provide the payload in volumes and at times that match the contract with the DetNet sub-layers and the layers below.ExcessAn excess of incoming traffic at the DetNetIngressingress may result in dropping or queueing ofpackets,packets and can entail loss, latency, orjitter, and therefore, violatejitter; this violates the guarantees that are provided inside the DetNet Network. </t><t><t indent="0" pn="section-5.2-4"> When the traffic from upper layers matches the expectation of the lower layers, RAW still depends on DetNet mechanisms and the lower layers to provide the timing and physical resource guarantees that are needed to match the traffic SLA. When the availability of the physical resource varies, RAW acts on the distribution of the traffic to leverage alternates within a finite set of potential resources. </t><t><t indent="0" pn="section-5.2-5"> The Operational Plane elements(Routing(routing and OAM control) may gather aggregated information from lower layers (e.g., information aboute.g.,linkquality, eitherquality), via measurement or communication with the lower layer. This information may be obtained from inside the device using specialized APIs (e.g., L2triggers),triggers) via monitoring and measurement protocols such asBFDBidirectional Forwarding Detection (BFD) <xreftarget="RFC5880"/>target="RFC5880" format="default" sectionFormat="of" derivedContent="RFC5880"/> andSTAMPSimple Two-way Active Measurement Protocol (STAMP) <xreftarget="RFC8762"/>,target="RFC8762" format="default" sectionFormat="of" derivedContent="RFC8762"/>, respectively, or via a control protocol exchange with the lower layervia, e.g.,(e.g., DLEP <xreftarget="RFC8175"/>.target="RFC8175" format="default" sectionFormat="of" derivedContent="DLEP"/>). It may then be processed and exported through OAM messaging or via a YANG datamodel,model and exposed to the Controller Plane. </t> </section><!--The RAW Network Plane --><section anchor="DetNet" numbered="true"toc="default"> <name>RAWtoc="include" removeInRFC="false" pn="section-5.3"> <name slugifiedName="name-raw-and-detnet">RAW and DetNet</name><t><t indent="0" pn="section-5.3-1"> RAW leverages the DetNetForwardingforwarding sub-layer and requires the support of OAM in DetNetTransit Nodestransit nodes (see Figure 3 of <xreftarget="RFC8655"/>)target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/>) for the dynamic acquisition of link capacity and state to maintain a strict RAWservice, end-to-end,service end to end over a DetNet Network. In turn, DetNet and thus RAW may benefit from/or leverage functionality such as that provided by TSN at the lower layers. </t><t><t indent="0" pn="section-5.3-2"> RAW extends DetNet to improve the protection against link errors such as transient flapping that are far more common in wireless links. Nevertheless, for the most part, the RAW methods arefor the most partapplicable to wired links as well, e.g., when energy savings are desirable and the available path diversity exceeds 1+1 linear redundancy. </t><t><t indent="0" pn="section-5.3-3"> RAW adds sub-layer functions that operate in the DetNet Operational Plane, which is part of the Network Plane. The RAW orientation function may run only in the DetNetEdge Nodes (Ingress Edge Nodeedge nodes (ingress edge node or End System), or it can also run in DetNetRelay Nodesrelay nodes when the RAW operations are distributed along the recovery graph. The RAW Service sub-layer includes the PLR, which decides the DetNetPathpath for the future packets of a flow along the DetNetPath,path, Maintenance End Points (MEPs) on edge nodes, and Maintenance Intermediate Points (MIPs) within. The MEPs trigger, and learn from, OAMobservations,observations and feed the PLR for its next decision. </t><t><t indent="0" pn="section-5.3-4"> As illustrated in <xreftarget='FigDN'/>,target="FigDN" format="default" sectionFormat="of" derivedContent="Figure 5"/>, RAW extends the DetNet Stack (see Figure 4 of <xreftarget="RFC8655"/>target="RFC8655" format="default" sectionFormat="of" derivedContent="DetNet-ARCH"/> and <xreftarget='FigLayers'/>)target="FigLayers" format="default" sectionFormat="of" derivedContent="Figure 3"/>) with additional functionality at the DetNet Service sub-layer for the actuation of PREOF based on the PLR decision. DetNet operates atLayer-3,Layer 3, leveraging abstractions of the lower layers and APIs that control those abstractions. For instance, DetNet already leverages lower layers for time-sensitive operations such as time synchronization and traffic shapers. As the performances of the radio layers are subject to rapid changes, RAW needs more dynamic gauges and knobs. To that effect, the LL API provides an abstraction to the DetNet layer that can be used to push reliability and timinghintshints, likesuggestsuggesting X retries (min, max) within a timewindow,window orsendsending unicast (one next hop) or multicast (for overhearing). In the other direction up the stack, the RAW PLR needs hints about the radio conditions such as L2 triggers (e.g., RSSI, LQI, or ETX) over all the wireless hops. </t><t><t indent="0" pn="section-5.3-5"> RAW uses various OAM functionalities at the different layers. For instance, the OAM function in the DetNet Service sub-layer may perform Active and/or Hybrid OAM to estimate the link and path availability,end-to-endeither end to end or limited to aSegment.segment. The RAW functions may be present in the Service sub-layer in DetNetEdgeedge andRelay Nodes.relay nodes. </t> <figureanchor="FigDN"> <name>RAW function placementanchor="FigDN" align="left" suppress-title="false" pn="figure-5"> <name slugifiedName="name-raw-function-placement-cent">RAW Function Placement (Centralized Routing Case)</name> <artwork align="left" name="" type=""alt="">alt="" pn="section-5.3-6.1"> +-----------------+ +-------------------+ | Routing | | OAM Control | +-----------------+ +-------------------+ Controller Plane +-+-+-+-+-+-+-+-+ Southbound Interface -+-+-+-+-+-+-+-+-+-+-+-+ Network Plane | Operational Plane . Data Plane | +-----------------+ . | Orientation | | +-----------------+ . | +-----------------+ +-------------------+ . | Point of Local | | OAM Maintenance | | |localRepair (PLR) | | End Point (MEP) | . +-----------------+ +-------------------+ | . | </artwork> </figure><t> There<t indent="0" pn="section-5.3-7">There are two main proposed models to deploy RAW andDetNet.DetNet: strict (<xref target="FigDN2" format="default" sectionFormat="of" derivedContent="Figure 6"/>) and loose (<xref target="FigDN3" format="default" sectionFormat="of" derivedContent="Figure 7"/>). In thefirst model (strict) (illustratedstrict model, illustrated in <xreftarget="FigDN2"/>),target="FigDN2" format="default" sectionFormat="of" derivedContent="Figure 6"/>, RAW operates over a continuous DetNetService end-to-endservice end to end between theIngressingress and theEgress Edge Nodesegress edge nodes or End Systems. </t><t> sIn<t indent="0" pn="section-5.3-8"> In thesecond model (loose),loose model, illustrated in <xref target="FigDN3" format="default" sectionFormat="of" derivedContent="Figure 7"/>, RAW may traverse a section of the network that is not serviced by DetNet. RAW/OAM may observe the end-to-end traffic and make the best of the available resources, but it may not expect the DetNet guarantees over all paths. For instance, the packets between two wireless entities may be relayed over a wired infrastructure, in which case RAW observes and controls the transmission over the wireless first and last hops, as well as end-to-end metrics such as latency, jitter, and delivery ratio. This operation is loose since the structure and properties of the wired infrastructure areignored,ignored and may be either controlled by other means such asDetNet/TSN,DetNet/TSN or neglected in the face of the wireless hops. </t><t><t indent="0" pn="section-5.3-9"> A minimalForwardingforwarding sub-layer service is provided at all DetNetNodesnodes to ensure that the OAM information flows. DetNetRelay Nodesrelay nodes may or may not support RAW services, whereas the DetNetEdge Nodesedge nodes are required to support RAW in any case. DetNet guarantees, such as bounded latency, are providedend-to-end.end to end. RAW extends the DetNet Service sub-layer to optimize the use of resources. </t> <figureanchor="FigDN2"> <name>(Strict) RAWanchor="FigDN2" align="left" suppress-title="false" pn="figure-6"> <name slugifiedName="name-raw-over-detnet-strict-mode">RAW overDetNet</name>DetNet (Strict Model)</name> <artwork align="left" name="" type=""alt="">alt="" pn="section-5.3-10.1"> --------------------FlowDirection---------------------------------->Direction----------------------------------> +---------+ | RAW | | Control | +---------+ +---------+ +---------+ | RAW + | | RAW + | | RAW + | | DetNet | | DetNet | | DetNet | | Service | | Service | | Service | +---------+---------------------------+---------+--------+---------+ | DetNet | | Forwarding | +------------------------------------------------------------------+ Ingress Transit Relay Egress Edge ... Nodes ... Nodes ... Edge Node Node <------------------End-to-End DetNetService----------------------->Service-----------------------> </artwork> </figure><t> In<t indent="0" pn="section-5.3-11">In thesecondloose model(loose), illustrated(illustrated in <xreftarget="FigDN3"/>,target="FigDN3" format="default" sectionFormat="of" derivedContent="Figure 7"/>), RAW operates over a partial DetNetServiceservice where typically only theIngressingress and theEgressegress End Systems support RAW. The DetNetDomaindomain may extend beyond theIngress Node,ingress node, or there may be a DetNet domain starting at anIngress Edge Nodeingress edge node at the first hop after the End System. </t><t><t indent="0" pn="section-5.3-12"> In the loose model, RAW cannot observe the hops in the network, and the path beyond the first hop is opaque; RAW can still observe the end-to-end behavior and useLayer-3Layer 3 measurements to decide whether to replicate a packet and select the first-hop interface(s). </t> <figureanchor="FigDN3"> <name>Loose RAW</name>anchor="FigDN3" align="left" suppress-title="false" pn="figure-7"> <name slugifiedName="name-raw-over-detnet-loose-model">RAW over DetNet (Loose Model)</name> <artwork align="left" name="" type=""alt="">alt="" pn="section-5.3-13.1"> --------------------FlowDirection---------------------------------->Direction----------------------------------> +---------+ | RAW | | Control | +---------+ +---------+ +---------+ | RAW + | | DetNet | | RAW + | | DetNet | | Only | | DetNet | | Service | | Service | | Service | +---------+----------------------+---+ +---+---------+ | DetNet |_______________| DetNet | | Forwarding _______________ Forwarding | +------------------------------------+ +-------------+ Ingress Transit Relay Tunnel Egress End ... Nodes ... Nodes ... ... End System System <---------------Partitioned DetNetService------------------------->Service-------------------------> </artwork> </figure> </section><!-- RAW and DetNet --> <!-- 1111111111111 --></section><!-- The RAW Conceptual Model --><section anchor="control" numbered="true"toc="default"> <name>Thetoc="include" removeInRFC="false" pn="section-6"> <name slugifiedName="name-the-raw-control-loop">The RAW Control Loop</name><t><t indent="0" pn="section-6-1"> The RAWArchitecturearchitecture is based on an abstract OODALooploop that controls the operation of aRecovery Graph.recovery graph. The generic conceptinvolves:involves the following: </t><ol> <li> Operational<ol indent="adaptive" spacing="normal" start="1" type="1" pn="section-6-2"> <li pn="section-6-2.1" derivedCounter="1.">Operational Plane measurement protocolsforallow OAM to observe (like the firstO"O" inOODA)"OODA") some or all hops along a recovery graph as well as the end-to-end packet delivery. </li><li><li pn="section-6-2.2" derivedCounter="2."> The DetNet Controller Planeestablishestablishes primary and protection paths for use by the RAW Network Plane. The orientation function reports data and information such as link statistics to be used by the routing function to compute, install, and maintain the recovery graphs. The routing function may also generate intelligence such as a trained model for link quality prediction, which in turn can be used by the orientation function (like the secondO"O" inOODA)"OODA") to influence thePathpath selection by the PLR within the RAW OODA loop. </li><li> A<li pn="section-6-2.3" derivedCounter="3.">A PLR operates at the DetNet Service sub-layer and hosts the decision function (like theD"D" inOODA) of"OODA"). The decision function determines which DetNetPaths to usepaths will be used forthefuture packets that are routed within the recovery graph. </li><li> Service<li pn="section-6-2.4" derivedCounter="4.">Service protection actionsthatare actuated or triggered over the LL API by the PLR to increase the reliability of the end-to-end transmissions. The RAW architecture also covers in-situ signaling that is embedded within live user traffic <xreftarget="RFC9378"/>, e.g.,target="RFC9378" format="default" sectionFormat="of" derivedContent="RFC9378"/> (e.g., viaOAM,OAM) when the decision is acted (like theA"A" inOODA)"OODA") upon by a node that is downstream in the recovery graph from the PLR. </li> </ol><t> The<t indent="0" pn="section-6-3">The overall OODALooploop optimizes the use of redundancy to achieve the required reliability and availability SLO(s) while minimizing the use of constrained resources such as spectrum and battery. </t> <section anchor="timescale" numbered="true"toc="default"> <name>Routing Time-Scale vs.toc="include" removeInRFC="false" pn="section-6.1"> <name slugifiedName="name-routing-timescale-versus-fo">Routing Timescale Versus ForwardingTime-Scale</name> <t>Timescale</name> <t indent="0" pn="section-6.1-1"> With DetNet, the Controller Plane Function (CPF) handles the routing computation and maintenance. With RAW, the routing operation is segregated from the RAWControl Loop,control loop, so it may reside in the ControllerPlanePlane, whereas the control loop itself happens in the Network Plane. To achieve RAW capabilities, the routing operation is extended to generate the information required by the orientation function in the loop.TheFor example, the routing functionmay, e.g.,may propose DetNetPathspaths to be used as a reflex action in response to networkevents,events or provide an aggregated history that the orientation function can use to make a decision. </t><t><t indent="0" pn="section-6.1-2"> In a wireless mesh, the path to a routing function located in thecontroller planeController Plane can be expensive and slow, possibly going across the whole mesh and back. Reachingtothe Controller Plane can also be slow inregardsregard to the speed of events that affect the forwarding operation in the Network Plane at the radio layer. Note that a distributed routing protocol may also take time and consume excessive wireless resources to reconverge to a new optimized state.</t><t></t> <t indent="0" pn="section-6.1-3"> As a result, the DetNet routing function is not expected to be aware of andtoreact to very transient changes. The abstraction of a link at the routing level is expected to use statistical metrics that aggregate the behavior of a link over long periods oftime,time and represent its properties as shades of gray as opposed to numerical values such as a link qualityindicator,indicator or a Boolean value for either up or down.</t><t></t> <t indent="0" pn="section-6.1-4"> The interaction between the network nodes and the routing function is handled by the orientation function, whichbuildsreports to the routing function and sends control information in a digested form back to the RAWnode,node to be used inside a forwarding control loop for traffic steering.</t><t> <xref target="Figcontrol"/></t> <t indent="0" pn="section-6.1-5"> <xref target="Figcontrol" format="default" sectionFormat="of" derivedContent="Figure 8"/> illustrates a Network Plane recovery graph with links P-Q and N-E flapping, possibly in a transient fashion due toashort-terminterferences,interferences and possibly for a longertime, e.g.,time (e.g., due to obstacles between the sender and the receiver or hardwarefailures.failures). In order to maintain a received redundancy around a valueof, say, 2,of 2 (for instance), RAW may leverage a higher ARQ on these hops if the overall latency permits the extradelay,delay or enable alternate paths between ingress I and egress E. For instance, RAW may enable protection path I==>==> F==>==> N==>==> Q==>==> M==>==> R==>==> E that routes around both issues and provides some degree of spatial diversity with protection path I==>==> A==>==> B==>==> C==>==> D==>==> E. </t> <figureanchor="Figcontrol"> <name>Time-Scales</name>anchor="Figcontrol" align="left" suppress-title="false" pn="figure-8"> <name slugifiedName="name-timescales">Timescales</name> <artwork align="center" name="" type=""alt=""> <![CDATA[alt="" pn="section-6.1-6.1"> +----------------+ | DetNet | | Routing | +----------------+ ^ | Slow | Controller Plane _-._-._-._-._-._-. | ._-._-._-._-._-._-._-._-._-._-._-._- _-._-._-._-._-._-._-. | _-._-._-._-._-._-._-._-._-._-._-._- | Network Plane Expensive | __...--- | ----.._. .( | )-._ ( v ). ( A--------B---C----D ) _ - / \ / \ --._ ( I---F--------N--***-- E - -_ \ / / ) ( P--***---Q----M---R . _ )- ._ -<------<------ Fast------->-------> ) ( -._ .- (_.___.._____________.____.._ __-____) *** = flapping at this time]]></artwork> </figure><t><t indent="0" pn="section-6.1-7"> In the case of wireless, the changes that affect the forwarding decision can happen frequently and often for shortdurations, e.g.,durations. An example of this is a mobile object that moves between a transmitter and areceiver,receiver and cancels theline of sightline-of-sight transmission for a fewseconds, or, aseconds. Another example is radar that measures the depth of a pool using the ISMband,band and interferes on a particular channel for a split second. </t><t> There<t indent="0" pn="section-6.1-8"> Thus, there isthusa desire to separate the long-term computation of the route and the short-term forwarding decision. In that model, the routing operation computes a recovery graph that enables multipleUnequal Cost Multi-PathUnequal-Cost Multipath (UCMP) forwarding solutions along so-called protectionpaths,paths and leaves it to the Network Plane to make the short-term decision of which of these possibilities should be used for which upcoming packets/and flows. </t><t><t indent="0" pn="section-6.1-9"> In the context of Traffic Engineering (TE), an alternate path can be used upon the detection of a failure in the main path, e.g., using OAM in Multiprotocol Label Switching - Transport Profile (MPLS-TP) or BFD over a collection of Software-Defined Wide Area Network (SD-WAN) tunnels. </t><t><t indent="0" pn="section-6.1-10"> RAW formalizes a forwardingtime-scaletimescale that may be order(s) of magnitude shorter than the Controller Plane routingtime-scale,timescale and separates the protocols and metrics that are used at both scales. Routing can operate on long-term statistics such as delivery ratio over minutes to hours, but as a firstapproximationapproximation, it can ignore the cause of transient losses. On the other hand, the RAW forwarding decision is made at the scale of a burst ofpackets,packets and uses information that must be pertinent at the present time for the current transmission(s). </t></section > <!--Routing time-scale vs. Forwarding time-scale--></section> <section anchor="ooda" numbered="true"toc="default"> <name>OODAtoc="include" removeInRFC="false" pn="section-6.2"> <name slugifiedName="name-ooda-loop">OODA Loop</name><t><t indent="0" pn="section-6.2-1"> The RAWArchitecturearchitecture applies the generic OODA model to continuously optimize the spectrum and energy used to forward packets within a recovery graph, instantiating the OODA steps as follows: </t><dl> <dt>Observe:</dt><dd><dl indent="3" newline="false" spacing="normal" pn="section-6.2-2"> <dt pn="section-6.2-2.1">Observe:</dt> <dd pn="section-6.2-2.2"> Network Plane measurements, including protocols for OAM,to Observeobserve the local state of the links and some or all hops along a recovery graph as well as the end-to-end packet delivery (see more in <xreftarget = "aom"/>).target="aom" format="default" sectionFormat="of" derivedContent="Section 6.3"/>). Information can also be provided by lower-layer interfaces such asDLEP;DLEP. </dd><dt>Orient:</dt><dd><dt pn="section-6.2-2.3">Orient:</dt> <dd pn="section-6.2-2.4"> The orientationfunction, whichfunction reports data and information such as the linkstatistics,statistics and leverages offline-computed wisdom and knowledge toOrientorient the PLR for its forwarding decision (see more in <xreftarget = "pce" />);target="pce" format="default" sectionFormat="of" derivedContent="Section 6.4"/>). </dd><dt>Decide:</dt><dd> A<dt pn="section-6.2-2.5">Decide:</dt> <dd pn="section-6.2-2.6">A local PLRthatdecides which DetNetPathpath to use forthefuture packet(s) that are routed along the recovery graph (see more in <xreftarget = "PLRpce" />);target="PLRpce" format="default" sectionFormat="of" derivedContent="Section 6.5"/>). </dd><dt>Act:</dt><dd> PREOF<dt pn="section-6.2-2.7">Act:</dt> <dd pn="section-6.2-2.8">PREOF Data Plane actions are controlled by the PLR over the LL API to increase the reliability of the end-to-end transmission. The RAW architecture also covers in-situ signaling when the decision isActedacted by a node that is down the recovery graph from the PLR (see more in <xreftarget = "reliability" />).target="reliability" format="default" sectionFormat="of" derivedContent="Section 6.6"/>). </dd> </dl> <figureanchor="oodaloop"> <name>Theanchor="oodaloop" align="left" suppress-title="false" pn="figure-9"> <name slugifiedName="name-the-raw-ooda-loop">The RAW OODA Loop</name> <artwork align="center" name="" type=""alt=""> <![CDATA[ +------->alt="" pn="section-6.2-3.1"> +-------> Orientation ---------+ | reflex actions | | pre-trained model | | | ...................................... | | | Service sub-layer | | v Observe (OAM) Decide (PLR) ^ | | | | | +------- Act (LL API)<--------+ ]]></artwork><--------+ </artwork> </figure><t><t indent="0" pn="section-6.2-4"> The overall OODALooploop optimizes the use of redundancy to achieve the required reliability and availability Service Level Agreement (SLA) while minimizing the use of constrained resources such as spectrum and battery. </t></section > <!-- A OODA Loop --></section> <section anchor="aom" numbered="true"toc="default"> <name>Observe: Thetoc="include" removeInRFC="false" pn="section-6.3"> <name slugifiedName="name-observe-raw-oam">Observe: RAW OAM</name><t></name> <t indent="0" pn="section-6.3-1"> The RAWIn-situin-situ OAM operation in the Network Plane may observe either a full recovery graph or the DetNetPathpath that is being used at this time. As packets may be load balanced, replicated, eliminated,and / orand/or fragmented for Network Coding FEC, the RAWIn-situin-situ operation needs to be able to signal which operation occurred to an individual packet. </t><t><t indent="0" pn="section-6.3-2"> Active RAW OAM may be needed to observe the unused segments and evaluate the desirability of a rerouting decision. </t><t><t indent="0" pn="section-6.3-3"> Finally, the RAW Service sub-layer Service Assurance may observe the individual PREOF operation of a DetNetRelay Noderelay node to ensure that it is conforming; this might require injecting an OAM packet at an upstream point inside the recovery graph and extracting that packet at another point downstream before it reaches the egress.</t><t></t> <t indent="0" pn="section-6.3-4"> This observation feeds the RAW PLR that makes the decision on which path is used at which RAWNode,node, for one packet or a small continuous series of packets. </t><t><t indent="0" pn="section-6.3-5"> In the case ofEnd-to-End Protectionend-to-end protection in aWireless Mesh,wireless mesh, the recovery graph is strict and congruent with the path so all links are observed. </t><t><t indent="0" pn="section-6.3-6"> Conversely, in the case of Radio Access Protection, illustrated in <xreftarget="Figranp2"/>,target="Figranp2" format="default" sectionFormat="of" derivedContent="Figure 10"/>, the recovery graph isLooseloose and only the first hop is observed; the rest of the path is abstracted and considered infinitely reliable. The loss of a packet is attributed to the first-hop Radio Access Network (RAN), even if a particular loss effectively happens farther down the path. In that case, RAW enables technology diversity (e.g., Wi-Fi and 5G), which in turn improves the diversity in spectrum usage. </t> <figureanchor="Figranp2"> <name>Observedanchor="Figranp2" align="left" suppress-title="false" pn="figure-10"> <name slugifiedName="name-observed-links-in-radio-acc">Observed Links in Radio Access Protection</name> <artwork align="center" name="" type=""alt=""> <![CDATA[alt="" pn="section-6.3-7.1"> Opaque to OAM<----------------------------><----------------------------> .- .. - .. RAN 1 --------( ).__ +-------+ / ( ). +------+ |Ingress|- __________Tunnel_______________|Egress| | End |------ RAN 2 --_______________________________ End | |System |- ( ) |System| +-------+ \ ( ). +------+ RAN n ----( ) (_______...___.__...____....__..)<-------L2------><-------L2------> Observed by OAM<----------------------L3-----------------------> ]]></artwork><----------------------L3-----------------------> </artwork> </figure><t><t indent="0" pn="section-6.3-8"> TheLinkslinks that are not observed by OAM are opaque to it, meaning that the OAM information is carried across and possibly echoed as data, but there is no information captured in intermediate nodes. In the example above, theTunneltunnel underlay is opaque and not controlled by RAW;still thestill, RAW OAM measures the end-to-end latency and delivery ratio for packets sent via RAN 1, RAN 2, and RAN 3, and determines whether a packet should be sent over either access link or a collection of those access links. </t> </section><!-- Observe: The RAW OAM --><section anchor="pce" numbered="true"toc="default"> <name>Orient:toc="include" removeInRFC="false" pn="section-6.4"> <name slugifiedName="name-orient-the-raw-extended-det">Orient: TheRAW-extendedRAW-Extended DetNet Operational Plane</name><t><t indent="0" pn="section-6.4-1"> RAW separates the longtime-scaletimescale at which a recovery graph is computed andinstalled,installed from the shorttime-scaletimescale at which the forwarding decision is taken for one orfora few packets (see <xreftarget="timescale"/>)target="timescale" format="default" sectionFormat="of" derivedContent="Section 6.1"/>) that experience the same path until the network conditions evolve and another path is selected within the same recovery graph. </t><t><t indent="0" pn="section-6.4-2"> The recovery graph computation is out of scope, but RAW expects that the CPF that installs the recovery graph also provides related knowledge in the form of metadata about the links, segments, and possible DetNetPaths.paths. That metadata can be a pre-digested statisticalmodel,model and may include prediction of future flaps and packet loss, as well as recommended actions when that happens. </t><t><t indent="0" pn="section-6.4-3"> The metadata may include: </t><ul> <li><ul bare="false" empty="false" indent="3" spacing="normal" pn="section-6.4-4"> <li pn="section-6.4-4.1"> A set ofPre-Determinedpre-determined DetNetPathspaths that are prepared to match expected link-degradation profiles, so the DetNetRelay Nodesrelay nodes can take reflex rerouting actions when facing a degradation that matches one such profile; and </li><li> Link-Quality Statistics<li pn="section-6.4-4.2"> Link-quality statistics history and pre-trainedmodels, e.g.,models (e.g., to predict the short-term variation of quality of the links in a recoverygraph.graph). </li> </ul><t><t indent="0" pn="section-6.4-5"> The recovery graph is installed with measurable objectives that are computed by the CPF to achieve the RAW SLA. The objectives can be expressed as any of the maximum number of packets lost in a row, bounded latency, maximal jitter, maximum number of interleaved out-of-order packets, average number of copies received at the elimination point, and maximal delay between the first and the last received copy of the same packet. </t> </section><!-- Orient: The Path Computation Engine --><section anchor="PLRpce" numbered="true"toc="default"> <name>Decide:toc="include" removeInRFC="false" pn="section-6.5"> <name slugifiedName="name-decide-the-point-of-local-r">Decide: The Point of Local Repair</name><t><t indent="0" pn="section-6.5-1"> The RAW OODALooploop operates at the path selectiontime-scaletimescale to provide agilityvs.versus the brute-force approach of flooding the whole recovery graph.The OODA Loop controls, withinWithin the redundant solutions that are proposed by the routing function,whichthe OODA loop controls what is used for each packetto provideand provides aReliablereliable andAvailableavailable service while minimizing the waste of constrained resources.</t><t></t> <t indent="0" pn="section-6.5-2"> To that effect, RAW defines the Point of Local Repair (PLR), which performs rapid local adjustments of the forwarding tables within the path diversity that is available in that in the recovery graph. The PLR enables exploitation of the richer forwarding capabilities at a fastertime-scaletimescale over a portion of the recovery graph, in either a loose or a strict fashion. </t><t><t indent="0" pn="section-6.5-3"> The PLR operates on metrics that evolvefaster, but thatquickly and need to be advertised at a fast ratebut(but only locally, within the recoverygraph,graph), and the PLR reactsonto the metric updates by changing the DetNet path in use for the affected flows. </t><t><t indent="0" pn="section-6.5-4"> The rapid changes in the forwarding decisions are made and contained within the scope of a recoverygraphgraph, and the actions of the PLR are not signaled outside the recovery graph. This is as opposed to the routing function that must observe the whole network and optimize all the recovery graphs globally, which can only be done at a slow pace andusingwith long-term statistical metrics, as presented in <xreftarget="PCEPLRtable"/>.target="PCEPLRtable" format="default" sectionFormat="of" derivedContent="Table 1"/>. </t> <tableanchor="PCEPLRtable"><name>Centralizedanchor="PCEPLRtable" align="center" pn="table-1"> <name slugifiedName="name-centralized-decision-versus">Centralized Decisionvs.Versus PLR</name> <thead> <tr><th> </th><thalign='center'> Controller Plane </th>align="left" colspan="1" rowspan="1"/> <thalign='center'> PLR </th>align="left" colspan="1" rowspan="1">Controller Plane</th> <th align="left" colspan="1" rowspan="1">PLR</th> </tr></thead><tbody> <tr><td>Communication </td></thead> <tbody> <tr> <th align="left" colspan="1" rowspan="1">Communication</th> <tdalign='center'>Slow,align="left" colspan="1" rowspan="1">Slow, distributed</td> <tdalign='center'>Fast,align="left" colspan="1" rowspan="1">Fast, local</td> </tr><tr><td>Time-Scale (order)</td><tr> <th align="left" colspan="1" rowspan="1">Timescale (order)</th> <tdalign='center'>Pathalign="left" colspan="1" rowspan="1">Path computation + round trip, milliseconds to seconds</td> <tdalign='center'>Lookupalign="left" colspan="1" rowspan="1">Lookup + protection switch, micro to milliseconds</td> </tr><tr><td>Network Size</td><tr> <th align="left" colspan="1" rowspan="1">Network Size</th> <tdalign='center'>Large,align="left" colspan="1" rowspan="1">Large, many recovery graphs to optimize globally</td> <tdalign='center'>Small,align="left" colspan="1" rowspan="1">Small, limited set of protection paths</td> </tr><tr><td>Considered Metrics</td><tr> <th align="left" colspan="1" rowspan="1">Considered Metrics</th> <tdalign='center'>Averaged,align="left" colspan="1" rowspan="1">Averaged, statistical, shade of grey</td> <tdalign='center'>Instantaneousalign="left" colspan="1" rowspan="1">Instantaneous values / boolean condition</td> </tr> </tbody> </table><t><t indent="0" pn="section-6.5-6"> The PLR sits in the DetNetForwardingforwarding sub-layer ofEdgeedge andRelay Nodes.relay nodes. The PLR operates on the packet flow, learning the recovery graph and path-selection information from thepacket,packet and possibly making a local decision and retagging the packet to indicate so. On the other hand, the PLR interacts with the lower layers (through triggers and DLEP) and with its peers (through OAM) to obtain up-to-date information about its links and the quality of the overall recovery graph, respectively, as illustrated in <xreftarget="Figlearn"/>.target="Figlearn" format="default" sectionFormat="of" derivedContent="Figure 11"/>. </t> <figureanchor="Figlearn"> <name>PLRanchor="Figlearn" align="left" suppress-title="false" pn="figure-11"> <name slugifiedName="name-plr-conceptual-interfaces">PLR Conceptual Interfaces</name> <artwork align="center" name="" type=""alt=""><![CDATA[alt="" pn="section-6.5-7.1"> |packetPacket | going down the | stack +==========v==========+=====================+===================+ |(In-situ OAM + iCTRL)| (L2Triggers,triggers, DLEP) | (Hybrid OAM) | +==========v==========+=====================+===================+ | Learn from | | Learn from | | packet tagging>> Maintain<< end-to-end | +----------v----------+ Forwarding | OAM packets | | Forwarding decision<< State +---------^---------| +----------v----------+ | Enrich or | + RetagPacketpacket | Learn abstracted> Regenerate> regenerate | | andForwardforward | metrics aboutLinkslinks | OAM packets | +..........v..........+..........^..........+........^.v........+ | Lower layers | +..........v.....................^...................^.v........+frameFrame | sent Frame | L2Ackack Active | | OAM over | wirelessInin |Inin and | | out v | | v]]></artwork></artwork> </figure> </section><!--PCE vs. PLR--> <!-- 11111111111111111 --><section anchor="reliability" numbered="true"toc="default"> <name>Act:toc="include" removeInRFC="false" pn="section-6.6"> <name slugifiedName="name-act-detnet-path-selection-a">Act: DetNet Path Selection and Reliability Functions</name><t><t indent="0" pn="section-6.6-1"> The main action by the PLR is the swapping of the DetNetPathpath within the recovery graph for the future packets. The candidate DetNetPathspaths represent different energy and spectrumprofiles,profiles and provide protection against different failures. </t><t>The<t indent="0" pn="section-6.6-2">The LL API enriches the DetNet protection services (PREOF) withpotentialthe possibility to interact withlower-layerlower-layer, one-hop reliability functions that are more typicaltowith wireless links thanwired,with wired ones, including ARQ, FEC, and other techniques such as overhearing and constructive interferences. Because RAW may be leveraged on wiredlinks, e.g.,links (e.g., to savepower,power), it is not expected that all lower layers support all those capabilities. </t><t><t indent="0" pn="section-6.6-3"> RAW provides hints to the lower-layer services on the desired outcome, and the lower layer acts on those hints to provide the best approximation of that outcome, e.g., a level of reliability for one-hop transmission within a bounded budget of time and/or energy. Thus, the LL API makes possible cross-layer optimization for reliability depending on the actual abstraction provided. That is, some reliability functions are controlled fromLayer-3Layer 3 using an abstract interface, while they are really operated at the lower layers. </t><t><t indent="0" pn="section-6.6-4"> The RAWPath Selectionpath selection can be implemented in both centralized and distributed approaches. In the centralized approach, the PLR may obtain a set of pre-computed DetNet paths matching a set of expectedfailures,failures and apply the appropriate DetNet paths for the current state of the wireless links. In the distributed approach, the signaling in the packet may be more abstract than an explicitPath,path, and the PLR decision might be revised along the selected DetNetPathpath based on a better knowledge of the rest of the way. </t><t><t indent="0" pn="section-6.6-5"> The dynamic DetNetPathpath selection in RAW avoids the waste of critical resources such as spectrum and energy while providing for the assured SLA, e.g., by rerouting and/or adding redundancy only when a loss spike is observed. </t> </section><!-- Act: The reliability Functions--></section><!-- The RAW Control Loop --> <!-- 000000000000000000000 --><section anchor="SecurityConsiderations" numbered="true"toc="default"> <name>Securitytoc="include" removeInRFC="false" pn="section-7"> <name slugifiedName="name-security-considerations">Security Considerations</name> <section numbered="true"toc="default"> <name>Collocated Denial of Servicetoc="include" removeInRFC="false" pn="section-7.1"> <name slugifiedName="name-collocated-denial-of-servic">Collocated Denial-of-Service Attacks</name><t><t indent="0" pn="section-7.1-1"> RAW leverages diversity (e.g., spatial and time diversity, coding diversity, and frequency diversity), possibly using heterogeneous wired and wireless networking technologies over different physical paths, to increasethereliability and availability in the face of unpredictable conditions. While this is not done specifically to defeat an attacker, the amount of diversity used in RAW defeats possible attacks that would impact a particular technology or a specific path. </t><t><t indent="0" pn="section-7.1-2"> Physical actions by a collocated attacker such as a radio interference may still lower the reliability of an end-to-end RAW transmission by blocking one segment or one possible path.ButHowever, if an alternate path with diverse frequency, location, and/ortechnology,technology is available, then RAW adapts by rerouting the impacted traffic over the preferred alternates, which defeats the attack after a limited period of lower reliability. Then again, the security benefit is aside-effectside effect of an action that is taken regardless of whether or not the source of the issue is voluntary (anattack) or not.attack). </t></section><!-- Collocated Denial of Service Attacks --></section> <section numbered="true"toc="default"> <name>Layer-2 encryption</name> <t>toc="include" removeInRFC="false" pn="section-7.2"> <name slugifiedName="name-layer-2-encryption">Layer 2 Encryption</name> <t indent="0" pn="section-7.2-1"> Radio networks typically encrypt at theMACMedia Access Control (MAC) layer to protect the transmission. If the encryption isper-pairper pair of peers, then certain RAW operations like promiscuous overhearing become impractical. </t></section><!-- Layer-2 encryption --></section> <section numbered="true"toc="default"> <name>Forcedtoc="include" removeInRFC="false" pn="section-7.3"> <name slugifiedName="name-forced-access">Forced Access</name><t><t indent="0" pn="section-7.3-1"> A RAW policymaytypicallyselectselects the cheapest collection of links that matches the requested SLA, e.g., use free Wi-Fivs.versus paid 3GPP access. By defeating the cheap connectivity (e.g., PHY-layer interference) the attacker can force an End System to use the paid access and increase the cost of the transmission for the user. </t><t><t indent="0" pn="section-7.3-2"> Similar attacks may also be used to deplete resources in lower-power nodes by forcing additional transmissions for FEC and ARQ, and attack metrics such as battery life of the nodes. By affecting the transmissions and the associated routing metrics in one area, an attacker may force the traffic and cause congestion along a remote path, thus reducing the overall throughput of the network. </t></section><!-- Forced Access --> <!-- 111111111111111111111 --> </section> <!--Security Considerations--> <!-- 000000000000000000000 --></section> </section> <section numbered="true"toc="default"> <name>IANAtoc="include" removeInRFC="false" pn="section-8"> <name slugifiedName="name-iana-considerations">IANA Considerations</name><t>This<t indent="0" pn="section-8-1">This document has no IANAactions. </t> </section> <!--IANA Considerations--> <!-- 000000000000000000000 --> <section numbered="true" toc="default"> <name>Contributors</name> <t>The editor wishes to thank the following individuals for their contributions to the text and ideas exposed in this document: </t> <dl> <dt>Lou Berger:</dt><dd>LabN Consulting, L.L.C, lberger@labn.net</dd> <!--dt>Janos Farkas:</dt><dd>Erisson, Janos.Farkas@ericsson.com</dd--> <dt>Xavi Vilajosana:</dt><dd>Wireless Networks Research Lab, Universitat Oberta de Catalunya, xvilajosana@gmail.com</dd> <dt>Geogios Papadopolous:</dt><dd>IMT Atlantique , georgios.papadopoulos@imt-atlantique.fr</dd> <dt>Remous-Aris Koutsiamanis:</dt><dd>IMT Atlantique, remous-aris.koutsiamanis@imt-atlantique.fr </dd> <dt>Rex Buddenberg:</dt><dd>retired, buddenbergr@gmail.com</dd> <dt>Greg Mirsky:</dt><dd>Ericsson, gregimirsky@gmail.com</dd> </dl> </section> <!--ConTributors--> <!-- 000000000000000000000 --> <section><name>Acknowledgments</name> <t>This architecture could never have been completed without the support and recommendations from the DetNet Chairs Janos Farkas and Lou Berger, and Dave Black, the DetNet Tech Advisor. Many thanks to all of you. </t> <t>The authors wish to thank Ketan Talaulikar, as well as Balazs Varga, Dave Cavalcanti, Don Fedyk, Nicolas Montavont, and Fabrice Theoleyre for their in-depth reviews during the development of this document. </t> <t>The authors wish to thank Acee Lindem, Eva Schooler, Rich Salz, Wesley Eddy, Behcet Sarikaya, Brian Haberman, Gorry Fairhurst, Eric Vyncke, Erik Kline, Roman Danyliw, and Dave Thaler, for their reviews and comments during the IETF Last Call / IESG review cycle. </t> <t> Special thanks for Mohamed Boucadair, Giuseppe Fioccola, and Benoit Claise, for their help dealing with OAM technologies. </t>actions.</t> </section><!-- Acknowledgments --> <!-- 000000000000000000000 --></middle> <back> <displayreferencetarget="I-D.ietf-raw-technologies"target="RFC9913" to="RAW-TECHNOS"/> <displayreferencetarget="I-D.ietf-raw-use-cases"target="RFC9450" to="RAW-USE-CASES"/> <displayreference target="RFC1122"to="INT-ARCHI"/>to="INT-ARCH"/> <displayreference target="RFC9522" to="TE"/> <displayreference target="RFC8175" to="DLEP"/> <displayreference target="RFC7490" to="RLFA-FRR"/> <displayreference target="RFC5714" to="FRR"/> <displayreference target="RFC8938" to="DetNet-DP"/><!--displayreference target="RFC9016" to="DetNet-Flow"/--><displayreference target="RFC8655"to="DetNet-ARCHI"/>to="DetNet-ARCH"/> <displayreference target="RFC9030"to="6TiSCH-ARCHI"/>to="6TiSCH-ARCH"/> <displayreference target="RFC9551" to="DetNet-OAM"/><references> <name>References</name> <references> <name>Normative<displayreference target="RFC9938" to="DetNet-PLANE"/> <references pn="section-9"> <name slugifiedName="name-references">References</name> <references pn="section-9.1"> <name slugifiedName="name-normative-references">Normative References</name><xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-raw-technologies.xml"/> <!-- Reliable<reference anchor="RFC8655" target="https://www.rfc-editor.org/info/rfc8655" quoteTitle="true" derivedAnchor="DetNet-ARCH"> <front> <title>Deterministic Networking Architecture</title> <author fullname="N. Finn" initials="N." surname="Finn"/> <author fullname="P. Thubert" initials="P." surname="Thubert"/> <author fullname="B. Varga" initials="B." surname="Varga"/> <author fullname="J. Farkas" initials="J." surname="Farkas"/> <date month="October" year="2019"/> <abstract> <t indent="0">This document provides the overall architecture for Deterministic Networking (DetNet), which provides a capability to carry specified unicast or multicast data flows for real-time applications with extremely low data loss rates andAvailable Wireless Technologies -->bounded latency within a network domain. Techniques used include 1) reserving data-plane resources for individual (or aggregated) DetNet flows in some or all of the intermediate nodes along the path of the flow, 2) providing explicit routes for DetNet flows that do not immediately change with the network topology, and 3) distributing data from DetNet flow packets over time and/or space to ensure delivery of each packet's data in spite of the loss of a path. DetNet operates at the IP layer and delivers service over lower-layer technologies such as MPLS and Time- Sensitive Networking (TSN) as defined by IEEE 802.1.</t> </abstract> </front> <seriesInfo name="RFC" value="8655"/> <seriesInfo name="DOI" value="10.17487/RFC8655"/> </reference> <referenceanchor="TSN" target="https://1.ieee802.org/tsn/">anchor="RFC9551" target="https://www.rfc-editor.org/info/rfc9551" quoteTitle="true" derivedAnchor="DetNet-OAM"> <front><title>Time-Sensitive<title>Framework of Operations, Administration, and Maintenance (OAM) for Deterministic Networking(TSN)</title> <author> <organization>IEEE</organization>(DetNet)</title> <author fullname="G. Mirsky" initials="G." surname="Mirsky"/> <author fullname="F. Theoleyre" initials="F." surname="Theoleyre"/> <author fullname="G. Papadopoulos" initials="G." surname="Papadopoulos"/> <author fullname="CJ. Bernardos" initials="CJ." surname="Bernardos"/> <author fullname="B. Varga" initials="B." surname="Varga"/> <author fullname="J. Farkas" initials="J." surname="Farkas"/> <date month="March" year="2024"/> <abstract> <t indent="0">Deterministic Networking (DetNet), as defined in RFC 8655, aims to provide bounded end-to-end latency on top of the network infrastructure, comprising both Layer 2 bridged and Layer 3 routed segments. This document's primary purpose is to detail the specific requirements of the Operations, Administration, and Maintenance (OAM) recommended to maintain a deterministic network. The document will be used in future work that defines the applicability of and extension of OAM protocols for a deterministic network. With the implementation of the OAM framework in DetNet, an operator will have a real-time view of the network infrastructure regarding the network's ability to respect the Service Level Objective (SLO), such as packet delay, delay variation, and packet-loss ratio, assigned to each DetNet flow.</t> </abstract> </front> <seriesInfo name="RFC" value="9551"/> <seriesInfo name="DOI" value="10.17487/RFC9551"/> </reference> <reference anchor="RFC9913" target="https://www.rfc-editor.org/info/rfc9913" quoteTitle="true" derivedAnchor="RAW-TECHNOS"> <front> <title>Reliable and Available Wireless (RAW) Technologies</title> <author initials="P." surname="Thubert" fullname="Pascal Thubert" role="editor"> </author><date/><author initials="D." surname="Cavalcanti" fullname="Dave Cavalcanti"> <organization showOnFrontPage="true">Intel Corporation</organization> </author> <author initials="X." surname="Vilajosana" fullname="Xavier Vilajosana"> <organization showOnFrontPage="true">Universitat Oberta de Catalunya</organization> </author> <author initials="C." surname="Schmitt" fullname="Corinna Schmitt"> <organization showOnFrontPage="true">Research Institute CODE, UniBw M</organization> </author> <author initials="J." surname="Farkas" fullname="János Farkas"> <organization showOnFrontPage="true">Ericsson</organization> </author> <date month="April" year="2026"/> </front> <seriesInfo name="RFC" value="9913"/> <seriesInfo name="DOI" value="10.17487/RFC9913"/> </reference><xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9030.xml"/> <!-- 6TiSCH Architecture --> <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.4427.xml"/> <!--<reference anchor="RFC4427" target="https://www.rfc-editor.org/info/rfc4427" quoteTitle="true" derivedAnchor="RFC4427"> <front> <title>Recovery (Protection and Restoration) Terminology for Generalized Multi-Protocol Label Switching (GMPLS)</title> <author fullname="E. Mannie" initials="E." role="editor" surname="Mannie"/> <author fullname="D. Papadimitriou" initials="D." role="editor" surname="Papadimitriou"/> <date month="March" year="2006"/> <abstract> <t indent="0">This document defines a common terminology for Generalized Multi-Protocol Label Switching (GMPLS)-based recovery mechanisms (i.e., protection and restoration). The terminology is independent of the underlying transport technologies covered by GMPLS. This memo provides information for the InternetArchitecture --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6291.xml"/> <!-- Guidelinescommunity.</t> </abstract> </front> <seriesInfo name="RFC" value="4427"/> <seriesInfo name="DOI" value="10.17487/RFC4427"/> </reference> <reference anchor="RFC6291" target="https://www.rfc-editor.org/info/rfc6291" quoteTitle="true" derivedAnchor="RFC6291"> <front> <title>Guidelines for the Use of the "OAM" Acronym in the IETF</title> <author fullname="L. Andersson" initials="L." surname="Andersson"/> <author fullname="H. van Helvoort" initials="H." surname="van Helvoort"/> <author fullname="R. Bonica" initials="R." surname="Bonica"/> <author fullname="D. Romascanu" initials="D." surname="Romascanu"/> <author fullname="S. Mansfield" initials="S." surname="Mansfield"/> <date month="June" year="2011"/> <abstract> <t indent="0">At first glance, the acronym "OAM" seems to be well-known and well-understood. Looking at the acronym a bit more closely reveals a set of recurring problems that are revisited time and again.</t> <t indent="0">This document provides a definition of the acronym "OAM" (Operations, Administration, and Maintenance) for use in all future IETF--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7799.xml"/> <!--documents that refer to OAM. There are other definitions and acronyms that will be discussed while exploring the definition of the constituent parts of the "OAM" term. This memo documents an Internet Best Current Practice.</t> </abstract> </front> <seriesInfo name="BCP" value="161"/> <seriesInfo name="RFC" value="6291"/> <seriesInfo name="DOI" value="10.17487/RFC6291"/> </reference> <reference anchor="RFC7799" target="https://www.rfc-editor.org/info/rfc7799" quoteTitle="true" derivedAnchor="RFC7799"> <front> <title>Active and Passive Metrics and Methods (with Hybrid Types In-Between)</title> <author fullname="A. Morton" initials="A." surname="Morton"/> <date month="May" year="2016"/> <abstract> <t indent="0">This memo provides clear definitions for Active and Passive performance assessment. The construction of Metrics and Methods can be described as either "Active" or "Passive". Some methods may use a subset of both Active and Passive attributes, and we refer to these as "Hybrid Methods". This memo also describes multiple dimensions to help evaluate new methods as they emerge.</t> </abstract> </front> <seriesInfo name="RFC" value="7799"/> <seriesInfo name="DOI" value="10.17487/RFC7799"/> </reference> <reference anchor="RFC8557" target="https://www.rfc-editor.org/info/rfc8557" quoteTitle="true" derivedAnchor="RFC8557"> <front> <title>Deterministic Networking Problem Statement</title> <author fullname="N. Finn" initials="N." surname="Finn"/> <author fullname="P. Thubert" initials="P." surname="Thubert"/> <date month="May" year="2019"/> <abstract> <t indent="0">This paper documents the needs in various industries to establish multi-hop paths forOAM --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8557.xml"/> <!-- DetNet problem statement --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8655.xml"/> <!-- Deterministiccharacterized flows with deterministic properties.</t> </abstract> </front> <seriesInfo name="RFC" value="8557"/> <seriesInfo name="DOI" value="10.17487/RFC8557"/> </reference> <reference anchor="TSN" target="https://1.ieee802.org/tsn/" quoteTitle="true" derivedAnchor="TSN"> <front> <title>Time-Sensitive NetworkingArchitecture --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9551.xml"/>(TSN)</title> <author> <organization showOnFrontPage="true">IEEE</organization> </author> <date/> </front> </reference> </references><!--Normative References--> <references> <name>Informative<references pn="section-9.2"> <name slugifiedName="name-informative-references">Informative References</name><xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9049.xml"/> <!-- Path Aware Networking: Obstacles to Deployment --> <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.1122.xml"/> <!-- Internet<reference anchor="RFC9030" target="https://www.rfc-editor.org/info/rfc9030" quoteTitle="true" derivedAnchor="6TiSCH-ARCH"> <front> <title>An Architecture--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8939.xml"/> <!--for IPv6 over the Time-Slotted Channel Hopping Mode of IEEE 802.15.4 (6TiSCH)</title> <author fullname="P. Thubert" initials="P." role="editor" surname="Thubert"/> <date month="May" year="2021"/> <abstract> <t indent="0">This document describes a network architecture that provides low-latency, low-jitter, and high-reliability packet delivery. It combines a high-speed powered backbone and subnetworks using IEEE 802.15.4 time-slotted channel hopping (TSCH) to meet the requirements of low-power wireless deterministic applications.</t> </abstract> </front> <seriesInfo name="RFC" value="9030"/> <seriesInfo name="DOI" value="10.17487/RFC9030"/> </reference> <reference anchor="RFC8938" target="https://www.rfc-editor.org/info/rfc8938" quoteTitle="true" derivedAnchor="DetNet-DP"> <front> <title>Deterministic Networking (DetNet) Data Plane Framework</title> <author fullname="B. Varga" initials="B." role="editor" surname="Varga"/> <author fullname="J. Farkas" initials="J." surname="Farkas"/> <author fullname="L. Berger" initials="L." surname="Berger"/> <author fullname="A. Malis" initials="A." surname="Malis"/> <author fullname="S. Bryant" initials="S." surname="Bryant"/> <date month="November" year="2020"/> <abstract> <t indent="0">This document provides an overall framework for the Deterministic NetworkingIP dataplane --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8578.xml"/> <!--(DetNet) data plane. It covers concepts and considerations that are generally common to any DetNet data plane specification. It describes related Controller Plane considerations as well.</t> </abstract> </front> <seriesInfo name="RFC" value="8938"/> <seriesInfo name="DOI" value="10.17487/RFC8938"/> </reference> <reference anchor="RFC9938" target="https://www.rfc-editor.org/info/rfc9938" quoteTitle="true" derivedAnchor="DetNet-PLANE"> <front> <title>A Framework for the Deterministic Networking (DetNet) Controller Plane</title> <author fullname="A. Malis" initials="A." surname="Malis"/> <author fullname="X. Geng" initials="X." role="editor" surname="Geng"/> <author fullname="M. Chen" initials="M." surname="Chen"/> <author fullname="B. Varga" initials="B." surname="Varga"/> <author fullname="CJ. Bernardos" initials="CJ." surname="Bernardos"/> <date month="March" year="2026"/> <abstract> <t indent="0">This document provides a framework overview for the Deterministic Networking (DetNet) Controller Plane. It discusses concepts and requirements for the DetNet Controller Plane, which could be the basis for a future solution specification.</t> </abstract> </front> <seriesInfo name="RFC" value="9938"/> <seriesInfo name="DOI" value="10.17487/RFC9938"/> </reference> <reference anchor="RFC8175" target="https://www.rfc-editor.org/info/rfc8175" quoteTitle="true" derivedAnchor="DLEP"> <front> <title>Dynamic Link Exchange Protocol (DLEP)</title> <author fullname="S. Ratliff" initials="S." surname="Ratliff"/> <author fullname="S. Jury" initials="S." surname="Jury"/> <author fullname="D. Satterwhite" initials="D." surname="Satterwhite"/> <author fullname="R. Taylor" initials="R." surname="Taylor"/> <author fullname="B. Berry" initials="B." surname="Berry"/> <date month="June" year="2017"/> <abstract> <t indent="0">When routing devices rely on modems to effect communications over wireless links, they need timely and accurate knowledge of the characteristics of the link (speed, state, etc.) in order to make routing decisions. In mobile or other environments where these characteristics change frequently, manual configurations or the inference of state through routing or transport protocols does not allow the router to make the best decisions. This document introduces a new protocol called the Dynamic Link Exchange Protocol (DLEP), which provides a bidirectional, event-driven communication channel between the router and the modem to facilitate communication of changing link characteristics.</t> </abstract> </front> <seriesInfo name="RFC" value="8175"/> <seriesInfo name="DOI" value="10.17487/RFC8175"/> </reference> <reference anchor="RFC5714" target="https://www.rfc-editor.org/info/rfc5714" quoteTitle="true" derivedAnchor="FRR"> <front> <title>IP Fast Reroute Framework</title> <author fullname="M. Shand" initials="M." surname="Shand"/> <author fullname="S. Bryant" initials="S." surname="Bryant"/> <date month="January" year="2010"/> <abstract> <t indent="0">This document provides a framework for the development of IP fast- reroute mechanisms that provide protection against link or router failure by invoking locally determined repair paths. Unlike MPLS fast-reroute, the mechanisms are applicable to a network employing conventional IP routing and forwarding. This document is not an Internet Standards Track specification; it is published for informational purposes.</t> </abstract> </front> <seriesInfo name="RFC" value="5714"/> <seriesInfo name="DOI" value="10.17487/RFC5714"/> </reference> <reference anchor="RFC1122" target="https://www.rfc-editor.org/info/rfc1122" quoteTitle="true" derivedAnchor="INT-ARCH"> <front> <title>Requirements for Internet Hosts - Communication Layers</title> <author fullname="R. Braden" initials="R." role="editor" surname="Braden"/> <date month="October" year="1989"/> <abstract> <t indent="0">This RFC is an official specification for the Internet community. It incorporates by reference, amends, corrects, and supplements the primary protocol standards documents relating to hosts. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="STD" value="3"/> <seriesInfo name="RFC" value="1122"/> <seriesInfo name="DOI" value="10.17487/RFC1122"/> </reference> <reference anchor="NASA1" target="https://extapps.ksc.nasa.gov/Reliability/Documents/150814-3bWhatIsReliability.pdf" quoteTitle="true" derivedAnchor="NASA1"> <front> <title>RELIABILITY: Definition & Quantitative Illustration</title> <author initials="T." surname="Adams" fullname="Tim Adams"> <organization showOnFrontPage="true">NASA</organization> </author> <date/> </front> </reference> <reference anchor="NASA2" target="https://extapps.ksc.nasa.gov/Reliability/Documents/160727.1_Availability_What_is_it.pdf" quoteTitle="true" derivedAnchor="NASA2"> <front> <title>Availability</title> <author initials="T." surname="Adams" fullname="Tim Adams"> <organization showOnFrontPage="true">NASA</organization> </author> <date/> </front> </reference> <reference anchor="RFC9450" target="https://www.rfc-editor.org/info/rfc9450" quoteTitle="true" derivedAnchor="RAW-USE-CASES"> <front> <title>Reliable and Available Wireless (RAW) UseCases --> <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-raw-use-cases.xml"/> <!-- RAWCases</title> <author fullname="CJ. Bernardos" initials="CJ." role="editor" surname="Bernardos"/> <author fullname="G. Papadopoulos" initials="G." surname="Papadopoulos"/> <author fullname="P. Thubert" initials="P." surname="Thubert"/> <author fullname="F. Theoleyre" initials="F." surname="Theoleyre"/> <date month="August" year="2023"/> <abstract> <t indent="0">The wireless medium presents significant specific challenges to achieve properties similar to those of wired deterministic networks. At the same time, a number of use cases--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.0791.xml"/> <!-- IP --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.2205.xml"/> <!--cannot be solved with wires and justify the extra effort of going wireless. This document presents wireless use cases (such as aeronautical communications, amusement parks, industrial applications, pro audio and video, gaming, Unmanned Aerial Vehicle (UAV) and vehicle-to-vehicle (V2V) control, edge robotics, and emergency vehicles), demanding reliable and available behavior.</t> </abstract> </front> <seriesInfo name="RFC" value="9450"/> <seriesInfo name="DOI" value="10.17487/RFC9450"/> </reference> <reference anchor="RFC0791" target="https://www.rfc-editor.org/info/rfc791" quoteTitle="true" derivedAnchor="RFC0791"> <front> <title>Internet Protocol</title> <author fullname="J. Postel" initials="J." surname="Postel"/> <date month="September" year="1981"/> </front> <seriesInfo name="STD" value="5"/> <seriesInfo name="RFC" value="791"/> <seriesInfo name="DOI" value="10.17487/RFC0791"/> </reference> <reference anchor="RFC2205" target="https://www.rfc-editor.org/info/rfc2205" quoteTitle="true" derivedAnchor="RFC2205"> <front> <title>Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification</title> <author fullname="R. Braden" initials="R." role="editor" surname="Braden"/> <author fullname="L. Zhang" initials="L." surname="Zhang"/> <author fullname="S. Berson" initials="S." surname="Berson"/> <author fullname="S. Herzog" initials="S." surname="Herzog"/> <author fullname="S. Jamin" initials="S." surname="Jamin"/> <date month="September" year="1997"/> <abstract> <t indent="0">This memo describes version 1 of RSVP, a resource reservation setup protocol designed for an integrated services Internet. RSVP--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9522.xml"/> <!-- TE --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9544.xml"/> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.4655.xml"/> <!-- PCE --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.3366.xml"/> <!-- Adviceprovides receiver-initiated setup of resource reservations for multicast or unicast data flows, with good scaling and robustness properties. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="2205"/> <seriesInfo name="DOI" value="10.17487/RFC2205"/> </reference> <reference anchor="RFC3366" target="https://www.rfc-editor.org/info/rfc3366" quoteTitle="true" derivedAnchor="RFC3366"> <front> <title>Advice to link designers on link Automatic Repeat reQuest(ARQ) --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.4090.xml"/> <!-- Fast(ARQ)</title> <author fullname="G. Fairhurst" initials="G." surname="Fairhurst"/> <author fullname="L. Wood" initials="L." surname="Wood"/> <date month="August" year="2002"/> </front> <seriesInfo name="BCP" value="62"/> <seriesInfo name="RFC" value="3366"/> <seriesInfo name="DOI" value="10.17487/RFC3366"/> </reference> <reference anchor="RFC4090" target="https://www.rfc-editor.org/info/rfc4090" quoteTitle="true" derivedAnchor="RFC4090"> <front> <title>Fast Reroute Extensions to RSVP-TE--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.5880.xml"/> <!-- BFD --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.5714.xml"/> <!-- IP Fast Reroutefor LSP Tunnels</title> <author fullname="P. Pan" initials="P." role="editor" surname="Pan"/> <author fullname="G. Swallow" initials="G." role="editor" surname="Swallow"/> <author fullname="A. Atlas" initials="A." role="editor" surname="Atlas"/> <date month="May" year="2005"/> <abstract> <t indent="0">This document defines RSVP-TE extensions to establish backup label-switched path (LSP) tunnels for local repair of LSP tunnels. These mechanisms enable the re-direction of traffic onto backup LSP tunnels in 10s of milliseconds, in the event of a failure.</t> <t indent="0">Two methods are defined here. The one-to-one backup method creates detour LSPs for each protected LSP at each potential point of local repair. The facility backup method creates a bypass tunnel to protect a potential failure point; by taking advantage of MPLS label stacking, this bypass tunnel can protect a set of LSPs that have similar backup constraints. Both methods can be used to protect links and nodes during network failure. The described behavior and extensions to RSVP allow nodes to implement either method or both and to interoperate in a mixed network. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="4090"/> <seriesInfo name="DOI" value="10.17487/RFC4090"/> </reference> <reference anchor="RFC4655" target="https://www.rfc-editor.org/info/rfc4655" quoteTitle="true" derivedAnchor="RFC4655"> <front> <title>A Path Computation Element (PCE)-Based Architecture</title> <author fullname="A. Farrel" initials="A." surname="Farrel"/> <author fullname="J.-P. Vasseur" initials="J.-P." surname="Vasseur"/> <author fullname="J. Ash" initials="J." surname="Ash"/> <date month="August" year="2006"/> <abstract> <t indent="0">Constraint-based path computation is a fundamental building block for traffic engineering systems such as Multiprotocol Label Switching (MPLS) and Generalized Multiprotocol Label Switching (GMPLS) networks. Path computation in large, multi-domain, multi-region, or multi-layer networks is complex and may require special computational components and cooperation between the different network domains.</t> <t indent="0">This document specifies the architecture for a Path Computation Element (PCE)-based model to address this problem space. This document does not attempt to provide a detailed description of all the architectural components, but rather it describes a set of building blocks for the PCE architecture from which solutions may be constructed. This memo provides information for the Internet community.</t> </abstract> </front> <seriesInfo name="RFC" value="4655"/> <seriesInfo name="DOI" value="10.17487/RFC4655"/> </reference> <reference anchor="RFC5880" target="https://www.rfc-editor.org/info/rfc5880" quoteTitle="true" derivedAnchor="RFC5880"> <front> <title>Bidirectional Forwarding Detection (BFD)</title> <author fullname="D. Katz" initials="D." surname="Katz"/> <author fullname="D. Ward" initials="D." surname="Ward"/> <date month="June" year="2010"/> <abstract> <t indent="0">This document describes a protocol intended to detect faults in the bidirectional path between two forwarding engines, including interfaces, data link(s), and to the extent possible the forwarding engines themselves, with potentially very low latency. It operates independently of media, data protocols, and routing protocols. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="5880"/> <seriesInfo name="DOI" value="10.17487/RFC5880"/> </reference> <reference anchor="RFC6378" target="https://www.rfc-editor.org/info/rfc6378" quoteTitle="true" derivedAnchor="RFC6378"> <front> <title>MPLS Transport Profile (MPLS-TP) Linear Protection</title> <author fullname="Y. Weingarten" initials="Y." role="editor" surname="Weingarten"/> <author fullname="S. Bryant" initials="S." surname="Bryant"/> <author fullname="E. Osborne" initials="E." surname="Osborne"/> <author fullname="N. Sprecher" initials="N." surname="Sprecher"/> <author fullname="A. Fulignoli" initials="A." role="editor" surname="Fulignoli"/> <date month="October" year="2011"/> <abstract> <t indent="0">This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunications Union Telecommunications Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge (PWE3) architectures to support the capabilities and functionalities of a packet transport network as defined by the ITU-T.</t> <t indent="0">This document addresses the functionality described in the MPLS-TP Survivability Framework--> <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6378.xml"/> <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.6551.xml"/> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.7490.xml"/> <!-- Remote Loop-Free Alternate (LFA) Fast Reroute (FRR) --> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8724.xml"/> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8938.xml"/> <!--document (RFC 6372) and defines a protocol that may be used to fulfill the function of the Protection State Coordination for linear protection, as described in that document. [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="6378"/> <seriesInfo name="DOI" value="10.17487/RFC6378"/> </reference> <reference anchor="RFC6551" target="https://www.rfc-editor.org/info/rfc6551" quoteTitle="true" derivedAnchor="RFC6551"> <front> <title>Routing Metrics Used for Path Calculation in Low-Power and Lossy Networks</title> <author fullname="JP. Vasseur" initials="JP." role="editor" surname="Vasseur"/> <author fullname="M. Kim" initials="M." role="editor" surname="Kim"/> <author fullname="K. Pister" initials="K." surname="Pister"/> <author fullname="N. Dejean" initials="N." surname="Dejean"/> <author fullname="D. Barthel" initials="D." surname="Barthel"/> <date month="March" year="2012"/> <abstract> <t indent="0">Low-Power and Lossy Networks (LLNs) have unique characteristics compared with traditional wired and ad hoc networks that require the specification of new routing metrics and constraints. By contrast, with typical Interior Gateway Protocol (IGP) routing metrics using hop counts or link metrics, this document specifies a set of link and node routing metrics and constraints suitable to LLNs to be used by the Routing Protocol for Low-Power and Lossy Networks (RPL). [STANDARDS-TRACK]</t> </abstract> </front> <seriesInfo name="RFC" value="6551"/> <seriesInfo name="DOI" value="10.17487/RFC6551"/> </reference> <reference anchor="RFC8578" target="https://www.rfc-editor.org/info/rfc8578" quoteTitle="true" derivedAnchor="RFC8578"> <front> <title>Deterministic Networking Use Cases</title> <author fullname="E. Grossman" initials="E." role="editor" surname="Grossman"/> <date month="May" year="2019"/> <abstract> <t indent="0">This document presents use cases for diverse industries that have in common a need for "deterministic flows". "Deterministic" in this context means that such flows provide guaranteed bandwidth, bounded latency, and other properties germane to the transport of time-sensitive data. These use cases differ notably in their network topologies and specific desired behavior, providing as a group broad industry context for Deterministic Networking(DetNet) Data Plane(DetNet). For each use case, this document will identify the use case, identify representative solutions used today, and describe potential improvements that DetNet can enable.</t> </abstract> </front> <seriesInfo name="RFC" value="8578"/> <seriesInfo name="DOI" value="10.17487/RFC8578"/> </reference> <reference anchor="RFC8724" target="https://www.rfc-editor.org/info/rfc8724" quoteTitle="true" derivedAnchor="RFC8724"> <front> <title>SCHC: Generic Framework--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8175.xml"/> <!-- Dynamic Link Exchange Protocol --> <!--xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9016.xml"/--> <!-- Flowfor Static Context Header Compression andService Information ModelFragmentation</title> <author fullname="A. Minaburo" initials="A." surname="Minaburo"/> <author fullname="L. Toutain" initials="L." surname="Toutain"/> <author fullname="C. Gomez" initials="C." surname="Gomez"/> <author fullname="D. Barthel" initials="D." surname="Barthel"/> <author fullname="JC. Zuniga" initials="JC." surname="Zuniga"/> <date month="April" year="2020"/> <abstract> <t indent="0">This document defines the Static Context Header Compression and fragmentation (SCHC) framework, which provides both a header compression mechanism and an optional fragmentation mechanism. SCHC has been designed with Low-Power Wide Area Networks (LPWANs) in mind.</t> <t indent="0">SCHC compression is based on a common static context stored both in the LPWAN device and in the network infrastructure side. This document defines a generic header compression mechanism and its application to compress IPv6/UDP headers.</t> <t indent="0">This document also specifies an optional fragmentation and reassembly mechanism. It can be used to support the IPv6 MTU requirement over the LPWAN technologies. Fragmentation is needed for IPv6 datagrams that, after SCHC compression or when such compression was not possible, still exceed the Layer 2 maximum payload size.</t> <t indent="0">The SCHC header compression and fragmentation mechanisms are independent of the specific LPWAN technology over which they are used. This document defines generic functionalities and offers flexibility with regard to parameter settings and mechanism choices. This document standardizes the exchange over the LPWAN between two SCHC entities. Settings and choices specific to a technology or a product are expected to be grouped into profiles, which are specified in other documents. Data models for the context and profiles are out of scope.</t> </abstract> </front> <seriesInfo name="RFC" value="8724"/> <seriesInfo name="DOI" value="10.17487/RFC8724"/> </reference> <reference anchor="RFC8762" target="https://www.rfc-editor.org/info/rfc8762" quoteTitle="true" derivedAnchor="RFC8762"> <front> <title>Simple Two-Way Active Measurement Protocol</title> <author fullname="G. Mirsky" initials="G." surname="Mirsky"/> <author fullname="G. Jun" initials="G." surname="Jun"/> <author fullname="H. Nydell" initials="H." surname="Nydell"/> <author fullname="R. Foote" initials="R." surname="Foote"/> <date month="March" year="2020"/> <abstract> <t indent="0">This document describes the Simple Two-way Active Measurement Protocol (STAMP), which enables the measurement of both one-way and round-trip performance metrics, like delay, delay variation, and packet loss.</t> </abstract> </front> <seriesInfo name="RFC" value="8762"/> <seriesInfo name="DOI" value="10.17487/RFC8762"/> </reference> <reference anchor="RFC8939" target="https://www.rfc-editor.org/info/rfc8939" quoteTitle="true" derivedAnchor="RFC8939"> <front> <title>Deterministic Networking (DetNet) Data Plane: IP</title> <author fullname="B. Varga" initials="B." role="editor" surname="Varga"/> <author fullname="J. Farkas" initials="J." surname="Farkas"/> <author fullname="L. Berger" initials="L." surname="Berger"/> <author fullname="D. Fedyk" initials="D." surname="Fedyk"/> <author fullname="S. Bryant" initials="S." surname="Bryant"/> <date month="November" year="2020"/> <abstract> <t indent="0">This document specifies the Deterministic Networking (DetNet)--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9378.xml"/> <!-- Frameworkdata plane operation for IP hosts and routers that provide DetNet service to IP-encapsulated data. No DetNet-specific encapsulation is defined to support IP flows; instead, the existing IP-layer and higher-layer protocol header information is used to support flow identification and DetNet service delivery. This document builds on the DetNet architecture (RFC 8655) and data plane framework (RFC 8938).</t> </abstract> </front> <seriesInfo name="RFC" value="8939"/> <seriesInfo name="DOI" value="10.17487/RFC8939"/> </reference> <reference anchor="RFC9049" target="https://www.rfc-editor.org/info/rfc9049" quoteTitle="true" derivedAnchor="RFC9049"> <front> <title>Path Aware Networking: Obstacles to Deployment (A Bestiary of Roads Not Taken)</title> <author fullname="S. Dawkins" initials="S." role="editor" surname="Dawkins"/> <date month="June" year="2021"/> <abstract> <t indent="0">This document is a product of the Path Aware Networking Research Group (PANRG). At the first meeting of the PANRG, the Research Group agreed to catalog and analyze past efforts to develop and deploy Path Aware techniques, most of which were unsuccessful or at most partially successful, in order to extract insights and lessons for Path Aware networking researchers.</t> <t indent="0">This document contains that catalog and analysis.</t> </abstract> </front> <seriesInfo name="RFC" value="9049"/> <seriesInfo name="DOI" value="10.17487/RFC9049"/> </reference> <reference anchor="RFC9378" target="https://www.rfc-editor.org/info/rfc9378" quoteTitle="true" derivedAnchor="RFC9378"> <front> <title>In Situ Operations, Administration, and Maintenance(OAM)(IOAM) Deployment</title> <author fullname="F. Brockners" initials="F." role="editor" surname="Brockners"/> <author fullname="S. Bhandari" initials="S." role="editor" surname="Bhandari"/> <author fullname="D. Bernier" initials="D." surname="Bernier"/> <author fullname="T. Mizrahi" initials="T." role="editor" surname="Mizrahi"/> <date month="April" year="2023"/> <abstract> <t indent="0">In situ Operations, Administration, and Maintenance (IOAM) collects operational and telemetry information in the packet while the packet traverses a path between two points in the network. This document provides a framework for IOAM deployment and provides IOAM deployment considerations and guidance.</t> </abstract> </front> <seriesInfo name="RFC" value="9378"/> <seriesInfo name="DOI" value="10.17487/RFC9378"/> </reference> <reference anchor="RFC9473" target="https://www.rfc-editor.org/info/rfc9473" quoteTitle="true" derivedAnchor="RFC9473"> <front> <title>A Vocabulary of Path Properties</title> <author fullname="R. Enghardt" initials="R." surname="Enghardt"/> <author fullname="C. Krähenbühl" initials="C." surname="Krähenbühl"/> <date month="September" year="2023"/> <abstract> <t indent="0">Path properties express information about paths across a network and the services provided via such paths. In a path-aware network, path properties may be fully or partially available to entities such as endpoints. This document defines and categorizes path properties. Furthermore, the document identifies several path properties that might be useful to endpoints or other entities, e.g., for selecting between paths or for invoking some of the provided services. This document is a product of the Path Aware Networking Research Group (PANRG).</t> </abstract> </front> <seriesInfo name="RFC" value="9473"/> <seriesInfo name="DOI" value="10.17487/RFC9473"/> </reference> <reference anchor="RFC9544" target="https://www.rfc-editor.org/info/rfc9544" quoteTitle="true" derivedAnchor="RFC9544"> <front> <title>Precision Availability Metrics (PAMs) for Services Governed by Service Level Objectives (SLOs)</title> <author fullname="G. Mirsky" initials="G." surname="Mirsky"/> <author fullname="J. Halpern" initials="J." surname="Halpern"/> <author fullname="X. Min" initials="X." surname="Min"/> <author fullname="A. Clemm" initials="A." surname="Clemm"/> <author fullname="J. Strassner" initials="J." surname="Strassner"/> <author fullname="J. François" initials="J." surname="François"/> <date month="March" year="2024"/> <abstract> <t indent="0">This document defines a set of metrics for networking services with performance requirements expressed as Service Level Objectives (SLOs). These metrics, referred to as "Precision Availability Metrics (PAMs)", are useful for defining and monitoring SLOs. For example, PAMs can be used by providers and/or customers of an RFC 9543 Network Slice Service to assess whether the service is provided in compliance with its defined SLOs.</t> </abstract> </front> <seriesInfo name="RFC" value="9544"/> <seriesInfo name="DOI" value="10.17487/RFC9544"/> </reference> <reference anchor="RFC9633" target="https://www.rfc-editor.org/info/rfc9633" quoteTitle="true" derivedAnchor="RFC9633"> <front> <title>Deterministic Networking (DetNet) YANG Data Model</title> <author fullname="X. Geng" initials="X." surname="Geng"/> <author fullname="Y. Ryoo" initials="Y." surname="Ryoo"/> <author fullname="D. Fedyk" initials="D." surname="Fedyk"/> <author fullname="R. Rahman" initials="R." surname="Rahman"/> <author fullname="Z. Li" initials="Z." surname="Li"/> <date month="October" year="2024"/> <abstract> <t indent="0">This document contains the specification for the Deterministic Networking (DetNet)--> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.8762.xml"/> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9473.xml"/> <xi:include href="https://xml2rfc.tools.ietf.org/public/rfc/bibxml/reference.RFC.9633.xml"/> <!-- <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-opsawg-oam-characterization"/> --> <xi:include href="http://xml2rfc.tools.ietf.org/public/rfc/bibxml3/reference.I-D.ietf-detnet-controller-plane-framework"/>YANG data model for configuration and operational data for DetNet flows. The model allows the provisioning of an end-to-end DetNet service on devices along the path without depending on any signaling protocol. It also specifies operational status for flows.</t> <t indent="0">The YANG module defined in this document conforms to the Network Management Datastore Architecture (NMDA).</t> </abstract> </front> <seriesInfo name="RFC" value="9633"/> <seriesInfo name="DOI" value="10.17487/RFC9633"/> </reference> <referenceanchor="NASA1" target="https://extapps.ksc.nasa.gov/Reliability/Documents/150814-3bWhatIsReliability.pdf">anchor="RFC7490" target="https://www.rfc-editor.org/info/rfc7490" quoteTitle="true" derivedAnchor="RLFA-FRR"> <front><title>RELIABILITY: Definition & Quantitative Illustration</title><title>Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)</title> <authorinitials="T." surname="Adams" fullname="Tim Adams" > <organization>NASA</organization> </author> <date/>fullname="S. Bryant" initials="S." surname="Bryant"/> <author fullname="C. Filsfils" initials="C." surname="Filsfils"/> <author fullname="S. Previdi" initials="S." surname="Previdi"/> <author fullname="M. Shand" initials="M." surname="Shand"/> <author fullname="N. So" initials="N." surname="So"/> <date month="April" year="2015"/> <abstract> <t indent="0">This document describes an extension to the basic IP fast reroute mechanism, described in RFC 5286, that provides additional backup connectivity for point-to-point link failures when none can be provided by the basic mechanisms.</t> </abstract> </front> <seriesInfo name="RFC" value="7490"/> <seriesInfo name="DOI" value="10.17487/RFC7490"/> </reference> <referenceanchor="NASA2" target="https://extapps.ksc.nasa.gov/Reliability/Documents/160727.1_Availability_What_is_it.pdf">anchor="RFC9522" target="https://www.rfc-editor.org/info/rfc9522" quoteTitle="true" derivedAnchor="TE"> <front><title>Availability</title><title>Overview and Principles of Internet Traffic Engineering</title> <authorinitials="T." surname="Adams" fullname="Tim Adams" > <organization>NASA</organization> </author> <date/>fullname="A. Farrel" initials="A." role="editor" surname="Farrel"/> <date month="January" year="2024"/> <abstract> <t indent="0">This document describes the principles of traffic engineering (TE) in the Internet. The document is intended to promote better understanding of the issues surrounding traffic engineering in IP networks and the networks that support IP networking and to provide a common basis for the development of traffic-engineering capabilities for the Internet. The principles, architectures, and methodologies for performance evaluation and performance optimization of operational networks are also discussed.</t> <t indent="0">This work was first published as RFC 3272 in May 2002. This document obsoletes RFC 3272 by making a complete update to bring the text in line with best current practices for Internet traffic engineering and to include references to the latest relevant work in the IETF.</t> </abstract> </front> <seriesInfo name="RFC" value="9522"/> <seriesInfo name="DOI" value="10.17487/RFC9522"/> </reference><!--Informative References--></references> </references> <section numbered="false" removeInRFC="false" toc="include" pn="section-appendix.a"> <name slugifiedName="name-acknowledgments">Acknowledgments</name> <t indent="0" pn="section-appendix.a-1">This architecture could never have been completed without the support and recommendations from the DetNet chairs <contact fullname="Janos Farkas"/> and <contact fullname="Lou Berger"/>, and from <contact fullname="Dave Black"/>, the DetNet Tech Advisor. Many thanks to all of you. </t> <t indent="0" pn="section-appendix.a-2">The authors wish to thank <contact fullname="Ketan Talaulikar"/>, as well as <contact fullname="Balazs Varga"/>, <contact fullname="Dave Cavalcanti"/>, <contact fullname="Don Fedyk"/>, <contact fullname="Nicolas Montavont"/>, and <contact fullname="Fabrice Theoleyre"/> for their in-depth reviews during the development of this document. </t> <t indent="0" pn="section-appendix.a-3">The authors wish to thank <contact fullname="Acee Lindem"/>, <contact fullname="Eva Schooler"/>, <contact fullname="Rich Salz"/>, <contact fullname="Wesley Eddy"/>, <contact fullname="Behcet Sarikaya"/>, <contact fullname="Brian Haberman"/>, <contact fullname="Gorry Fairhurst"/>, <contact fullname="Éric Vyncke"/>, <contact fullname="Erik Kline"/>, <contact fullname="Roman Danyliw"/>, and <contact fullname="Dave Thaler"/> for their reviews and comments during the IETF Last Call and IESG review cycle. </t> <t indent="0" pn="section-appendix.a-4"> Special thanks for <contact fullname="Mohamed Boucadair"/>, <contact fullname="Giuseppe Fioccola"/>, and <contact fullname="Benoit Claise"/> for their help dealing with OAM technologies. </t> </section> <section numbered="false" toc="include" removeInRFC="false" pn="section-appendix.b"> <name slugifiedName="name-contributors">Contributors</name> <t indent="0" pn="section-appendix.b-1">The editor wishes to thank the following individuals for their contributions to the text and the ideas discussed in this document: </t> <contact fullname="Lou Berger"> <organization showOnFrontPage="true">LabN Consulting, L.L.C</organization> <address> <email>lberger@labn.net</email> </address> </contact> <contact fullname="Xavi Vilajosana"> <organization showOnFrontPage="true">Wireless Networks Research Lab, Universitat Oberta de Catalunya</organization> <address> <email>xvilajosana@gmail.com</email> </address> </contact> <contact fullname="Geogios Papadopolous"> <organization showOnFrontPage="true">IMT Atlantique</organization> <address> <email>georgios.papadopoulos@imt-atlantique.fr</email> </address> </contact> <contact fullname="Remous-Aris Koutsiamanis"> <organization showOnFrontPage="true">IMT Atlantique</organization> <address> <email>remous-aris.koutsiamanis@imt-atlantique.fr</email> </address> </contact> <contact fullname="Rex Buddenberg"> <organization showOnFrontPage="true">Retired</organization> <address> <email>buddenbergr@gmail.com</email> </address> </contact> <contact fullname="Greg Mirsky"> <organization showOnFrontPage="true">Ericsson</organization> <address> <email>gregimirsky@gmail.com</email> </address> </contact> </section> <section anchor="authors-addresses" numbered="false" removeInRFC="false" toc="include" pn="section-appendix.c"> <name slugifiedName="name-authors-address">Author's Address</name> <author initials="P" surname="Thubert" fullname="Pascal Thubert" role="editor"> <organization showOnFrontPage="true">Independent</organization> <address> <postal> <city>Roquefort-les-Pins</city> <code>06330</code> <country>France</country> </postal> <email>pascal.thubert@gmail.com</email> </address> </author> </section> </back> </rfc>