<?xmlversion="1.0" encoding="US-ASCII"?>version='1.0' encoding='UTF-8'?> <!DOCTYPE rfcSYSTEM "rfc2629.dtd"[ <!ENTITY nbsp " "> <!ENTITY zwsp "​"> <!ENTITY nbhy "‑"> <!ENTITY wj "⁠"> ]><?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?> <?rfc toc="yes"?> <?rfc symrefs="yes"?> <?rfc sortrefs="yes"?> <?rfc iprnotified="no"?> <?rfc strict="yes"?> <?rfc compact="yes"?> <?rfc subcompact="no"?><rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="info" docName="draft-ietf-detnet-mpls-over-ip-preof-11" number="9566" ipr="trust200902"submissionType="IETF">submissionType="IETF" obsoletes="" updates="" xml:lang="en" tocInclude="true" consensus="true" symRefs="true" sortRefs="true" version="3"> <front> <titleabbrev="abbrev="DetNet PREOFDetNet IP">via MPLS over UDP/IP"> Deterministic Networking(DetNet): DetNet PREOF(DetNet) Packet Replication, Elimination, and Ordering Functions (PREOF) via MPLS over UDP/IP</title> <seriesInfo name="RFC" value="9566"/> <author fullname="Balazs Varga" initials="B." surname="Varga"> <organization>Ericsson</organization> <address> <postal> <street>Magyar Tudosok krt. 11.</street> <city>Budapest</city> <country>Hungary</country> <code>1117</code> </postal> <email>balazs.a.varga@ericsson.com</email> </address> </author> <author fullname="Janos Farkas" initials="J." surname="Farkas"> <organization>Ericsson</organization> <address> <postal> <street>Magyar Tudosok krt. 11.</street> <city>Budapest</city> <country>Hungary</country> <code>1117</code> </postal> <email>janos.farkas@ericsson.com</email> </address> </author> <author fullname="Andrew G. Malis" initials="A." surname="Malis"> <organization>Malis Consulting</organization> <address> <email>agmalis@gmail.com</email> </address> </author><!-- <author fullname="James Bond" initials="J." surname="Bond"> <organization>MI6</organization> <address> <email>james@bond.com</email> </address> </author> --><date/>month="April" year="2024"/> <area>RTG</area> <workgroup>DetNet</workgroup> <keyword>DetNet</keyword> <keyword>IP Data Plane</keyword> <keyword>Service sub-layer</keyword> <keyword>Replication</keyword> <keyword>Elimination</keyword> <keyword>Ordering</keyword> <abstract> <t> This document describes how the DetNet IP data plane can support the Packet Replication, Elimination, and Ordering Functions (PREOF) built on the existing MPLS PREOF solution defined for the DetNet MPLSData Planedata plane and the mechanisms defined by MPLS-over-UDP technology. </t> </abstract> </front> <middle> <sectiontitle="Introduction" anchor="sec_intro">anchor="sec_intro" numbered="true" toc="default"> <name>Introduction</name> <t> The DetNet Working Group has defined Packet Replication (PRF), Packet Elimination(PEF)(PEF), and Packet Ordering (POF)functionsFunctions (represented as PREOF) to provide service protection by the DetNet service sub-layer <xreftarget="RFC8655"/>.target="RFC8655" format="default"/>. The PREOF service protection method relies on copies of the same packet sent over multiple maximally disjoint paths and uses sequencing information to eliminate duplicates. A possible implementation ofthePRF and PEFfunctionsis described in <xreftarget="IEEE8021CB"/>target="IEEE8021CB" format="default"/>, and the related YANG data model is defined in <xreftarget="IEEEP8021CBcv"/>.target="IEEE8021CBcv" format="default"/>. A possible implementation ofthePOFfunctionis described in <xreftarget="I-D.ietf-detnet-pof"/>.target="RFC9550" format="default"/>. <xreftarget="PREOF-scene"/>target="PREOF-scene" format="default"/> shows a DetNet flow on which PREOFfunctionsare applied during forwarding from the source to the destination. </t> <figuretitle="PREOF scenarioanchor="PREOF-scene"> <name>PREOF Scenario in a DetNetnetwork" anchor="PREOF-scene">Network</name> <artworkalign="center"><![CDATA[align="center" name="" type="" alt=""><![CDATA[ +------------+ +---------------E1---+ | | +---+ | | +---R3---+ | +---+ |src|------R1 +---+ | E3----O----+dst| +---+ | | E2-------+ +---+ +----------R2 | +-----------------+ R:replication functionReplication Function (PRF) E:elimination functionElimination Function (PEF) O:ordering functionOrdering Function (POF)]]> </artwork></figure>]]></artwork> </figure> <t> In general, the use of PREOFfunctionsrequire sequencing information to be included in the packets of a DetNet compound flow. This can be done by adding a sequence number ortime stamptimestamp as part of DetNet encapsulation. Sequencing information is typically added once, at or close to the source. </t> <t> The DetNet MPLS data plane <xreftarget="RFC8964"/>target="RFC8964" format="default"/> specifies how sequencing information is encoded in the MPLS header. However, the DetNet IP data plane described in <xreftarget="RFC8939"/>target="RFC8939" format="default"/> does not specify how sequencing information can be encoded in the IP packet. This document provides sequencing information to DetNet IP nodes, so it results in an improved version of the DetNet IP data plane. As suggested by <xreftarget="RFC8938"/>,target="RFC8938" format="default"/>, the solution uses existing standardized headers and encapsulations. The improvement is achieved byre-usingreusing the DetNetMPLS over UDP/IPMPLS-over-UDP/IP data plane <xreftarget="RFC9025"/>target="RFC9025" format="default"/> with the restriction of using zeroF-labels.F-Labels. </t> </section><!-- end of introduction --><sectiontitle="Terminology">numbered="true" toc="default"> <name>Terminology</name> <sectiontitle="Termsnumbered="true" toc="default"> <name>Terms Used in ThisDocument">Document</name> <t> This document uses the terminology established in the DetNet architecture <xreftarget="RFC8655"/>,target="RFC8655" format="default"/>, and it is assumed that the reader isassumed to befamiliar with that document and its terminology. </t> </section> <sectiontitle="Abbreviations">numbered="true" toc="default"> <name>Abbreviations</name> <t> The following abbreviations are used in this document:<list style="hanging" hangIndent="14"> <t hangText="DetNet">Deterministic Networking.</t> <t hangText="PEF">Packet</t> <dl newline="false" spacing="normal" indent="14"> <dt>DetNet</dt> <dd>Deterministic Networking</dd> <dt>PEF</dt> <dd>Packet EliminationFunction.</t> <t hangText="POF">PacketFunction</dd> <dt>POF</dt> <dd>Packet OrderingFunction.</t> <t hangText="PREOF">PacketFunction</dd> <dt>PREOF</dt> <dd>Packet Replication,EliminationElimination, and OrderingFunctions.</t> <t hangText="PRF">PacketFunctions</dd> <dt>PRF</dt> <dd>Packet ReplicationFunction.</t> </list> </t>Function</dd> </dl> </section><!-- <section title="Requirements Language"> <t> The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they appear in all capitals, as shown here. </t></section>--> </section> <!-- end of terminology --> <!-- ===================================================================== --><section anchor="req-on-pof"title="Requirementsnumbered="true" toc="default"> <name>Requirements foraddingAdding PREOF to DetNetIP">IP</name> <t> The requirements for adding PREOF to DetNet IP are:<list style="symbols"></t> <ul spacing="normal"> <li> <t>to reuse existing DetNet data plane solutions (e.g., <xreftarget="RFC8964"/>,target="RFC8964" format="default"/>, <xreftarget="RFC9025"/>). </t>target="RFC9025" format="default"/>), and</t> </li> <li> <t>to allow the DetNet service sub-layer for IPpacket switchedpacket-switched networks with minimal implementation effort. </t></list> </t></li> </ul> <t> The described solutionpractically gains fromleverages MPLS header fields without requiring the support of the MPLS forwarding plane. </t> </section><!-- end of requirements --><section anchor="pof-alg"title="Addingnumbered="true" toc="default"> <name>Adding PREOF to DetNetIP">IP</name> <section anchor="preof-relations"title="Solution Basics">numbered="true" toc="default"> <name>Solution Basics</name> <t> The DetNet IP encapsulation supporting the DetNetServiceservice sub-layer is based on the "UDP tunneling" concept. The solution creates a set of underlay UDP/IP tunnels between an overlay set of DetNet relay nodes. </t> <t> At the edge of aPREOF capablePREOF-capable DetNet IPdomaindomain, the DetNet flow is encapsulated inana UDP packet containing the sequence number used by PREOFfunctionswithin the domain. This solution maintains the 6-tuple-based DetNet flow identification in DetNet transit nodes, which operate at the DetNet forwarding sub-layer between the DetNet service sub-layer nodes; therefore, it is compatible with <xreftarget="RFC8939"/>.target="RFC8939" format="default"/>. <xreftarget="PREOF-IP-basics"/>target="PREOF-IP-basics" format="default"/> shows how thePREOF capablePREOF-capable DetNet IP data plane fits into the DetNet sub-layers. </t> <figuretitle="PREOF capableanchor="PREOF-IP-basics"> <name>PREOF-Capable DetNet IPdata plane" anchor="PREOF-IP-basics">Data Plane</name> <artworkalign="center"><![CDATA[align="center" name="" type="" alt=""><![CDATA[ DetNet IP . . +------------+ | Service | d-CW, Service-ID(S-label)(S-Label) +------------+ | Forwarding | UDP/IP Header +------------+ *d-CW: DetNet Control Word]]> </artwork></figure>]]></artwork> </figure> </section><!-- end of Solution basics --><section anchor="pof-blocks"title="Encapsulation">numbered="true" toc="default"> <name>Encapsulation</name> <t> ThePREOF capablePREOF-capable DetNet IP encapsulation builds on encapsulating DetNetPseudoWirepseudowire (PW) directly over UDP. That is, it combines DetNet MPLS <xreftarget="RFC8964"/>target="RFC8964" format="default"/> with DetNet MPLS-in-UDP <xreftarget="RFC9025"/>,target="RFC9025" format="default"/>, without using anyF-LabelsF-Labels, as shown in <xreftarget="PREOF-IP-encap"/>.target="PREOF-IP-encap" format="default"/>. DetNet flows are identified at the receiving DetNet service sub-layer processing node via the S-Label and/or the UDP/IP header information. Sequencing information for PREOF is provided by the DetNet Control Word (d-CW)asper <xreftarget="RFC8964"/>.target="RFC8964" format="default"/>. TheS-labelS-Label is used to identify both the DetNet flow and the DetNet App-flow type. The UDP tunnel is used to direct the packet across the DetNet domain to the next DetNet service sub-layer processing node. </t> <figuretitle="PREOF capableanchor="PREOF-IP-encap"> <name>PREOF-Capable DetNet IPencapsulation" anchor="PREOF-IP-encap">Encapsulation</name> <artworkalign="center"><![CDATA[align="center" name="" type="" alt=""><![CDATA[ +---------------------------------+ | | | DetNet App-Flow | |(original(Original IP) Packet | | | +---------------------------------+ <--\ | DetNet Control Word | | +---------------------------------+ +-->PREOF capablePREOF-capable | Service-ID (S-Label) | | DetNet IP data +---------------------------------+ | plane encapsulation | UDP Header | | +---------------------------------+ | | IP Header | | +---------------------------------+ <--/ | Data-Link | +---------------------------------+ | Physical | +---------------------------------+]]> </artwork></figure>]]></artwork> </figure> </section><!-- end of Encapsulation --><section anchor="PREOF-IP-proc"title="Packet Processing">numbered="true" toc="default"> <name>Packet Processing</name> <t> IP ingress and egress nodes of thePREOF capablePREOF-capable DetNet IP domain add and remove a DetNet service-specific d-CW and Service-ID (i.e., S-Label). Relay nodes can change Service-ID values when processing a DetNet flow, i.e., incoming and outgoing Service-IDs of a DetNet flow can be different. Service-ID values are provisioned per DetNet service via configuration, e.g., via the Controller Plane described in <xreftarget="RFC8938"/>.target="RFC8938" format="default"/>. In some PREOF topologies, the node performing replication sends the packets to multiple nodesperformingperforming, e.g., PEF orPOFPOF, and the replication node can use different Service-ID values for the different member flows for the same DetNet service. </t> <t>Note,Note thatService-IDsthe Service-ID is a local ID on the receiver sideproviding identification ofthat identifies the DetNet flow at the downstream DetNet service sub-layer receiver. </t> </section><!-- end of Packet processing --><section anchor="aggr"title="Flow Aggregation">numbered="true" toc="default"> <name>Flow Aggregation</name> <t> Two methods can be used for flow aggregation:<list style="symbols"></t> <ul spacing="normal"> <li> <t>aggregation using same UDP tunnel, and </t><t>aggregating</li> <li> <t>aggregation of DetNet flows as a new DetNet flow. </t></list> </t></li> </ul> <t> In the firstcase,method, the different DetNetPseudoWirespseudowires use the same UDP tunnel, so they are treated as a single (aggregated) flow at the forwarding sub-layer. At the service sub-layer, each flow uses a differentService IDService-ID (see <xreftarget="PREOF-IP-encap"/> ).target="PREOF-IP-encap" format="default"/>). </t> <t> For the secondoption,method, an additional hierarchy is createdthanks toby adding an additional Service-ID and d-CW tupleaddedto the encapsulation. The Aggregate-ID is a special case of a Service-ID, whose properties are known only at the aggregation andde-aggregationdeaggregation end points. It is a property of the Aggregate-ID that it is followed by a d-CW followed by a Service-ID/d-CW tuple. <xreftarget="PREOF-IP-aggr"/>target="PREOF-IP-aggr" format="default"/> shows the encapsulation in the case of aggregation. </t> <figuretitle="Aggregatinganchor="PREOF-IP-aggr"> <name>Aggregating DetNetflowsFlows as anewNew DetNetflow" anchor="PREOF-IP-aggr">Flow</name> <artworkalign="center"><![CDATA[align="center" name="" type="" alt=""><![CDATA[ +---------------------------------+ | | | DetNet App-Flow | | Payload Packet | | | +---------------------------------+ <--\ | DetNet Control Word | | +---------------------------------+ +-->PREOF capablePREOF-capable | Service-ID (S-Label) | | DetNet IP data +---------------------------------+ | plane encapsulation | DetNet Control Word | | +---------------------------------+ | | Aggregate-ID (A-Label) | | +---------------------------------+ | | UDP Header | | +---------------------------------+ | | IP Header | | +---------------------------------+ <--/ | Data-Link | +---------------------------------+ | Physical | +---------------------------------+]]> </artwork></figure>]]></artwork> </figure> <t> Theoption used foraggregation method isknown by configuration ofconfigured in theaggregation/de-aggregationaggregation/deaggregation nodes. </t> <t> If severalDetnetDetNet flows are aggregated in a single UDP tunnel, they all need to follow the same path in the network. </t> </section><!-- end of Flow Aggregation --><section anchor="PREOF-proc"title="PREOF Processing">numbered="true" toc="default"> <name>PREOF Processing</name> <t> A node operating on a received DetNet flow at the DetNet service sub-layer uses the local context associated with a received Service-ID to determine which local DetNet operation(s) are applied to the received packet. A unique Service-ID can be allocatedto be uniqueandenablingcan be used to identify a DetNet flowidentificationregardless of which input interface or UDP tunnel receives thepacket is received.packet. It is important to note that Service-ID values are driven by the receiver, not the sender. </t> <t> The DetNet forwarding sub-layer is supported by the UDP tunnel and is responsible for providing resource allocation and explicit routes. </t> <t> The outgoing PREOF encapsulation and processing can be implemented via the provisioning of UDP and IP header information. Note, when PRF is performed at the DetNet service sub-layer, there are multiple member flows, and each member flow requirestheirits own Service-ID, UDP header information, and IP header information. The headers for each outgoing packet are formatted according to the configuration information, and the UDP Source Port value is set to uniquely identify the DetNet flow. The packet is then handled as aPREOF capablePREOF-capable DetNet IP packet. </t> <t> The incoming PREOF processing can be implementedviaby assigning a Service-ID to theprovisioning ofreceivedService-ID,DetNet flow and processing the information in the UDP and IPheader information.headers. The provisioned information is used to identify incomingapp-flowsApp-flows based on the combination of Service-ID and/or incoming encapsulation header information. </t> </section><!-- end of PREOF procedures --><section anchor="PREOF-IP-domain"title="PREOF capablenumbered="true" toc="default"> <name>PREOF-Capable DetNet IPdomain">Domain</name> <t> <xreftarget="PREOF-domain"/>target="PREOF-domain" format="default"/> shows using PREOF in aPREOF capablePREOF-capable DetNet IP network, where service protection is provided end to end,anand not only withinsub-networks likesub-networks, as is depicted inFigure 4<eref target="https://www.rfc-editor.org/rfc/rfc8939#figure-4" brackets="angle">Figure 4</eref> of <xreftarget="RFC8939"/>.target="RFC8939" format="default"/>. </t> <figuretitle="PREOF capableanchor="PREOF-domain"> <name>PREOF-Capable DetNet IPdomain" anchor="PREOF-domain">Domain</name> <artworkalign="center"><![CDATA[align="center" name="" type="" alt=""><![CDATA[ <----------PREOF capablePREOF-capable DetNet IP ---------------> ______ ____ / \__ ____ / \__/ \____________ +----+ __/ \____/ \ +----+ |src |_____/ \___| dst| +----+ \_______ DetNet network __________/ +----+ \_______ _/ \ __ __/ \_______/ \___/ +------------+ +---------------E1---+ | | +----+ | | +---R3---+ | +----+ |src |------R1 +---+ | E3----O----+ dst| +----+ | | E2-------+ +----+ +----------R2 | +-----------------+]]> </artwork></figure>]]></artwork> </figure> </section><!-- end of PREOF capable DetNet IP domain --></section><!-- end of Adding PREOF to DetNet IP --><section anchor="ctrl-mngmnt-PREOF-IP"title="Controlnumbered="true" toc="default"> <name>Control and Management PlaneParameters">Parameters</name> <t> The information needed to identify individual and aggregated DetNet flows is summarized as follows:<list style="symbols"></t> <ul spacing="normal"> <li> <t>Service-ID information to be mapped to UDP/IP flows. Note that, for example, a single Service-ID can map to multiple sets of UDP/IP information when PREOF is used.</t> </li> <li> <t>IPv4 or IPv6source addressSource Address field.</t> </li> <li> <t>IPv4 or IPv6 source address prefix length, where a zero (0) value effectively means that the address field is ignored.</t> </li> <li> <t>IPv4 or IPv6destination addressDestination Address field.</t> </li> <li> <t>IPv4 or IPv6 destination address prefix length, where a zero (0) effectively means that the address field is ignored.</t> </li> <li> <t>IPv6flow labelFlow Label field.</t> </li> <li> <t>IPv4protocolProtocol field being equal to "UDP". </t> </li> <li> <t>IPv6 (last)next headerNext Header field being equal to "UDP".</t> </li> <li> <t>For the IPv4 Type of Service and IPv6 Traffic ClassFields: <list style="symbols">fields: </t> <ul spacing="normal"> <li> <t>Whether or not theDSCPDifferentiated Services Code Point (DSCP) field is used in flowidentificationidentification, as the use of the DSCP field for flow identification is optional.</t> </li> <li> <t>If the DSCP field is used to identify a flow, then the flow identification information (for that flow) includes a list of DSCPs used by the given DetNet flow.</t></list></t></li> </ul> </li> <li> <t>UDP Source Port. Support for both exact and wildcard matching is required. Port ranges can optionally be used.</t> </li> <li> <t>UDP Destination Port. Support for both exact and wildcard matching is required. Port ranges can optionally be used.</t> </li> <li> <t>For end systems, an optional maximum IP packet size that should be used for that outgoing DetNet IP flow.</t></list></li> </ul> <t> This information is provisioned per DetNet flow via configuration, e.g., via thecontroller plane.Controller Plane. </t> <t> Ordering of the set of information used to identify an individual DetNet flow can, for example, be used to provide a DetNet service for a specific UDP flow, with unique Source and Destination Port field values, while providing a different service for the aggregate of all other flows with that same UDP Destination Port value. </t> <t> The minimum set of information for the configuration of the DetNet service sub-layer is summarized as follows:<list style="symbols"></t> <ul spacing="normal"> <li> <t>App-flow identificationinformation.information </t> </li> <li> <t>Sequence numberlength.</t> <t>PREOF + related Service-ID(s).</t>length</t> </li> <li> <t>Type of PREOF to be executed on the DetNet flow</t> </li> <li> <t>Service-ID(s) used by the member flows</t> </li> <li> <t>Associated forwarding sub-layerinformation.</t>information</t> </li> <li> <t>Service aggregationinformation.</t> </list> </t>information</t> </li> </ul> <t> The minimum set of information for the configuration of the DetNet forwarding sub-layer is summarized as follows:<list style="symbols"></t> <ul spacing="normal"> <li> <t>UDPtunnel specific information.tunnel-specific information </t> </li> <li> <t>Trafficparameters.</t> </list> </t>parameters</t> </li> </ul> <t> These parameters are defined in the DetNetFlowflow andServiceservice information model <xreftarget="RFC9016"/>target="RFC9016" format="default"/> and the DetNet YANG model. </t> <t> Note: this document focuses on the use ofMPLS over UDP/IPMPLS-over-UDP/IP encapsulation throughout an entire DetNet IP network, making MPLS-based DetNetOAMOperations, Administration, and Maintenance (OAM) techniques applicable <xreftarget="I-D.ietf-detnet-mpls-oam"/>.target="RFC9546" format="default"/>. Using the described encapsulation only for a portion of a DetNet IP network that handlesthePREOFfunctionalitywould complicate OAM. </t> </section><!-- end of PREOF-IP management --> <!-- ===================================================================== --><sectiontitle="Security Considerations">numbered="true" toc="default"> <name>Security Considerations</name> <t> There are no newDetNet relatedDetNet-related security considerations introduced by this solution. Security considerations of DetNet MPLS <xreftarget="RFC8964"/>target="RFC8964" format="default"/> and DetNet MPLS over UDP/IP <xreftarget="RFC9025"/>target="RFC9025" format="default"/> apply. </t> </section> <section anchor="iana"title="IANA Considerations">numbered="true" toc="default"> <name>IANA Considerations</name> <t> This documentmakeshas no IANArequests. </t> </section> <section anchor="acks" title="Acknowledgements"> <t> Authors extend their appreciation to Stewart Bryant, Pascal Thubert, David Black, Shirley Yangfan and Greg Mirsky for their insightful comments and productive discussion that helped to improve the document.actions. </t> </section> </middle> <back><references title="Normative References"> <!-- <?rfc include="reference.RFC.2119"?> <?rfc include="reference.RFC.8174"?> --> <?rfc include="reference.RFC.8655"?> <?rfc include="reference.RFC.8938"?> <?rfc include="reference.RFC.8939"?> <?rfc include="reference.RFC.8964"?> <?rfc include="reference.RFC.9016"?> <?rfc include="reference.RFC.9025"?> <?rfc include="reference.I-D.ietf-detnet-mpls-oam"?><references> <name>References</name> <references> <name>Normative References</name> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8655.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8938.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8939.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8964.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9016.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9025.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9546.xml"/> </references><references title="Informative References"> <?rfc include="reference.I-D.ietf-detnet-pof"?><references> <name>Informative References</name> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9550.xml"/> <referenceanchor="IEEE8021CB" target="https://standards.ieee.org/standard/802_1CB-2017.html">anchor="IEEE8021CB"> <front> <title>IEEE Standard for Local and metropolitan area networks -- Frame Replication and Elimination for Reliability </title> <author> <organization>IEEE</organization> </author> <date month="October" year="2017"/> </front> <seriesInfo name="IEEE Std" value="802.1CB-2017"/> <seriesInfo name="DOI"value="10.1109/IEEESTD.2017.8091139" />value="10.1109/IEEESTD.2017.8091139"/> </reference> <referenceanchor="IEEEP8021CBcv" target="https://www.ieee802.org/1/files/private/cv-drafts/d1/802-1CBcv-d1-2.pdf">anchor="IEEE8021CBcv"> <front><title>FRER<title>IEEE Standard for Local and metropolitan area networks -- Frame Replication and Elimination for Reliability - Amendment 1: Information Model, YANG DataModelModel, and Management Information Base Module</title><author initials="S." surname="Kehrer" fullname="Stephan Kehrer"> <organization>IEEE 802.1</organization><author> <organization>IEEE</organization> </author> <datemonth="March" year="2021"/>month="February" year="2022"/> </front> <refcontent>Amendment to IEEE Std 802.1CB-2017</refcontent> <seriesInfo name="IEEEP802.1CBcv /D1.2" value="P802.1CBcv"/> <format type="PDF" target="https://www.ieee802.org/1/files/private/cv-drafts/d1/802-1CBcv-d1-2.pdf"/>Std" value="802.1CBcv-2021"/> <seriesInfo name="DOI" value="10.1109/IEEESTD.2022.9715061"/> </reference> </references> </references> <section anchor="acks" numbered="false" toc="default"> <name>Acknowledgements</name> <t> Authors extend their appreciation to <contact fullname="Stewart Bryant"/>, <contact fullname="Pascal Thubert"/>, <contact fullname="David Black"/>, <contact fullname="Shirley Yangfan"/>, and <contact fullname="Greg Mirsky"/> for their insightful comments and productive discussion that helped to improve the document. </t> </section> </back> </rfc>