Operations, Administration and Maintenance (OAM) Requirements for Bit Index Explicit Replication (BIER) Layer
draft-ietf-bier-oam-requirements-21

BIER Working Group                                        G. Mirsky, Ed.
Internet-Draft                                                  Ericsson
Intended status: Informational                                  N. Kumar
Expires: 27 May 2026                                              Oracle
                                                                 M. Chen
                                                     Huawei Technologies
                                                      S. Pallagatti, Ed.
                                                                  VMware
                                                        23 November 2025

 Operations, Administration and Maintenance (OAM) Requirements for Bit
                Index Explicit Replication (BIER) Layer
                  draft-ietf-bier-oam-requirements-21

Abstract

   This document specifies a list of functional requirements for
   Operations, Administration, and Maintenance mechanisms, protocols,
   and tools that support operations in the Bit Index Explicit
   Replication layer of a network.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   This Internet-Draft will expire on 27 May 2026.

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   Copyright (c) 2025 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   Please review these documents carefully, as they describe your rights

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   and restrictions with respect to this document.  Code Components
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   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Conventions used in this document . . . . . . . . . . . .   2
       1.1.1.  Terminology . . . . . . . . . . . . . . . . . . . . .   2
       1.1.2.  Requirements Language . . . . . . . . . . . . . . . .   3
       1.1.3.  Acronyms  . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   6.  Normative References  . . . . . . . . . . . . . . . . . . . .   7
   7.  Informative References  . . . . . . . . . . . . . . . . . . .   7
   Contributors' Addresses . . . . . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   [RFC8279] specifies a Bit Index Explicit Replication (BIER)
   architecture and how it supports forwarding of multicast data
   packets.

   This document lists the Operations, Administration, and Maintenance
   (OAM) requirements for the BIER layer (Section 4.2 of [RFC8279]) of
   the multicast domain.  The list can further be used for gap analysis
   of available OAM tools to identify possible enhancements of existing
   or whether new OAM tools are required to support proactive and on-
   demand path monitoring and service validation.

1.1.  Conventions used in this document

1.1.1.  Terminology

   The reader is expected to be familiar with:

   *  [RFC7799], particularly definitions of Active, Passive, and Hybrid
      measurement methods and metrics.

   *  The definitions and calculation of performance metrics, e.g.,
      throughput, loss, delay, and delay variation metrics, are defined
      in [RFC6374].

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   *  The definitions, applicability, and examples of the Continuity
      Check and Connectivity Verification mechanisms, components of the
      Fault Management OAM, can be found in [RFC5860],[RFC6371], and
      [RFC7276].

   *  A multicast domain is a network segment that defines the scope for
      the multicast traffic, allowing it to be exchanged only among
      systems within the domain [RFC8279].

   *  The term "BIER OAM" is used in this document interchangeably with
      "a set of OAM protocols, methods, and tools for the BIER layer".

   *  Downstream - is the direction from the ingress toward the egress
      endpoints of a multicast distribution tree.

   *  Egress endpoint is a router to which the packet needs to be sent
      [RFC8279].

   *  Ingress endpoint is a router that encapsulates a packet in a BIER
      header [RFC8279].

   *  A BIER OAM session is a communication established between Bit-
      Forwarding Routers (BFR) to perform OAM functions like fault
      detection, performance monitoring, and localization [RFC7276].
      These sessions can be proactive (continuous, persistent
      configuration) or on-demand (manual, temporary diagnostics).

1.1.2.  Requirements Language

   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 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

   The requirements language is used in Section 2 and applies to
   implementations of BIER OAM conformant to the listed requirements.

1.1.3.  Acronyms

   BFD: Bidirectional Forwarding Detection [RFC8562]

   BFR: Bit-Forwarding Router [RFC8279]

   BFER: Bit-Forwarding Egress Router [RFC8279]

   BIER: Bit Index Explicit Replication [RFC8279]

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   OAM: Operations, Administration, and Maintenance [RFC6291]

   PMTUD: Path Maximum Transmission Unit Discovery [RFC1191]

   p2mp: Point-to-Multipoint [RFC8562]

   RDI: Remote Defect Indication [RFC6428]

   STAMP: Simple Two-way Active Measurement Protocol [RFC8762]

2.  Requirements

   This section lists the requirements for OAM of the BIER layer:

   1.  The listed requirements MUST be supported with any routing
       underlay [RFC8279] over which the BIER layer can be realized.

   2.  It MUST be possible to initialize a BIER OAM session from any BFR
       of the given BIER domain.

   3.  It MUST be possible to initialize a BIER OAM session from a
       controller.

   4.  BIER OAM MUST support proactive OAM monitoring and measurement
       methods.

   5.  BIER OAM MUST support on-demand OAM monitoring and measurement
       methods.

   6.  BIER OAM MUST support active performance measurement methods
       [RFC7799].

   7.  BIER OAM MUST support passive performance measurement methods
       [RFC7799].

   8.  BIER OAM MUST support the ability of any BFR in the given BIER
       domain to monitor Bit-Forwarding Egress Router (BFER)
       availability proactively.

   This requirement provides helpful clarification to the combination of
   Requirements 2 and 4.  The p2mp BFD with active tail support
   [RFC9780] is an example of a protocol that provides notifications
   about the loss of connectivity in a multicast distribution tree.

   9.  BIER OAM MUST support downstream path continuity check.

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   Bidirectional Forwarding Detection (BFD) [RFC8562] is an example of a
   protocol that monitors the continuity of a multicast distribution
   tree.

   10. BIER OAM MUST support downstream performance measurement.

   Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] is an
   example of a protocol that supports measurement of performance
   metrics, e.g., packet loss ratio, delay, and delay variation.

   11. In the downstream direction, a BIER OAM solution MUST support
       transmission of OAM packets to traverse the same set of nodes and
       links and receive the same forwarding treatment (including QoS)
       as the monitored BIER flow.

   In some cases, e.g., when monitoring a composite data flow that
   includes several sub-flows characterized by different CoS marking, an
   operator may choose to monitor the continuity of the path at the
   highest CoS, not at every CoS value in the data flow.  In that case,
   BIER OAM packets traverse the same set of nodes and links as the
   composite data flow while receiving the same forwarding treatment as
   the highest CoS sub-flow.  In this scenario, the state of path
   continuity for lower CoS sub-flows can be derived from the state of
   the highest CoS, as determined by the BIER OAM protocol performing
   continuity verification (e.g., BFD).

   12. BIER OAM MUST support bidirectional OAM methods.  In the
       downstream direction, these methods of monitoring or measurement
       MUST conform to Requirement 11.  In the reverse direction (i.e.,
       from the egress toward the ingress endpoint of the BIER OAM test
       session), BIER OAM packets MAY deviate from traversing the same
       set of nodes and links, or receive a different forwarding
       treatment (including QoS) as the monitored BIER flow.

   Point-to-Multipoint (p2mp) BFD with active tail [RFC9780]) is an
   example of the bidirectional mechanism of continuity checking.

   13. BIER OAM MUST support Path Maximum Transmission Unit discovery
       (PMTUD).

   The PMTUD using ICMP [RFC1191] is an example of the mechanism.

   14. BIER OAM MUST support an RDI mechanism to notify the BFR, the
       source of the continuity checking by BFERs.

   The Diagnostic field in p2mp BFD with active tail support, as
   described in Section 5 of [RFC9780], is an example of the RDI
   mechanism.

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   15. BIER OAM MUST support downstream performance measurement
       method(s) that (together) calculate performance metrics, e.g.,
       throughput, loss, delay, and delay variation metrics [RFC6374].

   STAMP ([RFC8762] and [RFC8972]) is an example of an active
   performance measurement method of performance metrics that may be
   applied in a BIER domain.  The Alternate Marking Method, described in
   [RFC9341] and [RFC9342], is an example of a hybrid measurement method
   ([RFC7799]) that may be applied in a BIER domain.

   16. BIER OAM MUST support defect notification mechanism(s).

   Alarm Indication Signal [RFC6427] is an example of the defect
   notification mechanism.

   17. BIER OAM MUST support a way for any BFR in the given BIER domain
       to originate a fault management message addressed to any subset
       of BFRs within the domain.

   [RFC6427] provides an example of a Fault Management messaging
   mechanism.

   18. BIER OAM MUST support methods to enable the survivability of a
       BIER layer.

   Protection switching and restoration are examples of survivability
   methods.

3.  IANA Considerations

   This document does not propose any IANA consideration.  This section
   may be removed.

4.  Security Considerations

   This document lists the OAM requirements for a BIER-enabled domain
   and thus inherits the security considerations discussed in [RFC8279]
   and [RFC8296].  Another general security aspect results from using
   active OAM protocols ([RFC7799]) in a multicast network.

   Active OAM protocols inject specially constructed test packets.  Some
   active OAM protocols are based on the echo request/reply principle of
   using those test packets.  In the multicast network, test packets are
   replicated as data packets, thus creating a possible amplification
   effect of multiple echo replies being transmitted to the sender of
   the echo request.  Thus, following security-related requirements for
   BIER OAM:

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   *  A BIER OAM solution MUST protect the control plane by controlling
      the rate of echo request transmission.

   *  A BIER OAM solution MUST provide control of the number of BIER OAM
      messages sent to the control plane.

5.  Acknowledgements

   The authors would like to thank the comments and suggestions from
   Gunter van de Velde that helped improve this document.

6.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC6374]  Frost, D. and S. Bryant, "Packet Loss and Delay
              Measurement for MPLS Networks", RFC 6374,
              DOI 10.17487/RFC6374, September 2011,
              <https://www.rfc-editor.org/info/rfc6374>.

   [RFC7799]  Morton, A., "Active and Passive Metrics and Methods (with
              Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799,
              May 2016, <https://www.rfc-editor.org/info/rfc7799>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8279]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
              Explicit Replication (BIER)", RFC 8279,
              DOI 10.17487/RFC8279, November 2017,
              <https://www.rfc-editor.org/info/rfc8279>.

   [RFC8296]  Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
              Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
              for Bit Index Explicit Replication (BIER) in MPLS and Non-
              MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
              2018, <https://www.rfc-editor.org/info/rfc8296>.

7.  Informative References

   [RFC1191]  Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191,
              DOI 10.17487/RFC1191, November 1990,
              <https://www.rfc-editor.org/info/rfc1191>.

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   [RFC5860]  Vigoureux, M., Ed., Ward, D., Ed., and M. Betts, Ed.,
              "Requirements for Operations, Administration, and
              Maintenance (OAM) in MPLS Transport Networks", RFC 5860,
              DOI 10.17487/RFC5860, May 2010,
              <https://www.rfc-editor.org/info/rfc5860>.

   [RFC6291]  Andersson, L., van Helvoort, H., Bonica, R., Romascanu,
              D., and S. Mansfield, "Guidelines for the Use of the "OAM"
              Acronym in the IETF", BCP 161, RFC 6291,
              DOI 10.17487/RFC6291, June 2011,
              <https://www.rfc-editor.org/info/rfc6291>.

   [RFC6371]  Busi, I., Ed. and D. Allan, Ed., "Operations,
              Administration, and Maintenance Framework for MPLS-Based
              Transport Networks", RFC 6371, DOI 10.17487/RFC6371,
              September 2011, <https://www.rfc-editor.org/info/rfc6371>.

   [RFC6427]  Swallow, G., Ed., Fulignoli, A., Ed., Vigoureux, M., Ed.,
              Boutros, S., and D. Ward, "MPLS Fault Management
              Operations, Administration, and Maintenance (OAM)",
              RFC 6427, DOI 10.17487/RFC6427, November 2011,
              <https://www.rfc-editor.org/info/rfc6427>.

   [RFC6428]  Allan, D., Ed., Swallow, G., Ed., and J. Drake, Ed.,
              "Proactive Connectivity Verification, Continuity Check,
              and Remote Defect Indication for the MPLS Transport
              Profile", RFC 6428, DOI 10.17487/RFC6428, November 2011,
              <https://www.rfc-editor.org/info/rfc6428>.

   [RFC7276]  Mizrahi, T., Sprecher, N., Bellagamba, E., and Y.
              Weingarten, "An Overview of Operations, Administration,
              and Maintenance (OAM) Tools", RFC 7276,
              DOI 10.17487/RFC7276, June 2014,
              <https://www.rfc-editor.org/info/rfc7276>.

   [RFC8562]  Katz, D., Ward, D., Pallagatti, S., Ed., and G. Mirsky,
              Ed., "Bidirectional Forwarding Detection (BFD) for
              Multipoint Networks", RFC 8562, DOI 10.17487/RFC8562,
              April 2019, <https://www.rfc-editor.org/info/rfc8562>.

   [RFC8762]  Mirsky, G., Jun, G., Nydell, H., and R. Foote, "Simple
              Two-Way Active Measurement Protocol", RFC 8762,
              DOI 10.17487/RFC8762, March 2020,
              <https://www.rfc-editor.org/info/rfc8762>.

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   [RFC8972]  Mirsky, G., Min, X., Nydell, H., Foote, R., Masputra, A.,
              and E. Ruffini, "Simple Two-Way Active Measurement
              Protocol Optional Extensions", RFC 8972,
              DOI 10.17487/RFC8972, January 2021,
              <https://www.rfc-editor.org/info/rfc8972>.

   [RFC9341]  Fioccola, G., Ed., Cociglio, M., Mirsky, G., Mizrahi, T.,
              and T. Zhou, "Alternate-Marking Method", RFC 9341,
              DOI 10.17487/RFC9341, December 2022,
              <https://www.rfc-editor.org/info/rfc9341>.

   [RFC9342]  Fioccola, G., Ed., Cociglio, M., Sapio, A., Sisto, R., and
              T. Zhou, "Clustered Alternate-Marking Method", RFC 9342,
              DOI 10.17487/RFC9342, December 2022,
              <https://www.rfc-editor.org/info/rfc9342>.

   [RFC9780]  Mirsky, G., Mishra, G., and D. Eastlake 3rd,
              "Bidirectional Forwarding Detection (BFD) for Multipoint
              Networks over Point-to-Multipoint MPLS Label Switched
              Paths (LSPs)", RFC 9780, DOI 10.17487/RFC9780, May 2025,
              <https://www.rfc-editor.org/info/rfc9780>.

Contributors' Addresses

   Erik Nordmark
   Email: nordmark@acm.org

   Sam Aldrin
   Google
   Email: aldrin.ietf@gmail.com

   Lianshu Zheng
   Email: veronique_cheng@hotmail.com

   Nobo Akiya
   Email: nobo.akiya.dev@gmail.com

Authors' Addresses

   Greg Mirsky (editor)
   Ericsson
   Email: gregimirsky@gmail.com

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   Nagendra Kumar
   Oracle
   Email: nagendrakumar.nainar@gmail.com

   Mach Chen
   Huawei Technologies
   Email: mach.chen@huawei.com

   Santosh Pallagatti (editor)
   VMware
   Email: santosh.pallagatti@gmail.com

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