Encapsulation For MPLS Performance Measurement with Alternate-Marking Method
draft-ietf-mpls-inband-pm-encapsulation-14

MPLS Working Group                                         W. Cheng, Ed.
Internet-Draft                                              China Mobile
Intended status: Standards Track                             X. Min, Ed.
Expires: 5 February 2025                                       ZTE Corp.
                                                                 T. Zhou
                                                                  Huawei
                                                                  J. Dai
                                                               FiberHome
                                                                Y. Peleg
                                                                Broadcom
                                                           4 August 2024

 Encapsulation For MPLS Performance Measurement with Alternate-Marking
                                 Method
               draft-ietf-mpls-inband-pm-encapsulation-14

Abstract

   This document defines the encapsulation for MPLS performance
   measurement with the Alternate-Marking method, which performs flow-
   based packet loss, delay, and jitter measurements on the MPLS
   traffic.

Status of This Memo

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   This Internet-Draft will expire on 5 February 2025.

Copyright Notice

   Copyright (c) 2024 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
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   Please review these documents carefully, as they describe your rights
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions Used in This Document . . . . . . . . . . . . . .   3
     2.1.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   3.  Flow-based PM Encapsulation in MPLS . . . . . . . . . . . . .   4
     3.1.  Examples for Applying Flow-ID Label in a label stack  . .   6
   4.  Procedures of Encapsulation, Look-up and Decapsulation  . . .   8
   5.  Procedures of Flow-ID allocation  . . . . . . . . . . . . . .   9
   6.  FLC and FRLD Considerations . . . . . . . . . . . . . . . . .  10
   7.  Equal-Cost Multipath Considerations . . . . . . . . . . . . .  11
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   9.  Implementation Status . . . . . . . . . . . . . . . . . . . .  11
     9.1.  Fiberhome . . . . . . . . . . . . . . . . . . . . . . . .  12
     9.2.  Huawei Technologies . . . . . . . . . . . . . . . . . . .  12
     9.3.  ZTE Corp  . . . . . . . . . . . . . . . . . . . . . . . .  13
     9.4.  China Mobile  . . . . . . . . . . . . . . . . . . . . . .  13
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  14
   12. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  14
   13. References  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     13.1.  Normative References . . . . . . . . . . . . . . . . . .  14
     13.2.  Informative References . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  16

1.  Introduction

   [RFC9341] describes a performance measurement method, which can be
   used to measure packet loss, delay, and jitter on data traffic.
   Since this method is based on marking consecutive batches of packets,
   it is referred to as the Alternate-Marking Method.  [RFC8372]
   discusses aspects to consider when developing a solution for MPLS
   flow identification for performance monitoring of MPLS flows.

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   This document defines the encapsulation for MPLS performance
   measurement with the Alternate-Marking method, which performs flow-
   based packet loss, delay, and jitter measurements on the MPLS
   traffic.  The encapsulation defined in this document supports
   performance monitoring at the intermediate nodes and MPLS flow
   identification at both transport and service layers.

   Note that in parallel to the work of this document, there is ongoing
   work on MPLS Network Actions (MNA) [I-D.ietf-mpls-mna-fwk].
   Considering the MPLS performance measurement with the Alternate-
   Marking method can also be achieved by MNA encapsulation, it is
   agreed that this document will be made Historic once the MNA solution
   of performance measurement with the Alternate-Marking method is
   published as an RFC.

2.  Conventions Used in This Document

2.1.  Abbreviations

   ACL: Access Control List

   BoS: Bottom of Stack

   cSPL: Composite Special Purpose Label

   ECMP: Equal-Cost Multipath

   DSCP: Differentiated Services Code Point

   ELC: Entropy Label Capability

   ERLD: Entropy Readable Label Depth

   eSPL: Extended Special Purpose Label

   FL: Flow-ID Label

   FLC: Flow-ID Label Capability

   FLI: Flow-ID Label Indicator

   FRLD: Flow-ID Readable Label Depth

   IPFIX: IP Flow Information Export

   LSP: Label Switched Path

   MNA: MPLS Network Actions

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   MPLS: Multi-Protocol Label Switching

   NMS: Network Management System

   PHP: Penultimate Hop Popping

   PM: Performance Measurement

   PW: PseudoWire

   SFL: Synonymous Flow Label

   SID: Segment ID

   SR: Segment Routing

   TC: Traffic Class

   TTL: Time to Live

   VC: Virtual Channel

   VPN: Virtual Private Network

   XL: Extension Label

2.2.  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.

3.  Flow-based PM Encapsulation in MPLS

   Flow-based MPLS performance measurement encapsulation with the
   Alternate-Marking method has the following format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Extension Label (15)         |  TC |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Flow-ID Label Indicator (TBA1)    |  TC |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             Flow-ID Label             |L|D|T|S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

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               Figure 1: Flow-based PM Encapsulation in MPLS

   The Flow-ID Label Indicator (FLI) is an Extended Special Purpose
   Label (eSPL), which is combined with the Extension Label (XL, value
   15) to form a Composite Special Purpose Label (cSPL), as defined in
   [RFC9017].  The FLI is defined in this document as value TBA1.

   The Traffic Class (TC) and Time To Live (TTL) [RFC3032] for the XL
   and FLI MUST use the same field values as the label immediately
   preceding the XL. unless it is known that the XL will not be exposed
   as the top label at any point along the LSP.  In this case the TC and
   TTL for the XL and FLI MAY be of different values.  The Bottom of the
   Stack (BoS) bit [RFC3032] for the XL and FLI MUST be zero.

   The Flow-ID Label (FL) is used as an MPLS flow identification
   [RFC8372].  Its value MUST be unique within the administrative
   domain.  The Flow-ID Label values MAY be allocated by an external NMS
   or controller based on the measurement object instances (such as LSP
   or PW).  There is a one-to-one mapping between a Flow-ID and a flow.
   The specific method on how to allocate the Flow-ID Label values is
   described in Section 5.

   The FL, preceded by a cSPL, can be placed either at the bottom or in
   the middle, but not at the top, of the MPLS label stack, and it MAY
   appear multiple times within a label stack.  Section 3.1 of this
   document provides several examples to illustrate the application of
   FL in a label stack.  The TTL for the FL MUST be zero to ensure that
   it is not used inadvertently for forwarding.  The BoS bit for the FL
   depends on whether the FL is placed at the bottom of the MPLS label
   stack, i.e., the BoS bit for the FL is set only when the FL is placed
   at the bottom of the MPLS label stack.

   Besides the flow identification, a color-marking field is also
   necessary for the Alternate-Marking method.  To achieve the purpose
   of coloring the MPLS traffic, and to distinguish between hop-by-hop
   measurement and edge-to-edge measurement, the TC for the FL is
   defined as follows:

   *  L(oss) bit is used for coloring the MPLS packets for loss
      measurement.  Setting the bit means color 1 and unsetting the bit
      means color 0.

   *  D(elay) bit is used for coloring the MPLS packets for delay/jitter
      measurement.  Setting the bit means color for delay measurement.

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   *  T(ype) bit is used to indicate the measurement type.  When the T
      bit is set to 1, that means edge-to-edge performance measurement.
      When the T bit is set to 0, that means hop-by-hop performance
      measurement.

3.1.  Examples for Applying Flow-ID Label in a label stack

   Three examples of different layouts of the Flow-ID label (4 octets)
   are illustrated as follows.  Note that more examples may exist.

   (1) Layout of the Flow-ID label when applied to MPLS transport.

                +----------------------+
                |          LSP         |
                |         Label        |
                +----------------------+ <--+
                |       Extension      |    |
                |         Label        |    |
                +----------------------+    |--- cSPL
                |     Flow-ID Label    |    |
                |       Indicator      |    |
                +----------------------+ <--+
                |        Flow-ID       |
                |         Label        |
                +----------------------+
                |      Application     |
                |         Label        |
                +----------------------+ <= Bottom of stack
                |                      |
                |        Payload       |
                |                      |
                +----------------------+

                Figure 2: Applying Flow-ID to MPLS transport

   Note that here if the penultimate hop popping (PHP) is in use, the
   PHP LSR that recognizes the cSPL MUST NOT pop the cSPL and the
   following Flow-ID label, otherwise the egress LSR would be excluded
   from the performance measurement.

   Also note that in other examples of applying Flow-ID to MPLS
   transport, one LSP label can be substituted by multiple SID labels in
   the case of using SR Policy, and the combination of cSPL and Flow-ID
   label can be placed between SID labels, as specified in Section 6.

   (2) Layout of the Flow-ID label when applied to MPLS service.

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                +----------------------+
                |          LSP         |
                |         Label        |
                +----------------------+
                |      Application     |
                |         Label        |
                +----------------------+ <--+
                |       Extension      |    |
                |         Label        |    |
                +----------------------+    |--- cSPL
                |     Flow-ID Label    |    |
                |       Indicator      |    |
                +----------------------+ <--+
                |        Flow-ID       |
                |         Label        |
                +----------------------+ <= Bottom of stack
                |                      |
                |        Payload       |
                |                      |
                +----------------------+

                 Figure 3: Applying Flow-ID to MPLS service

   Note that in this case, the application label can be an MPLS PW
   label, MPLS Ethernet VPN label or MPLS IP VPN label, and it is also
   called a VC label as defined in [RFC4026].

   (3) Layout of the Flow-ID label when applied to both MPLS transport
   and MPLS service.

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                +----------------------+
                |          LSP         |
                |         Label        |
                +----------------------+ <--+
                |       Extension      |    |
                |         Label        |    |
                +----------------------+    |--- cSPL
                |     Flow-ID Label    |    |
                |       Indicator      |    |
                +----------------------+ <--+
                |        Flow-ID       |
                |         Label        |
                +----------------------+
                |      Application     |
                |         Label        |
                +----------------------+ <--+
                |       Extension      |    |
                |         Label        |    |
                +----------------------+    |--- cSPL
                |     Flow-ID Label    |    |
                |       Indicator      |    |
                +----------------------+ <--+
                |        Flow-ID       |
                |         Label        |
                +----------------------+ <= Bottom of stack
                |                      |
                |        Payload       |
                |                      |
                +----------------------+

     Figure 4: Applying Flow-ID to both MPLS transport and MPLS service

   Note that for this example, the two Flow-ID Label values appearing in
   a label stack MUST be different.  In other words, the Flow-ID label
   applied to the MPLS transport and the Flow-ID label applied to the
   MPLS service MUST be different.  Also, note that the two Flow-ID
   label values are independent of each other.  For example, two packets
   can belong to the same VPN flow but different LSP flows, or two
   packets can belong to different VPN flows but the same LSP flow.

4.  Procedures of Encapsulation, Look-up and Decapsulation

   The procedures for Flow-ID label encapsulation, look-up and
   decapsulation are summarized as follows:

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   *  The MPLS ingress node [RFC3031] inserts the XL, FLI and FL into
      the MPLS label stack.  At the same time, the ingress node sets the
      Flow-ID Label value, the two color-marking bits and the T bit, as
      defined in Section 3.

   *  If the edge-to-edge measurement is applied, i.e., the T bit is set
      to 1, then only the MPLS ingress/egress node [RFC3031] is the
      processing node, otherwise all the MPLS nodes along the LSP are
      the processing nodes.  The processing node looks up the FL with
      the help of the XL and FLI, and exports the collected data, such
      as the Flow-ID, block counters and timestamps, to an external NMS/
      controller, referring to the Alternate-Marking method.  Section 6
      of [I-D.ietf-ippm-alt-mark-deployment] describes protocols for
      collected data export, and the details on how to export the
      collected data are outside the scope of this document.  Note that
      while looking up the Flow-ID label, the transit node needs to
      perform some deep packet inspection beyond the label (at the top
      of the label stack) used to make forwarding decisions.

   *  The processing node MUST pop the XL, FLI and FL from the MPLS
      label stack when it needs to pop the preceding forwarding label.
      The egress node MUST pop the whole MPLS label stack, and this
      document doesn't introduce any new process to the decapsulated
      packet.

5.  Procedures of Flow-ID allocation

   There are at least two ways of allocating Flow-ID.  One way is to
   allocate Flow-ID by a manual trigger from the network operator, and
   the other way is to allocate Flow-ID by an automatic trigger from the
   ingress node.  Details are as follows:

   *  In the case of a manual trigger, the network operator would
      manually input the characteristics (e.g.  IP five tuples and IP
      DSCP) of the measured flow, then the NMS/controller would generate
      one or two Flow-IDs based on the input from the network operator,
      and provision the ingress node with the characteristics of the
      measured flow and the corresponding allocated Flow-ID(s).

   *  In the case of an automatic trigger, the ingress node would
      identify the flow entering the measured path, export the
      characteristics of the identified flow to the NMS/controller by
      IPFIX [RFC7011], then the NMS/controller would generate one or two
      Flow-IDs based on the characteristics exported from the ingress
      node, and provision the ingress node with the characteristics of
      the identified flow and the corresponding allocated Flow-ID(s).

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   The policy pre-configured at the NMS/controller decides whether one
   Flow-ID or two Flow-IDs would be generated.  If the performance
   measurement on the MPLS service is enabled, then one Flow-ID applied
   to the MPLS service would be generated.  If the performance
   measurement on the MPLS transport is enabled, then one Flow-ID
   applied to the MPLS transport would be generated.  If both of them
   are enabled, then two Flow-IDs are respectively applied to the MPLS
   service and the MPLS transport would be generated.  In this case, the
   transit node needs to look up both of the two Flow-IDs by default.
   However, this behaviour can be changed through configuration, such as
   by setting it to look up only the Flow-ID applied to the MPLS
   transport.

   Whether using the two methods mentioned above or other methods to
   allocate Flow-ID, the NMS/controller MUST ensure that every generated
   Flow-ID is unique within the administrative domain and MUST NOT have
   any value in the reserved label space (0-15) [RFC3032].

6.  FLC and FRLD Considerations

   Analogous to the Entropy Label Capability (ELC) defined in Section 5
   of [RFC6790] and the Entropy Readable Label Depth (ERLD) defined in
   Section 4 of [RFC8662], the Flow-ID Label Capability (FLC) and the
   Flow-ID Readable Label Depth (FRLD) are defined in this document.
   Both FLC and FRLD have similar semantics with the ELC and ERLD to a
   router, except that the Flow-ID is used in its flow identification
   function while the Entropy is used in its load-balancing function.

   The ingress node MUST insert each FL at an appropriate depth, which
   ensures the node to which the FL is exposed has the FLC.  The ingress
   node SHOULD insert each FL within an appropriate FRLD, which is the
   minimum FRLD of all the on-path nodes that need to read and use the
   FL in question.  How the ingress node knows the FLC and FRLD of all
   the on-path nodes is outside the scope of this document.  However,
   [I-D.xzc-lsr-mpls-flc-frld] provides a method to achieve this.

   When the SR paths are used for transport, the label stack grows as
   the number of on-path segments increases.  If the number of on-path
   segments is high, that may become a challenge for the FL to be placed
   within an appropriate FRLD.  To overcome this potential challenge, an
   implementation MAY allow the ingress node to place FL between SID
   labels.  This means that multiple identical FLs at different depths
   MAY be interleaved with SID labels.  When this occurs, sophisticated
   network planning may be needed, which is beyond the scope of this
   document.

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7.  Equal-Cost Multipath Considerations

   Analogous to what's described in Section 5 of [RFC8957], under
   conditions of Equal-Cost Multipath (ECMP), the introduction of the FL
   may lead to the same problem as caused by the Synonymous Flow Label
   (SFL).  The two solutions proposed for SFL would also apply here.
   Specifically, adding FL to an existing flow may cause that flow to
   take a different path.  If the operator expects to resolve this
   problem, they can choose to apply entropy labels [RFC6790] or add FL
   to all flows.

8.  Security Considerations

   As specified in Section 3, the value of a Flow-ID label MUST be
   unique within the administrative domain.  In other words, the
   administrative domain is the scope of a Flow-ID label.  The method
   for achieving multi-domain performance measurement with the same
   Flow-ID label is outside the scope of this document.  The Flow-ID
   label MUST NOT be signaled and distributed outside the administrative
   domain.  Improper configuration that allows the Flow-ID label to be
   passed from one administrative domain to another would result in
   Flow-ID conflicts.

   To prevent packets carrying Flow-ID labels from leaking from one
   domain to another, domain boundary nodes SHOULD deploy policies
   (e.g., ACL) to filter out these packets.  Specifically, at the
   sending edge, the domain boundary node SHOULD filter out the packets
   that carry the Flow-ID Label Indicator and are sent to other domains.
   At the receiving edge, the domain boundary node SHOULD drop the
   packets that carry the Flow-ID Label Indicator and are from other
   domains.

9.  Implementation Status

   [Note to the RFC Editor - remove this section before publication, as
   well as remove the reference to [RFC7942].

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   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   The description of implementations in this section is intended to
   assist the IETF in its decision processes in progressing drafts to
   RFCs.  Please note that the listing of any individual implementation
   here does not imply endorsement by the IETF.  Furthermore, no effort
   has been spent to verify the information presented here that was
   supplied by IETF contributors.  This is not intended as, and must not
   be construed to be, a catalog of available implementations or their
   features.  Readers are advised to note that other implementations may
   exist.

   According to [RFC7942], "this will allow reviewers and working groups
   to assign due consideration to documents that have the benefit of
   running code, which may serve as evidence of valuable experimentation
   and feedback that have made the implemented protocols more mature.
   It is up to the individual working groups to use this information as
   they see fit".

9.1.  Fiberhome

   *  Organization: Fiberhome Corporation.

   *  Implementation: Fiberhome R82*, R800*, S680*, S780* series routers
      are running the common-building block 'Flow-based PM Encapsulation
      in MPLS'.

   *  Maturity Level: Product

   *  Coverage: Partial, section 3 and example (2) of section 3.1.

   *  Version: Draft-08

   *  Licensing: N/A

   *  Implementation experience: Nothing specific.

   *  Contact: djy@fiberhome.com

   *  Last updated: December 25, 2023

9.2.  Huawei Technologies

   *  Organization: Huawei Technologies.

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   *  Implementation: Huawei ATN8XX, ATN910C, ATN980B, CX600-M2, NE40E,
      ME60-X1X2, ME60-X3X8X16 Routers running VRPV800R021C00 or above.
      Huawei NCE-IP Controller running V1R21C00 or above.

   *  Maturity Level: Product

   *  Coverage: Partial, section 3 and example (2) of section 3.1.

   *  Version: Draft-08

   *  Licensing: N/A

   *  Implementation experience: Nothing specific.

   *  Contact: zhoutianran@huawei.com

   *  Last updated: January 10, 2024

9.3.  ZTE Corp

   *  Organization: ZTE Corporation.

   *  Implementation: ZTE ZXCTN 6500-32 routers running V5.00.20 or
      above.  ZTE ZXCTN 6170H routers running V5.00.30.20 or above.  ZTE
      ElasticNet UME Controller running V16.22.20 or above.

   *  Maturity Level: Product

   *  Coverage: Partial, section 3 and example (2) of section 3.1.

   *  Version: Draft-08

   *  Licensing: N/A

   *  Implementation experience: Nothing specific.

   *  Contact: xiao.min2@zte.com.cn

   *  Last updated: January 22, 2024

9.4.  China Mobile

   China Mobile reported that they have conducted interconnection tests
   with multiple vendors according to this draft.  The tests result have
   proven that the solutions from multiple vendors are mature and ready
   for large-scale deployment.  This report was last updated on January
   10, 2024.

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10.  IANA Considerations

   From the "Extended Special-Purpose MPLS Label Values" registry in the
   "Special-Purpose Multiprotocol Label Switching (MPLS) Label Values"
   namespace, a new value for the Flow-ID Label Indicator is requested
   from IANA as follows:

     +================================+=================+===========+
     | Value                          | Description     | Reference |
     +================================+=================+===========+
     | TBA1 (value 18 is recommended) | Flow-ID Label   | This      |
     |                                | Indicator (FLI) | Document  |
     +--------------------------------+-----------------+-----------+

        Table 1: New Extended Special-Purpose MPLS Label Value for
                         Flow-ID Label Indicator

11.  Acknowledgements

   The authors would like to acknowledge Loa Andersson, Tarek Saad,
   Stewart Bryant, Rakesh Gandhi, Greg Mirsky, Aihua Liu, Shuangping
   Zhan, Ming Ke, Wei He, Ximing Dong, Darren Dukes, Tony Li, and James
   Guichard for their careful review and very helpful comments.

   They also wish to acknowledge Italo Busi and Chandrasekar
   Ramachandran for their insightful MPLS-RT review and constructive
   comments.

   Additionally, the authors would like to thank Dhruv Dhody for the
   English grammar review.

12.  Contributors

   Minxue Wang
   China Mobile
   Email: wangminxue@chinamobile.com

   Wen Ye
   China Mobile
   Email: yewen@chinamobile.com

13.  References

13.1.  Normative References

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   [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>.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031,
              DOI 10.17487/RFC3031, January 2001,
              <https://www.rfc-editor.org/info/rfc3031>.

   [RFC3032]  Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
              Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
              Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001,
              <https://www.rfc-editor.org/info/rfc3032>.

   [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>.

   [RFC9017]  Andersson, L., Kompella, K., and A. Farrel, "Special-
              Purpose Label Terminology", RFC 9017,
              DOI 10.17487/RFC9017, April 2021,
              <https://www.rfc-editor.org/info/rfc9017>.

13.2.  Informative References

   [I-D.ietf-ippm-alt-mark-deployment]
              Fioccola, G., Keyi, Z., Graf, T., Nilo, M., and L. Zhang,
              "Alternate Marking Deployment Framework", Work in
              Progress, Internet-Draft, draft-ietf-ippm-alt-mark-
              deployment-01, 3 July 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-ippm-
              alt-mark-deployment-01>.

   [I-D.ietf-mpls-mna-fwk]
              Andersson, L., Bryant, S., Bocci, M., and T. Li, "MPLS
              Network Actions (MNA) Framework", Work in Progress,
              Internet-Draft, draft-ietf-mpls-mna-fwk-09, 19 June 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-mpls-
              mna-fwk-09>.

   [I-D.xzc-lsr-mpls-flc-frld]
              Min, X., Zhang, Z., and W. Cheng, "Signaling Flow-ID Label
              Capability and Flow-ID Readable Label Depth", Work in
              Progress, Internet-Draft, draft-xzc-lsr-mpls-flc-frld-04,
              28 January 2024, <https://datatracker.ietf.org/doc/html/
              draft-xzc-lsr-mpls-flc-frld-04>.

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   [RFC4026]  Andersson, L. and T. Madsen, "Provider Provisioned Virtual
              Private Network (VPN) Terminology", RFC 4026,
              DOI 10.17487/RFC4026, March 2005,
              <https://www.rfc-editor.org/info/rfc4026>.

   [RFC6790]  Kompella, K., Drake, J., Amante, S., Henderickx, W., and
              L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
              RFC 6790, DOI 10.17487/RFC6790, November 2012,
              <https://www.rfc-editor.org/info/rfc6790>.

   [RFC7011]  Claise, B., Ed., Trammell, B., Ed., and P. Aitken,
              "Specification of the IP Flow Information Export (IPFIX)
              Protocol for the Exchange of Flow Information", STD 77,
              RFC 7011, DOI 10.17487/RFC7011, September 2013,
              <https://www.rfc-editor.org/info/rfc7011>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/info/rfc7942>.

   [RFC8372]  Bryant, S., Pignataro, C., Chen, M., Li, Z., and G.
              Mirsky, "MPLS Flow Identification Considerations",
              RFC 8372, DOI 10.17487/RFC8372, May 2018,
              <https://www.rfc-editor.org/info/rfc8372>.

   [RFC8662]  Kini, S., Kompella, K., Sivabalan, S., Litkowski, S.,
              Shakir, R., and J. Tantsura, "Entropy Label for Source
              Packet Routing in Networking (SPRING) Tunnels", RFC 8662,
              DOI 10.17487/RFC8662, December 2019,
              <https://www.rfc-editor.org/info/rfc8662>.

   [RFC8957]  Bryant, S., Chen, M., Swallow, G., Sivabalan, S., and G.
              Mirsky, "Synonymous Flow Label Framework", RFC 8957,
              DOI 10.17487/RFC8957, January 2021,
              <https://www.rfc-editor.org/info/rfc8957>.

   [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>.

Authors' Addresses

   Weiqiang Cheng (editor)
   China Mobile
   Beijing
   China

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   Email: chengweiqiang@chinamobile.com

   Xiao Min (editor)
   ZTE Corp.
   Nanjing
   China
   Email: xiao.min2@zte.com.cn

   Tianran Zhou
   Huawei
   Beijing
   China
   Email: zhoutianran@huawei.com

   Jinyou Dai
   FiberHome
   Wuhan
   China
   Email: djy@fiberhome.com

   Yoav Peleg
   Broadcom
   United States of America
   Email: yoav.peleg@broadcom.com

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