MPLS Alternate Marking: Encapsulation for MPLS Performance Measurement with the Alternate-Marking Method

Internet Engineering Task Force (IETF)                     W. Cheng, Ed.
Request for Comments: 9714                                  China Mobile
Category: Standards Track                                    X. Min, Ed.
ISSN: 2070-1721                                                ZTE Corp.
                                                                 T. Zhou
                                                                  Huawei
                                                                  J. Dai
                                                               FiberHome
                                                                Y. Peleg
                                                                Broadcom
                                                           February 2025


   Encapsulation for MPLS Performance Measurement with the Alternate-
                             Marking Method

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 MPLS traffic.

Status of This Memo

   This is an Internet Standards Track document.

   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).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc9714.

Copyright Notice

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

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Table of Contents

   1.  Introduction
   2.  Conventions Used in This Document
     2.1.  Abbreviations
     2.2.  Requirements Language
   3.  Flow-Based PM Encapsulation in MPLS
     3.1.  Examples for Applying Flow-ID Label in a Label Stack
       3.1.1.  Layout of the Flow-ID Label when Applied to MPLS
               Transport
       3.1.2.  Layout of the Flow-ID Label when Applied to MPLS
               Service
       3.1.3.  Layout of the Flow-ID Label when Applied to both MPLS
               Transport and MPLS Service
   4.  Procedures of Encapsulation, Look-Up, and Decapsulation
   5.  Procedures of Flow-ID Allocation
   6.  FLC and FRLD Considerations
   7.  Equal-Cost Multipath Considerations
   8.  Security Considerations
   9.  IANA Considerations
   10. References
     10.1.  Normative References
     10.2.  Informative References
   Acknowledgements
   Contributors
   Authors' Addresses

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]
   outlines key considerations for developing a solution for MPLS flow
   identification, intended for use in performance monitoring of MPLS
   flows.

   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, at the time of writing, there is ongoing work on MPLS
   Network Actions (MNAs) [RFC9613].  The MPLS performance measurement
   with the Alternate-Marking Method can also be achieved by MNA
   encapsulation.  In addition, MNA will provide a broader use-case
   applicability.  That means the MNA encapsulation is expected to
   provide a more advanced solution.  The MPLS Working Group has agreed
   that this document will be made Historic when that solution 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, the combination of the
      Extension Label (value 15) and an Extended Special Purpose Label

   DSCP:  Differentiated Services Code Point

   ELC:  Entropy Label Capability

   ERLD:  Entropy Readable Label Depth

   eSPL:  Extended Special Purpose Label, a special-purpose label that
      is placed in the label stack after the Extension Label (value 15)

   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 [RFC7011]

   LSP:  Label Switched Path

   LSR:  Label Switching Router

   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

   This document defines the Flow-based MPLS performance measurement
   encapsulation with the Alternate-Marking Method, as shown in
   Figure 1.

    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 (18)      |  TC |S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             Flow-ID Label             |L|D|T|S|      TTL      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               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 18.

   The Traffic Class (TC) and Time To Live (TTL) fields of the XL and
   FLI MUST use the same values of the label immediately preceding the
   XL.  The Bottom of the Stack (BoS) bit [RFC3032] for the XL and FLI
   MUST be zero.  If any XL or FLI processed by a node has the BoS bit
   set, the node MUST discard the packet and MAY log an error.

   The Flow-ID Label (FL) is used as an MPLS flow identification
   [RFC8372].  Its value MUST be unique within the administrative
   domain.  The FL 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 FL 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 color 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.

   *  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.

   Considering the FL is not used as a forwarding label, the repurposing
   of the TC for the FL is feasible and viable.

3.1.  Examples for Applying Flow-ID Label in a Label Stack

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

3.1.1.  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

   With penultimate hop popping (PHP Section 3.16 of [RFC3031]), the top
   label is "popped at the penultimate LSR of the LSP, rather than at
   the LSP Egress".  The final bullet of Section 4 of the present
   document requires that "[t]he processing node MUST pop the XL, FLI,
   and FL from the MPLS label stack when it needs to pop the preceding
   forwarding label", which implies that the penultimate Label Switching
   Router (LSR) needs to follow the requirement of Section 4 in order to
   support this specification.  If this is done, the egress LSR is
   excluded from the performance measurement.  Therefore, when this
   specification is in use, PHP should be disabled, unless the
   penultimate LSR is known to have the necessary support and unless
   it's acceptable to exclude the egress LSR.

   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 FL can
   be placed between SID labels, as specified in Section 6.

3.1.2.  Layout of the Flow-ID Label when Applied to MPLS Service

                +----------------------+
                |          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].

3.1.3.  Layout of the Flow-ID Label when Applied to both MPLS Transport
        and MPLS Service

                +----------------------+
                |          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 FL values appearing in a label
   stack must be different.  In other words, the FL applied to the MPLS
   transport and the FL applied to the MPLS service must be different.
   Also, note that the two FL 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 FL encapsulation, look-up, and decapsulation are
   summarized as follows:

   *  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
      FL value, the two color-marking bits, and the T bit, as defined in
      Section 3.

   *  If 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 [ALT-MARK] describes protocols for collected data
      export; the details on how to export the collected data are
      outside the scope of this document.  Note that while looking up
      the FL, the transit node needs to inspect 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.  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 manually
      inputs the characteristics (e.g., IP five tuples and IP DSCP) of
      the measured flow; then the NMS/controller generates one or two
      Flow-IDs based on the input from the network operator and
      provisions 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 identifies
      the flow entering the measured path and exports the
      characteristics of the identified flow to the NMS/controller by
      IPFIX [RFC7011]; then the NMS/controller generates one or two
      Flow-IDs based on the characteristics exported from the ingress
      node and provisions the ingress node with the characteristics of
      the identified flow and the corresponding allocated Flow-ID(s).

   The policy preconfigured at the NMS/controller decides whether one
   Flow-ID or two Flow-IDs are generated.  If the performance
   measurement on the MPLS service is enabled, then one Flow-ID applied
   to the MPLS service is generated.  If the performance measurement on
   the MPLS transport is enabled, then one Flow-ID applied to the MPLS
   transport is generated.  If both of them are enabled, then two Flow-
   IDs are respectively applied to the MPLS service and the MPLS
   transport are generated.  In this case, a transit node needs to look
   up both of the two Flow-IDs by default.  However, this behavior 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].
   Specifically, the statement of "Flow-ID is unique" means that the
   values of Flow-ID are distinct and non-redundant for any flow at any
   given time within an administrative domain, such that no two flows
   share the same Flow-ID.  This uniqueness ensures that each flow can
   be individually identified, tracked, and differentiated from others
   for accurate performance monitoring and management.

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.

   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.

7.  Equal-Cost Multipath Considerations

   Analogous to what's described in Section 5 of [RFC8957], under
   conditions of equal-cost multipath, the introduction of the FL may
   lead to the same problem that is caused by the Synonymous Flow Label
   (SFL) [RFC8957].  The two solutions proposed for SFL 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 7.1 of [RFC9341], "for security reasons, the
   Alternate-Marking Method MUST only be applied to controlled domains."
   This requirement applies when the MPLS performance measurement with
   Alternate-Marking Method is taken into account, which means the MPLS
   encapsulation and related procedures defined in this document MUST
   only be applied to controlled domains; otherwise, the potential
   attacks discussed in Section 10 of [RFC9341] may be applied to the
   deployed MPLS networks.

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

   To prevent packets carrying FLs from leaking from one domain to
   another, domain boundary nodes MUST deploy policies (e.g., ACL) to
   filter out these packets.  Specifically, at the sending edge, the
   domain boundary node MUST filter out the packets that carry the FLI
   and are sent to other domains.  At the receiving edge, the domain
   boundary node MUST drop the packets that carry the FLI and are from
   other domains.  Note that packet leakage is neither breaching privacy
   nor a source of DoS.

9.  IANA Considerations

   IANA has assigned the following value in the "Extended Special-
   Purpose MPLS Label Values" registry within the "Special-Purpose
   Multiprotocol Label Switching (MPLS) Label Values" registry group:

           +=======+===============================+===========+
           | Value | Description                   | Reference |
           +=======+===============================+===========+
           | 18    | Flow-ID Label Indicator (FLI) | RFC 9714  |
           +-------+-------------------------------+-----------+

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

10.  References

10.1.  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>.

   [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>.

10.2.  Informative References

   [ALT-MARK] Fioccola, G., Zhu, K., Graf, T., Nilo, M., and L. Zhang,
              "Alternate Marking Deployment Framework", Work in
              Progress, Internet-Draft, draft-ietf-ippm-alt-mark-
              deployment-02, 9 October 2024,
              <https://datatracker.ietf.org/doc/html/draft-ietf-ippm-
              alt-mark-deployment-02>.

   [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>.

   [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>.

   [RFC9613]  Bocci, M., Ed., Bryant, S., and J. Drake, "Requirements
              for Solutions that Support MPLS Network Actions (MNAs)",
              RFC 9613, DOI 10.17487/RFC9613, August 2024,
              <https://www.rfc-editor.org/info/rfc9613>.

Acknowledgements

   The authors 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, James Guichard, Daniele
   Ceccarelli, Éric Vyncke, John Scudder, Gunter van de Velde, Roman
   Danyliw, Warren Kumari, Murray Kucherawy, Deb Cooley, Zaheduzzaman
   Sarker, and Deborah Brungard for their careful review and very
   helpful comments.

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

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

Contributors

   Minxue Wang
   China Mobile
   Email: wangminxue@chinamobile.com


   Wen Ye
   China Mobile
   Email: yewen@chinamobile.com


Authors' Addresses

   Weiqiang Cheng (editor)
   China Mobile
   Beijing
   China
   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