Network Topology data retrieval using ALTO protocol
draft-hzx-alto-network-topo-00

Document Type Active Internet-Draft (individual)
Authors Hanshu Hong  , Cheng Zhou  , Chongfeng Xie  , Qiufang Ma 
Last updated 2021-06-24
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Application-Layer Traffic Optimization                           H. Hong
Internet-Draft                                                    Huawei
Intended status: Informational                                   C. Zhou
Expires: December 26, 2021                                  China Mobile
                                                                  C. Xie
                                                           China Telecom
                                                                   Q. Ma
                                                                  Huawei
                                                           June 24, 2021

          Network Topology data retrieval using ALTO protocol
                     draft-hzx-alto-network-topo-00

Abstract

   RFC8345 introduces an abstract YANG data model to represent network
   topologies.  This document uses ALTO protocol to provide access to
   network Topology data such as L3 topology data , data center network
   topology data, flexible enough to enable querying of specific and
   possibly aggregated data.

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
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   This Internet-Draft will expire on December 26, 2021.

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   Copyright (c) 2021 IETF Trust and the persons identified as the
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   This document is subject to BCP 78 and the IETF Trust's Legal
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   publication of this document.  Please review these documents

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   carefully, as they describe your rights and restrictions with respect
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Solution Overview . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Translation of Structure of L3 Topo data to ALTO data format    4
   5.  Translation of Structure of L2 Topo data to ALTO data format    5
   6.  Translation of Structure of Data Fabric Topo data to ALTO
       data format . . . . . . . . . . . . . . . . . . . . . . . . .   7
   7.  Translation of Structure of VPN Performance Monitoring Data
       to ALTO data format . . . . . . . . . . . . . . . . . . . . .   8
   8.  Proposed ALTO protocol extension  . . . . . . . . . . . . . .  10
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     12.1.  Informative References . . . . . . . . . . . . . . . . .  10
     12.2.  Normative References . . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   This document uses ALTO protocol to provide access to network
   Topology data such as L3 topology data , Data Center Network Topology
   data, flexible enough to enable querying of specific and possibly
   aggregated data.  In addition, this document introduces a topology
   data translation mechanism which allow translation of structure of
   network topology data modeled in YANG to ALTO data format, which can
   be seen as a typical example of functional model of reference
   architecture of Digital Twin Network defined in [I-D.zhou-nmrg-
   digitaltwin-network-concepts].

   The concept of digital twin was proposed by Grieves in [Grieves2014].
   It is defined as a virtual representation that serves as the real-
   time digital counterpart of a physical entity and reflects the whole
   life-cycle device management.  A digital twin network graph is
   designed by digital twin platform and formulated by applying digital
   twin techniques to physical networks: it creates a virtual image of a
   physical network by using network data model technology.  The data
   model defined in [RFC8345] can be seen as basic model defined in [I-
   D.zhou-nmrg-digitaltwin-network-concepts] and is divided into two
   parts: The first part of the data model defines a network data model

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   that enables the definition of network hierarchies, or network stacks
   (i.e., networks that are layered on top of each other) and
   maintenance of an inventory of nodes contained in a network.  The
   second part of the data model augments the basic network data model
   with information to describe topology information.  Specifically, it
   adds the concepts of "links" and "termination points" to describe how
   nodes in a network are connected to each other.  Moreover, the data
   model introduces vertical layering relationships between networks
   that can be augmented to cover both network inventories and network/
   service topologies.  Note that functional model is a derived model
   from basic models defined in [I-D.zhou-nmrg-digitaltwin-network-
   concepts] and can be used to provide network analysis, simulation,
   diagnosis, prediction, assurance, etc.

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.  Solution Overview

   This document addresses how to retrieve potentially aggregated
   network topology data from topology manager using ALTO protocol for a
   certain network,e.g., Data Fabric network, layer 3 network, layer 2
   network.  These network topology data are collected by NETCONF client
   using NETCONF protocol [RFC6241] and Layer 3 topology YANG data model
   [RFC8345], Layer 2 topology YANG data model [RFC8944], data fabric
   topology YANG data model [RFC8542] and stored in the topo database
   within the Topolgy manager.  The Topology manager is comprised of
   four components: NETCONF client, Topology database, Topology data
   translation and ALTO server.

   The topology data translation component is used to translate
   structure of Topology data modeled in YANG into ALTO data object
   format.  ALTO server provides a query interface for topology data
   retrieval.  NETCONF client retrieves the network topology related
   data or network element related data from each Network Elements using
   NETCONF protocols or via other telemetry interface.  And the Topology
   database is fed by the NETCONF client with its retrieved data, as
   shown in below figure.

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      +-----------------------------------+
      |        Topology   Manager         |       +-------+
      |+-----------++---------+  +-------+|       |       |
      || Topo      ||  Topo   |  |ALTO   ||       | ALTO  |
      ||translation||database |  |Server ++-------+-Client|
      |+-----------++---------+  +-------+|       +-------+
      |          +---------+              |
      |          |NC Client|              |
      |          +-+----+--+              |
      +------------+----+-----------------+
                   |    |
              +----|    +---------+
              |                   |
       +------+---------+      +--+-------------+
       | +----+----+    |      | ++--------+    |
       | |NC Server|    |      | |NC Server|    |
       | +---------+    |      | +---------+    |
       |Network Element1|      |Network Element2|
       +----------------+      +----------------+

4.  Translation of Structure of L3 Topo data to ALTO data format

   The following table lists the ALTO data objects with corresponding
   objects in the L3 Topo YANG data model [RFC8345].  Note that the
   network topology data described in L3 Topo YANG data model represents
   aggregated topology information,i.e., overlay network topology
   information.

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   +----------------------------------+--------------------------------+
   | YANG data node in                | ALTO data object               |
   | /nw:networks/nw:network/         |                                |
   +----------------------------------+--------------------------------+
   |l3t:l3-topology-attributes/l3t:name network-map/resource-id        |
   |                                  |                                |
   |nw:node/l3t:l3-node-attributes    |                                |
   |   /l3t:name                      | network-map/PIDName            |
   |                                  |                                |
   |/nw:node/l3t:l3-node-attributes   |                                |
   |   /l3t:flag                      | network-map/PIDName.flag       |
   |                                  |                                |
   |/nw:node/l3t:l3-node-attributes   | network-map/PIDName            |
   |        /l3t:router-id            |       /EndpointAddrGroup       |
   |                                  |                                |
   |/nw:node/l3t:l3-node-attributes   | network-map/PIDName            |
   |       /l3t:prefix/l3t:prefix     |       /EndpointAddrGroup       |
   |                                  |                                |
   |/nw:node/l3t:l3-node-attributes   | network-map/PIDName            |
   |       /l3t:prefix/l3t:metric     |    /EndpointAddrGroup.metric   |
   |                                  |                                |
   |/nw:node/l3t:l3-node-attributes   | network-map/PIDName            |
   |        /l3t:prefix/l3t:flag      |      /EndpointAddrGroup.flag   |
   |                                  |                                |
   |/nw:link/l3t:l3-link-attributes   | network-map/PIDName            |
   |       /l3t:name                  |            /PIDName            |
   |                                  |                                |
   |/nw:link/l3t:l3-link-attributes   | network-map/PIDName            |
   |        /l3t:metric1              |        /PIDName/DstCost        |
   |                                  |                                |
   |/nw:link/l3t:l3-link-attributes   | network-map/PIDName            |
   |        /l3t:metric2              |        /PIDName/DstCost        |
   |                                  |                                |
   |/nw:link/l3t:l3-link-attributes   | network-map/PIDName            |
   |        /l3t:flag                 |           /PIDName.flag        |
   +----------------------------------+--------------------------------+

5.  Translation of Structure of L2 Topo data to ALTO data format

   The following table lists the ALTO data objects with corresponding
   objects in the L2 Topo YANG data model [RFC8944].  Note that the
   network topology data described in L2 Topo YANG data model represents
   aggregated topology information,i.e., overlay network topology
   information.

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   +----------------------------------+--------------------------------+
   | YANG data node in                | ALTO data object               |
   | /nw:networks/nw:network/         |                                |
   +----------------------------------+--------------------------------+
   |l2t:l2-topology-attributes/l2t:name network-map/resource-id        |
   |                                                                   |
   |nw:node/l2t:l2-node-attributes    |                                |
   |   /l2t:name                      | network-map/PIDName            |
   |                                                                   |
   |/nw:node/l2t:l2-node-attributes   |                                |
   |   /l2t:flag                      | network-map/PIDName.flag       |
   |                                                                   |
   |/nw:node/l2t:l2-node-attributes   | network-map/PIDName            |
   |        /l2t:bridge-id            | /EndpointAddrGroup(Not support)|
   |                                                                   |
   |/nw:node/l2t:l2-node-attributes   | network-map/PIDName            |
   |       /l2t:management-address    |   /EndpointAddrGroup           |
   |                                  |   .management-address          |
   |                                                                   |
   |/nw:node/l2t:l2-node-attributes   | network-map/PIDName            |
   |        /l2t:management-mac       |    /EndpointAddrGroup          |
   |                                  |     .management-mac            |
   |                                                                   |
   |/nw:node/l2t:l2-node-attributes   | network-map/PIDName            |
   |        /l2t:management-vlan      |     /EndpointAddrGroup         |
   |                                  |       .management-vlan         |
   |                                                                   |
   |/nw:link/l2t:l2-link-attributes   | network-map/PIDName            |
   |        /l2t:name                 |      /PIDName                  |
   |                                                                   |
   |/nw:link/l2t:l2-link-attributes   | network-map/PIDName            |
   |       /l2t:rate                  |        /PIDName/DstCost        |
   |                                                                   |
   |/nw:link/l2t:l2-link-attributes   | network-map/PIDName            |
   |       /l2t:rate                  |        /PIDName/DstCost        |
   |                                                                   |
   |/nw:link/l2t:l2-link-attributes   | network-map/PIDName            |
   |       /l2t:flag                  |           /PIDName.flag        |
   |                                                                   |
   |/nw:link/l2t:l2-link-attributes   | network-map/PIDName/           |
   |        /l2t:auto-nego            |            PIDName.auto-nego   |
   |                                                                   |
   |/nw:link/l2t:l2-link-attributes   | network-map/PIDName            |
   |        /l2t:duplex               |           /PIDName.duplex      |
   +----------------------------------+--------------------------------+

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6.  Translation of Structure of Data Fabric Topo data to ALTO data
    format

   The following table lists the ALTO data objects with corresponding
   objects in the Data Fabric Topo YANG data model [RFC8542].  Note that
   the network topology data described in Data Fabric Topo YANG data
   model represents aggregated topology information,i.e., overlay
   network topology information.

   +----------------------------------+--------------------------------+
   | YANG data node in                | ALTO data object               |
   | /nw:networks/nw:network/         |                                |
   +----------------------------------+--------------------------------+
   |/nw:node/fabric:fabric-attributes | network-map/PIDName            |
   |        /fabric:name              |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes | network-map/PIDName.type       |
   |        /fabric:type              |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes | network-map/PIDName.fabric-id  |
   |        /fabric:fabric-id         |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes | network-map/PIDName.description|
   |        /fabric:description       |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes | network-map/PIDName.options    |
   |/fabric:options/fabric:gateway-mode      .gateway-mode             |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes | network-map/PIDName.options    |
   |/fabric:options/fabric:           |       .traffic-behavior        |
   |       traffic-behavior           |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes | network-map/PIDName.options    |
   |/fabric:options/fabric:           |       .capability-support      |
   |   capability-support             |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-nodes|
   |/fabric:device-nodes/fabric:      |      .device-ref               |
   |      device-ref                  |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-nodes|
   |       /fabric:device-nodes       |          .role                 |
   |       /fabric:role               |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-links|
   |      /fabric:device-links        |          .link-ref             |
   |     /fabric:link-ref             |                                |
   |                                  |                                |

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   |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-ports|
   |      /fabric:device-ports        |          .port-ref             |
   |      /fabric:port-ref            |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-ports|
   |/fabric:device-ports              |      .port-type                |
   |/fabric:port-type                 |                                |
   |                                  |                                |
   |/nw:node/fabric:fabric-attributes |network-map/PIDName.device-ports|
   |/fabric:device-ports              |      .bandwidth                |
   |/fabric:bandwidth                 |                                |
   +----------------------------------+--------------------------------+

7.  Translation of Structure of VPN Performance Monitoring Data to ALTO
    data format

   The following table lists the ALTO data objects with corresponding
   objects in the VPN performance monitoring YANG data model [I-D.ietf-
   opsawg-yang-vpn-service-pm].  Note that the network topology data
   described in VPN performance monitoring model represents aggregated
   topology information,i.e., overlay network topology information.When
   VPN performance data gets changed, the translation function defined
   in this document should be triggered to fetch the updated network
   topology data and translate them into ALTO map data.  This can be
   realized by using I2RS Pub/Sub Retrieval.

   +----------------------------------+--------------------------------+
   | YANG data node in                | ALTO data object               |
   | /nw:networks/nw:network/nw:link  |                                |
   +----------------------------------+--------------------------------+
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:loss-statistics              |      /PIDName/DstCost          |
   |/nvp:packet-loss-count            |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:loss-statistics              |      /PIDName/DstCost          |
   |/nvp:packet-reorder-count         |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:loss-statistics              |      /PIDName/DstCost          |
   |/nvp:packet-out-of-seq-count      |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:loss-statistics              |      /PIDName/DstCost          |
   |/nvp:packet-dup-count             |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:loss-statistics              |      /PIDName/DstCost          |

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   |/nvp:loss-ratio                   |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:direction                    |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:unit-value                   |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:min-delay-value              |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:max-delay-value              |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:low-delay-percentile         |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:middle-delay-percentile      |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:delay-statistics             |      /PIDName/DstCost          |
   |/nvp:high-delay-percentile        |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:jitter-statistics            |      /PIDName/DstCost          |
   |/nvp:unit-value                   |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:jitter-statistics            |      /PIDName/DstCost          |
   |/nvp:min-jitter-value             |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:jitter-statistics            |      /PIDName/DstCost          |
   |/nvp:max-jitter-value             |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:jitter-statistics            |      /PIDName/DstCost          |
   |/nvp:low-jitter-percentile        |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:jitter-statistics            |      /PIDName/DstCost          |

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   |/nvp:middle-jitter-percentile     |                                |
   |                                  |                                |
   |/nvp:link-telemetry/attributes    | network-map/PIDName            |
   |/nvp:jitter-statistics            |      /PIDName/DstCost          |
   |/nvp:high-jitter-percentile       |                                |
   +----------------------------------+--------------------------------+

8.  Proposed ALTO protocol extension

   ALTO is designed on two abstractions that are useful here.  First is
   the abstraction of the physical network topology into an aggregated
   but logical topology.  The second abstraction that is useful for LMAP
   (Large Scale Measurement of Broadband Performance) [RFC7594] is the
   notion of a "cost map".

   To support network topology data exposure using ALTO protocol, two
   ALTO protocol extensions are required:

   o  Additional address types such as MAC address, VLAN ID need to be
      defined to represent layer 2 endpoint address.

   o  Additional entity property type such as termination points needs
      to be introduced to express how two endpoints or network element
      are connected to each other.

   In addition, path vector needs to be investigated to see how a set of
   service flows are steered in the different network path.

9.  Security Considerations

   TBD

10.  Acknowledgements

   TBD

11.  IANA Considerations

   TBD

12.  References

12.1.  Informative References

   [Grieves2014]
              Grieves, M., "Digital twin: Manufacturing excellence
              through virtual factory replication", 2003.

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12.2.  Normative References

   [I-D.ietf-opsawg-yang-vpn-service-pm]
              Wu, B., Wu, Q., Boucadair, M., Dios, O. G. D., Wen, B.,
              Liu, C., and H. Xu, "A YANG Model for Network and VPN
              Service Performance Monitoring", draft-ietf-opsawg-yang-
              vpn-service-pm-00 (work in progress), February 2021.

   [I-D.zhou-nmrg-digitaltwin-network-concepts]
              Zhou, C., Yang, H., Duan, X., Lopez, D., Pastor, A., Wu,
              Q., Boucadair, M., and C. Jacquenet, "Concepts of Digital
              Twin Network", draft-zhou-nmrg-digitaltwin-network-
              concepts-03 (work in progress), February 2021.

   [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>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC7594]  Eardley, P., Morton, A., Bagnulo, M., Burbridge, T.,
              Aitken, P., and A. Akhter, "A Framework for Large-Scale
              Measurement of Broadband Performance (LMAP)", RFC 7594,
              DOI 10.17487/RFC7594, September 2015,
              <https://www.rfc-editor.org/info/rfc7594>.

   [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>.

   [RFC8345]  Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A YANG Data Model for
              Network Topologies", RFC 8345, DOI 10.17487/RFC8345, March
              2018, <https://www.rfc-editor.org/info/rfc8345>.

   [RFC8542]  Zhuang, Y., Shi, D., Gu, R., and H. Ananthakrishnan, "A
              YANG Data Model for Fabric Topology in Data-Center
              Networks", RFC 8542, DOI 10.17487/RFC8542, March 2019,
              <https://www.rfc-editor.org/info/rfc8542>.

   [RFC8944]  Dong, J., Wei, X., Wu, Q., Boucadair, M., and A. Liu, "A
              YANG Data Model for Layer 2 Network Topologies", RFC 8944,
              DOI 10.17487/RFC8944, November 2020,
              <https://www.rfc-editor.org/info/rfc8944>.

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Internet-Draft         ALTO for Network Topo Data              June 2021

Authors' Addresses

   Hanshu Hong
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: honghanshu@huawei.com

   Cheng Zhou
   China Mobile
   Beijing  100053
   China

   Email: zhouchengyjy@chinamobile.com

   Chongfeng Xie
   China Telecom
   Beijing
   China

   Email: xiechf@chinatelecom.cn

   Qiufang Ma
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: maqiufang1@huawei.com

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