[Docs] [txt|pdf] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02

CCAMP Working Group                                             N. Sambo
Internet-Draft                                               P. Castoldi
Intended status: Standards Track                          A. Sgambelluri
Expires: April 25, 2019                       Scuola Superiore Sant'Anna
                                                             G. Fioccola
                                                     Huawei Technologies
                                                               F. Cugini
                                                                    CNIT
                                                           D. Ceccarelli
                                                                Ericsson
                                                                 H. Song
                                                                 T. Zhou
                                                                  Huawei
                                                        October 22, 2018


      Finite state machine YANG model augmentation for Transponder
                            Reconfiguration
            draft-sambo-ccamp-yang-fsm-transponder-reconf-02

Abstract

   YANG enables to compile a set of consistent vendor-neutral data
   models for optical networks and components based on actual
   operational needs emerging from heterogeneous use cases.  A YANG
   model has been also proposed to describe finite state machine to
   program network elements that are modeled with YANG.  This document
   augments the more generic YANG model for finite state machine
   [I-D.sambo-netmod-yang-fsm], in order to pre-instruct an optical
   transponder on the actions to be performed (e.g., code adaptation) in
   case some events, such as physical layer degradations, occur.

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
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on April 25, 2019.



Sambo, et al.            Expires April 25, 2019                 [Page 1]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


Copyright Notice

   Copyright (c) 2018 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
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   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.  Conventions used in this document . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Flexible Transponders . . . . . . . . . . . . . . . . . . . .   4
   5.  Augmenting the FSM YANG model for transponder reconfiguration   7
   6.  Code of the YANG model for transponder reconfiguration  . . .  10
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  16
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  16
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  16
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  16
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  16
     10.2.  Informative References . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   Networks are evolving toward more programmability, flexibility, and
   multi-vendor interoperability.  Multi-vendor interoperability can be
   applied in the context of nodes, i.e. a node composed of components
   provided by different vendors (named fully disaggregated white box)
   is assembled under the same control system.  This way, operators can
   optimize costs and network performance without the need of being tied
   to single vendor equipment.  NETCONF protocol RFC6241 [RFC6241] based
   on YANG data modeling language RFC6020 [RFC6020] is emerging as a
   candidate Software Defined Networking (SDN) enabled protocol.  First,
   NETCONF supports both control and management functionalities, thus
   permits high programmability.  Then, YANG enables data modeling in a
   vendor-neutral way.  Some recent works have provided YANG models to
   describe attributes of links (e.g., identification), nodes (e.g.,
   connectivity matrix), media channels, and transponders (e.g.,
   supported forward error correction - FEC) of networks



Sambo, et al.            Expires April 25, 2019                 [Page 2]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   ([I-D.ietf-i2rs-yang-network-topo] [I-D.vergara-ccamp-flexigrid-yang]
   [I-D.zhang-ccamp-l1-topo-yang]), also including optical technologies.
   A YANG model [I-D.sambo-netmod-yang-fsm] has been also proposed to
   describe finite state machines (FSMs) in order to program actions
   based on conditions and events in YANG-described devices.  Such draft
   mainly refers to elastic optical networks (EONs), i.e. optical
   networks based on flexible grid where circuits with different
   bandwidth requirements are switched.  EONs are expected to employ
   flexible transponders, i.e. transponders supporting multiple bit
   rates, multiple modulation formats, and multiple codes.  Such
   transponders permits the (re-) configuration of the bit rate value
   based on traffic requirements, as well as the configuration of the
   modulation format and code based on the physical characteristics of a
   path (e.g., quadrature phase shift keying is more robust than 16
   quadrature amplitude modulation).  This document augments the YANG
   model for FSM [I-D.sambo-netmod-yang-fsm] to be applied in
   programming reconfiguration of transponders in EONs based on physical
   layer conditions.  In particular, the model enables a centralized
   remote network controller (managed by a network operator) to instruct
   a transponder controller about the actions to perform when certain
   events (e.g., failures) occur.  The actions to be taken and the
   events can be re-programmed on the device.

2.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC2119 [RFC2119].

3.  Terminology

   ABNO: Application-Based Network Operations

   BER: Bit Error Rate

   EON: Elastic Optical Network

   FEC: Forward Error Correction

   FSM: Finite State Machine

   NETCONF: Network Configuration Protocol

   OAM: Operation Administration and Maintenance

   SDN: Software Defined Network

   YANG: Yet Another Network Generator



Sambo, et al.            Expires April 25, 2019                 [Page 3]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


4.  Flexible Transponders

   Flexible transponders enable several parameters' configurations,
   through the support of multiple modulation formats, baud rate, and
   forward error correction (FEC) schemes.  This way, transmission
   parameters can be (re-)configured based on the physical layer
   conditions.  The YANG model presented in this draft enables to pre-
   program reconfiguration settings of data plane devices in case of
   changes in the physical layer conditions.  In particular, soft
   failures can be assumed.  Soft failures imply transmission
   performance degradation, in turns a bit error rate (BER) increase,
   e.g. due to the ageing of some network devices.  Without loosing
   generality, the ABNO architecture is assumed for the control and
   management of EONs (RFC7491 [RFC7491]).  Considering the state of the
   art, when pre-FEC BER passes above a predefined threshold, it is
   expected that an alarm is sent to the OAM Handler, which communicates
   with the ABNO controller that may trigger an SDN controller (that
   could be the Provisioning Manager of ABNO RFC7491 [RFC7491]) for
   computing new transmission parameters.  The involved ABNO modules are
   shown in the simplified ABNO architecture of Fig. 1.  Then,
   transponders are reconfigured.  When alarms related to several
   connections impacted by the soft failure are generated, this
   procedure may be particularly time consuming.  The related workflow
   for transponder reconfiguration is shown in Fig. 2.  The proposed
   model enables an SDN controller to instruct the transponder about
   reconfiguration of new transmission parameters values if a soft
   failure occurs.  This can be done before the failure occurs (e.g.,
   during the connection instantiation phase or during the connection
   service), so that data plane devices can promptly reconfigure
   themselves without querying the SDN controller to trigger an on-
   demand recovery.  This is expected to speed up the recovery process
   from soft failures.  The related flow chart is shown in Fig. 3.



















Sambo, et al.            Expires April 25, 2019                 [Page 4]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


          ___________            ___________
         |  ABNO     |          |   OAM     |
         |controller |  ------  |  Handler  |
         |___________|          |___________|

           |                         |
           |                         |
           |                         |
        ____________                 |
       |    SDN     |                |
       | controller |                |
       |____________|                |
                                     |
            |                        |
            |                        |
            |                        |
          _____________________________
         |            Client           |
         |            network          |
         |_____________________________|


                 Figure 1: Assumed ABNO functional modules




























Sambo, et al.            Expires April 25, 2019                 [Page 5]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


              _____________________
             |         1           |
             |Sending alarm to the |
             |        OAM Handler  |
             |                     |
             |_____________________|
                       |
                       |
                       |
             _____________________
            |          2          |
            |       Trigger       |
            |  SDN Controller     |
            |                     |
            |_____________________|
                       |
                       |
                       |
             _____________________
            |          3          |
            |   Computation of    |
            |  new transmission   |
            |    parameters       |
            |_____________________|
                      |
                      |
                      |
             _____________________
            |         4           |
            |    Data plane       |
            |    reconfiguration  |
            |                     |
            |_____________________|


      Figure 2: Flow chart of the expected state-of-the-art approach















Sambo, et al.            Expires April 25, 2019                 [Page 6]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


             _______________________
            |          1            |
            | Instructing the local |
            |   controller of       |
            |  data plane devices   |
            |_______________________|
                       |
                       |
                       |
             _______________________
            |          2            |
            | Local reconfiguration |
            |     upon failure      |
            |       detection       |
            |_______________________|
                       |
                       |
                       |
             _______________________
            |          3            |
            |                       |
            |     notification      |
            |                       |
            |_______________________|


    Figure 3: Flow chart of the approach exploiting YANG models in this
                                   draft

5.  Augmenting the FSM YANG model for transponder reconfiguration

   This section augments the FSM YANG model presented in
   [I-D.sambo-netmod-yang-fsm] to address the specific use case of
   transponder reconfiguration triggered by physical layer changes.  The
   FSM is installed by the SDN controller in the local controller of the
   transponder and then runs there.  The installation of the FSM can be
   enabled through a NETCONF <edit-config> message.  Through FSM, the
   SDN controller instructs the transponder about the possible events
   (e.g., BER above a threshold) and reactions (e.g., change of
   modulation format) by setting the thresholds (e.g., BER threshold)
   and the reconfiguration settings.  The FSM model is based on the
   following main attributes: states, transitions (corresponding to some
   specific event), and actions.  In particular, more specifically with
   respect to [I-D.sambo-netmod-yang-fsm], in such a use case, a state
   corresponds to a specific configuration of transponder transmission
   parameters: e.g., given by the modulation format and the FEC.  A
   transition is triggered when the pre-FEC BER (or another parameter
   such as the OSNR) is below or above a threshold.  To this purpose,



Sambo, et al.            Expires April 25, 2019                 [Page 7]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   with respect to [I-D.sambo-netmod-yang-fsm], the attribute <filter>
   is expressed by the definition of thresholds and operators.  The
   action mainly consists of the change of modulation format and/or FEC.

   The Tree of the YANG model for transponder reconfiguration
   (augmentation of the YANG model for FSM) is reported below.

   module: ietf-treconf
      +--rw current-state?   leafref
      +--rw states
         +--rw state [id]
            +--rw id             state-id-type
            +--rw description?   string
            +--rw transitions
               +--rw transition [name]
                  +--rw name                   string
                  +--rw description?           string
                  +--rw threshold-parameter?   decimal64
                  +--rw threshold-operator?    string
                  +--rw transition-action
                     +--rw action [id]
                        +--rw id        transition-id-type
                        +--rw type      enumeration
                        +--rw simple
                           +--rw execute
                           +--rw next-action?   transition-id-type
                           +--rw next-state?    Leafref


   More specifically, the attribute <state> is a list defining all the
   transponder states. <transitions> is an attribute defining a list of
   events that may trigger the change of transponder state (e.g., BER
   change). <threshold-parameter> defines a threshold value, while
   <threshold-operator> defines the operator <,>,<=,>=.  Thus, if the
   event BER>TH has to be modeled, the attribute <threshold-parameter>
   has to be set to "TH" while <threshold-operator> to ">".  <actions>
   defines a list of actions to take during the transition (e.g. change
   of modulation format) <next-state> defines the next transponder state
   when an action is executed (e.g., new modulation format and FEC).

   For more details about the other model attributes, the reader can
   refer to [I-D.sambo-netmod-yang-fsm].

   In such a use case, we assume that an event (e.g., BER>TH) is
   revealed by the digital signal processing (DSP) of the receiver.
   Once the event is recognized, the modulation format and/or the FEC
   have to be changed, both at the receiver and the transmitter.  Thus,
   the list of actions to be executed includes the change of



Sambo, et al.            Expires April 25, 2019                 [Page 8]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   transmission parameters at the receiver side.  Moreover, transmission
   and receiver must be synchronized about the transmission settings
   (modulation format and so no) for a proper transmission.  Thus, when
   the transponder at the receiver side decides to change its state, the
   remote transponder at the transmitter side has to do the same state
   transition.  To this purpose, the list of actions also includes this
   coordination.  In particular, the transponder at the receiver side
   sends a message to the transmitter to synchronize about the
   transmission parameters to be adopted.  This message can be sent over
   a control channel.  This way both the transmitter and receiver
   operates with the same transmission parameters: e.g.  the format,
   FEC, and so on.

   Such transponder reconfiguration based on FSM has been successfully
   demonstrated by integrating control and data planes in a lab and
   field trials.

   Finally, a last consideration concerns the impact on transmission bit
   rate when changing some transmission parameters.  When passing from a
   more spectral efficient modulation format (but less robust with
   respect to physical impairments) to a less spectral efficient
   modulation format (more robust) such that could be polarization
   multiplexing 16 quadrature phase shift keying (PM-16QAM) and PM
   quadrature phase shift keying (PM-QPSK) the bit rate is reduced
   (halved in the case of PM-16QAM and PM-QPSK).  This means that part
   of the traffic cannot be recovered through FSM, but needs of other
   restoration mechanisms (e.g., dynamic restoration).  As an example,
   the gain of the proposed FSM mechanism promptly recovering part of
   the bit rate can be applied to high-priority traffic so that its
   recovery can be faster without involving central controller, while
   other classical recovery mechanisms (involving the sending of alarms,
   their processing, new computations and setup) can be adopted for best
   effort traffic (as the traffic that cannot be recovered when passing
   from PM-16QAM to PM-QPSK).  The same happens changing the code rate:
   at fixed baud rate and modulation format, if the code redundancy is
   increased, the net bit rate is decreased.  Again, part of the traffic
   can be promptly recovered through FSM, while the other by relying on
   classical recovery mechanisms.  Another case of applicability is
   related to the "functional split" in next generation radio access
   networks (RANs).  In this scenario, the evolved NodeB (eNB) functions
   are split into two new, most likely virtualized, network entities:
   the Central Unit (CU) deployed in centralized locations and the
   Distributed Unit (DU) deployed near the antenna.  Several functional
   splits are being considered, e.g. by 3GPP in TR 38.801 and IEEE 1914
   Working Group in Next Generation Fronthaul Interface (NGFI).  They
   demand different requirements in terms of latency and capacity to the
   fronthaul network connecting DU and CU.  For example, in 3GPP TR
   38.801, according to "Option 7c" functional split, 10.1-22.2Gb/s and



Sambo, et al.            Expires April 25, 2019                 [Page 9]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   53.8-86.1Gb/s are required in the downstream and upstream links,
   respectively, while, according to "Option 8" functional split,
   157.3Gb/s is required both in downstream and upstream links.  Thus,
   the change of rate could reflect into a change of functional split.

6.  Code of the YANG model for transponder reconfiguration

   The related code is reported below.

<CODE BEGINS> file "ietf-treconf@2016-03-15.yang"


 module ietf-treconf {
  namespace "http://sssup.it/fsm";
  prefix fsm;


  organization
    "Scuola Superiore Sant'Anna Network and Services Laboratory";

  contact
    " Editor: Matteo Dallaglio
              <mailto:m.dallaglio@sssup.it>
    ";

  description
    "This module contains a YANG definitions of a generic finite state
        machine.";

  revision 2016-03-15 {
    description "Initial Revision.";
    reference
      "RFC xxxx:";
  }


  identity TRANSITION {
      description "Base for all types of event";
  }

  identity ON_CHANGE {
      base TRANSITION;
      description
        "The event when the database changes.";
  }


  // typedef statements



Sambo, et al.            Expires April 25, 2019                [Page 10]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


  typedef transition-type {
        description "it defines the transition type";
    type identityref {
      base TRANSITION;
    }
  }

  typedef transition-id-type {
        description "it defines the transition id type";
    type uint32;
  }


  // grouping statements
  grouping action-block {
        description "it defines the grouping action";
    leaf id {
        description "it defines the id of the transition";
      type transition-id-type;
    }
    leaf type {
    description "it defines if the action has to be simply executed
    or if a conditional statement has to be checked before execution";

      type enumeration {
        enum "CONDITIONAL_OP"{
description "it defines the type CONDITIONAL OPERATION to check a
statement before execution. In this draft, at the moment, only SIMPLE
will be assumed";

 }
        enum "SIMPLE_OP"{
description "it defines the type SIMPLE OPERATION: i.e., an operation
to be directly executed;
}
      }
      mandatory true;
    }

    grouping execution-top {
        description "it defines the execution attribute";
      anyxml execute {
        description "Represent the action to perform";
      }
      leaf next-action {
        type transition-id-type;
        description "the id of the next action to execute";
      }



Sambo, et al.            Expires April 25, 2019                [Page 11]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


    }


    container simple {
      when "../type = 'SIMPLE_OP'";
      description
        "Simple execution of an action without checking any condition";
      uses execution-top;
    }
  }

  grouping action-top {
        description "it defines the grouping of action";
    list action {
                description "it defines the list of actions";
      key "id";

      ordered-by user;
      uses action-block;
    }
  }

  grouping on-change {
    description
      "Event occuring when a modification of one or more
       objects occurs";

    leaf threshold-parameter {
    description "it defines the threshold of an event determined by
    a threshold exceed";
      type decimal64;
    }

    leaf threshold-operator {
    description "it defines the operator to check the threshold
    exceed: <, > <=, >=";
      type string;
    }


  }

  grouping transition-top {
        description "it defines the grouping transition";
    leaf name {
        description "it defines the transition name";
      type string;
      mandatory true;



Sambo, et al.            Expires April 25, 2019                [Page 12]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


    }



    leaf description {
description "it describes the transition with a string";
      type string;
    }

    // list of all possible events
    uses on-change {
      when "type = 'ON_CHANGE'";
    }

    container transition-action {
        description "it defines the container actions to take during the
        transition";
      uses action-top;
    }
  }

  grouping transitions-top {
        description "it defines the grouping transition";
    container transitions {
        description "it defines the container transitions";
      list transition {
                description "it defines the list of transitions";
        key "name";
        uses transition-top;

      }
    }
  }


  // data definition statements

  uses transitions-top;

  // extension statements

  // feature statements

  // augment statements

  // rpc statements

  // notification statements



Sambo, et al.            Expires April 25, 2019                [Page 13]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


  // identity statements

  // typedef statements

  typedef state-id-type {
        description "it defines the id type of the states";
    type uint32;
  }


  // grouping statements
  grouping state-top {
        description "it defines the grouping state";
    leaf id {
        description "it defines the id of the state";
      type state-id-type;
    }

    leaf description {
        description "it describes the state with a string";
      type string;
    }


    grouping next-state-top {
        description "it defines the grouping next state";
      leaf next-state {
          type leafref {
            path "../../../../../../../../../states/state/id";
          }
          description "Id of the next state";
        }
    }

    uses transitions-top {
      augment "transitions/transition/transition-action/action/simple" {
        //uses next-state-top;
        leaf next-state {
          type leafref {
            path "../../../../../../../../states/state/id";
          }
          description "Id of the next state";
        }
      }
    }

  }




Sambo, et al.            Expires April 25, 2019                [Page 14]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


  grouping states-top {
        description "it defines the attributes of state-top";
    leaf current-state {
        description "it defines the current state";
      type leafref {
                description "it refers to its id";
        path "../states/state/id";
      }
    }

    container states {
        description "it defines the container states";
      list state {
        description "it defines the list of states";
        key "id";
        uses state-top;
      }
    }
  }


  // data definition statements



  uses states-top;

  // extension statements


  // feature statements

  // augment statements.

  // rpc statements

  // notification statements


}//module fsm



<CODE ENDS>







Sambo, et al.            Expires April 25, 2019                [Page 15]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


7.  Acknowledgements

   This work has been partially supported by the European Commission
   through the EU H2020 5G-TRANSFORMER Project (grant no. 761536) and
   the H2020 ORCHESTRA (Optical peRformanCe monitoring enabling dynamic
   networks using a Holistic cross-layEr, Self-configurable Truly
   flexible approach, grant agreement no: H2020-645360) project.  The
   views expressed here are those of the authors only.  The European
   Commission is not liable for any use that may be made of the
   information in this document.

8.  Security Considerations

   TBD

9.  IANA Considerations

   TBD

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>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [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>.

   [RFC7491]  King, D. and A. Farrel, "A PCE-Based Architecture for
              Application-Based Network Operations", RFC 7491,
              DOI 10.17487/RFC7491, March 2015,
              <https://www.rfc-editor.org/info/rfc7491>.

10.2.  Informative References







Sambo, et al.            Expires April 25, 2019                [Page 16]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   [I-D.ietf-i2rs-yang-network-topo]
              Clemm, A., Medved, J., Varga, R., Bahadur, N.,
              Ananthakrishnan, H., and X. Liu, "A Data Model for Network
              Topologies", draft-ietf-i2rs-yang-network-topo-20 (work in
              progress), December 2017.

   [I-D.sambo-netmod-yang-fsm]
              Sambo, N., Castoldi, P., Fioccola, G., Cugini, F., Song,
              H., and T. Zhou, "YANG model for finite state machine",
              draft-sambo-netmod-yang-fsm-03 (work in progress), July
              2018.

   [I-D.vergara-ccamp-flexigrid-yang]
              Madrid, U., Perdices, D., Lopezalvarez, V., Dios, O.,
              King, D., Lee, Y., and G. Galimberti, "YANG data model for
              Flexi-Grid Optical Networks", draft-vergara-ccamp-
              flexigrid-yang-06 (work in progress), January 2018.

   [I-D.zhang-ccamp-l1-topo-yang]
              zhenghaomian@huawei.com, z., Fan, Z., Sharma, A., and X.
              Liu, "A YANG Data Model for Optical Transport Network
              Topology", draft-zhang-ccamp-l1-topo-yang-07 (work in
              progress), April 2017.

Authors' Addresses

   Nicola Sambo
   Scuola Superiore Sant'Anna
   Via Moruzzi 1
   Pisa  56124
   Italy

   Email: nicola.sambo@sssup.it


   Piero Castoldi
   Scuola Superiore Sant'Anna
   Via Moruzzi 1
   Pisa  56124
   Italy

   Email: piero.castoldi@sssup.it









Sambo, et al.            Expires April 25, 2019                [Page 17]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   Andrea Sgambelluri
   Scuola Superiore Sant'Anna
   Via Moruzzi 1
   Pisa  56124
   Italy

   Email: andrea.sgambelluri@sssup.it


   Giuseppe Fioccola
   Huawei Technologies
   Riesstrasse, 25
   Munich  80992
   Germany

   Email: giuseppe.fioccola@huawei.com


   Filippo Cugini
   CNIT
   Via Moruzzi 1
   Pisa  56124
   Italy

   Email: filippo.cugini@cnit.it


   Daniele Ceccarelli
   Ericsson
   Torshamnsgatan,48
   Stockholm  164 40
   Sweden

   Email: daniele.ceccarelli@ericsson.com


   Haoyu Song
   Huawei
   2330 Central Expressway
   Santa Clara, CA  95050
   USA

   Email: haoyu.song@huawei.com








Sambo, et al.            Expires April 25, 2019                [Page 18]


Internet-Draft       FSM YANG for Transponder Reconf        October 2018


   Tianran Zhou
   Huawei
   156 Beiqing Road
   Beijing  100095
   China

   Email: zhoutianran@huawei.com












































Sambo, et al.            Expires April 25, 2019                [Page 19]


Html markup produced by rfcmarkup 1.129b, available from https://tools.ietf.org/tools/rfcmarkup/