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Versions: 00                                                            
Network Working Group                                              X. Fu
Internet-Draft                                                  M. Betts
Intended status: Standards Track                         ZTE Corporation
Expires: October 28, 2010                                        R. Jing
                                                                  X. Huo
                                                           China Telecom
                                                          April 26, 2010


 OSPF-TE Extension for Multi Stages Multiplexing Configuration in G.709
                       Optical Transport Network
         draft-fuxh-ccamp-multi-stage-multiplex-config-ospf-00

Abstract

   Multi stages multiplexing configuration requirement is defined in
   [MULTI-STAGES-MULTIPLEXING-CONFIG-REQ] document.  Multi stages
   multiplexing configuration framework is diefined in [MULTI-STAGES-
   MULTIPLEXING-CONFIG-FRW] document.  They describe some scenarios for
   the interworking between regions with 1.25G TS and 2.5G TS and the
   multi-domain OTN applications based on the tunnel design.  Multi
   stages multiplexing is desirable to facilitate the introduction of
   new ODU0 and ODUflex signals to an existing network without having to
   upgrade every node in the network.  So ODU0/ODUflex can be mapped
   into ODU1/ODU2/ODU3 and transit across the 2.5G TS region.  Multi
   stages multiplexing/demultiplexing are also used to support the
   multi-domain OTN applications based on the tunnel design.  From the
   perspective of Management Plane and Control Plane, they must get
   multi stages multiplexing/demultiplexing capability of each gateway
   nodes for path computation.  This document describes the OSPF-TE
   extension for multi stages multiplexing configuration in G.709
   Optical Transport Network.

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 RFC 2119 [RFC2119].

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 http://datatracker.ietf.org/drafts/current/.



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   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire on October 28, 2010.

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  OSPF-TE Extension for Multi Stages Multiplexing
       Configuration  . . . . . . . . . . . . . . . . . . . . . . . .  4
     2.1.  Multi Stages Multiplexing Capability Constraint Sub-TLV  .  5
     2.2.  Multi Stages Multiplexing Capability OSPF-TE Extension
           Example  . . . . . . . . . . . . . . . . . . . . . . . . .  6
     2.3.  Routing Procedure  . . . . . . . . . . . . . . . . . . . . 10
   3.  Security Considerations  . . . . . . . . . . . . . . . . . . . 10
   4.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11
   5.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
     5.1.  Normative References . . . . . . . . . . . . . . . . . . . 11
     5.2.  Informative References . . . . . . . . . . . . . . . . . . 11
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11




































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1.  Introduction

   G.709 has supported a single stage of ODU multiplexing.  The
   practical consequence of this in OTN v1 is an ODU1 can be mapped
   directly to a tributary slot of an ODU3, without having to be first
   mapped into an ODU2.  The motivation for this architecture is
   reducing complexity.  In the normal progression of things, new
   additions to the OTN were expected to be at faster bit rates, and
   thus the single stage concept could be easily maintained going
   forward.

   The introduction of ODU0 and ODUflex to the OTN hierarchy creates a
   situation where the newly added ODUk signals have a bit rate that is
   lower than any of the existing signals, which presents some different
   challenges because the new signals can be clients of the existing
   signals.  As a result, there are clear applications where multi
   stages of multiplexing would be desirable to facilitate the
   introduction of these new ODU0 and ODUflex signals to an existing
   network without having to upgrade every node in the network.  Using
   multi stages of multiplexing allows the operator to confine the new
   rates to only those nodes that need to support them.

   A second potential application for multi stages outside of an upgrade
   scenario would be a network design based on tunnels.  Multi stages
   multiplexing are used to support the multi-domain OTN applications
   based on the tunnel design.

   From the perspective of Control Plane, path computation entity must
   get multi stages multiplexing/demultiplexing capability of each
   gateway nodes for path computation.  This document describes the
   OSPF-TE extension in order for multi stages multiplexing
   configuration in G.709 Optical Transport Network.


2.  OSPF-TE Extension for Multi Stages Multiplexing Configuration

   Multi stages multiplexing/demultiplexing capability information must
   be flooded into the path computation entity and the routing domain by
   gateway nodes with the IGP protocol.  LSAs which are advertised by
   gateway nodes must carry multi stages multiplexing/demultiplexing
   capability information.  Multi stages multiplexing/demultiplexing
   capability should be configured by Management Plane (e.g., Network
   Planning Tool) or discovered by the gateway node based on the
   switching and adaptation capability of switching fabrics and cards.

   This document defines extensions to the OSPF routing protocol which
   is defined in [RFC3630], [RFC4202], and [RFC4203] in order for multi
   stages multiplexing configuration.  The TE LSA, which is an opaque



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   LSA with area flooding scope [RFC3630], has only one top-level Type/
   Length/Value (TLV) triplet and has one or more nested sub-TLVs.  One
   of the top-level TLVs is Link [RFC3630] value.  This document
   enhances the sub-TLVs for the Link TLV to support Multi Stages
   Multiplexing Configuration.

2.1.  Multi Stages Multiplexing Capability Constraint Sub-TLV

   The Link top-level TLV is defined in [RFC3630], [RFC4203].  Link ID,
   Administrative Group, Interface Switching Capability
   Descriptor(ISCD), Link Protection Type, Shared Risk Link Group
   Information (SRLG), and Traffic Engineering Metric are among the
   typical link sub-TLVs.  In order to make path computation entity get
   the multi stages multiplexing capability information of gateway node,
   this document add an additional sub-TLV to the Link-TLV.  If there is
   no any multi stages multiplexing configuration for operator, This
   sub-TLV is optional for OTN application.  Single stage multiplexing
   capability don't need to be indicated by this sub-TLV.

   Multi Stages Multiplexing Capability Constraint is a sub-TLV of the
   Link TLV.  The type of this sub-TLV will be assigned by IANA, and
   length is eight octets.  The value field of this sub-TLV contains
   multi stages multiplexing capability information which is supported
   by link port.


      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |      Type (TBD) (IANA)        |          Length               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Number    |     Reserve   |MSMH 1 |     ...MSMC 1...      |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |MSMH 1 |     ...MSMC 2...      |            ...                |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |MSMH M |        ...MSMC M...       |           padding         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   o  Number (8 bits): Indicates the total nunmber of multi stages
      multiplexing capability which is supported by the link port.

   o  Reserve (8 bits): for future use.

   o  (MSMH 1, MSMC 1), (MSMH 2, MSMC 2), ... ,(MSMH M, MSMC M):
      Indicates each multi stages multiplexing capability detailed
      information.





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      *  MSMH 1, MSMH2, ... , MSMH M (4 bits): Indicates the Multi
         Stages Multiplexing Hierarchies (MSMH).

      *  MSMC 1, MSMC 2, ... ,MSMC M: Indicates the multi stages
         multiplexing capability.  The length of Multi Stages
         Multiplexing Capability (MSMC) information depends on the multi
         stages multiplexing hierarchies (MSMH).  The length of MSMC is
         (MSMH+1) * 4.  Each ODUk (k=1, 2, 3, 4, 2e, flex) is indicated
         by 4 bits.  Following is the Signal Type for G.709 Amendment 3.


                           Value  Type
                            -----  ----
                           0000    ODU0
                           0001    ODU1
                           0010    ODU2
                           0011    ODU3
                           0100    ODU4
                           0101    ODU2e
                           0110    ODUflex
                           7-15    Reserved (for future use)

   o  The padding is used to make the Multi Stages Multiplexing
      Capability sub-TLV 32-bits aligned.

2.2.  Multi Stages Multiplexing Capability OSPF-TE Extension Example

   In the following figure, different gateway nodes support different
   multi stages multiplexing/demultiplexing capability.  From the
   perspective of Control Plane, it must get multi stages multiplexing/
   demultiplexing capability of each gateway nodes for path computation.
   So the path computation entity can select a proper kind of multi
   stages multiplexing/demultiplexing of gateway nodes along a specific
   E2E connection.

   Gateway 2 provides demultiplexing to recover the ODU2 from ODU4 and
   an additional multiplexing of the ODU2 to ODU3 and vice versa.














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                                     --
                                   /|12|\
                                  /  --  \
                                 /        \
                             -- /   ODU2   \--
                            |11| Network 4 |13|
                             -- \         / --
                                 \       /
                                  \  -  /
                                   \| |/
                                     - Gateway4
                                     |
                                     |
                -                    -                     -
              /|2|\                /|5|\                 /|8|\
             /  -  \              /  -  \               /  -  \
            /       \            /       \             /       \
         - /   ODU2  \ -      - /   ODU3  \ -       - /   ODU2  \ --
        |1| Network 1 | |----|4| Network 2 |7|---- | | Network 3 |10|
         - \         / -      - \         / -       - \         / --
            \       /Gateway1    \       /     Gateway3\       /
             \  -  /              \  -  /               \  -  /
              \|3|/                \|6|/                 \|9|/
                -                    -                     -
                                     |
                                     -
                                    | |Gateway2
                                     -
                                     |
             --                      --                     --
           /|15|\                  /|18|\                 /|21|\
          /  --  \                /  --  \               /  --  \
         /        \              /        \             /        \
     -- /   ODU2   \ --      -- /   ODU4   \--      -- /   ODU3   \ --
    |14| Network 5  |  |----|17| Network 6 |20|----|  | Network 7  |23|
     -- \          / --      -- \          /--      -- \          / --
         \        /Gateway5      \        /     Gateway7\        /
          \  --  /                \  --  /               \  --  /
           \|16|/                  \|19|/                 \|22|/
             --                      --                     --


   Gateway 1 supports the following multi stages multiplexing/
   demultiplexing capability.

   o  ODU0-ODU1-ODU3





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   o  ODU0-ODU2-ODU3

   o  ODU1-ODU2-ODU3

   o  ODUflex-ODU2-ODU3

   The value of Multi Stages Multiplexing Capability Constraint Sub-TLV
   is as followings:


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type (TBD)              |          Length(12)           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       4       |    Reserve    |0 1 0|0 0 0 0|0 0 0 1|0 0 1 1|0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1 0|0 0 0 0|0 0 1 0|0 0 1 1|0 1 0|0 0 0 1|0 0 1 0|0 0 1 1|0 1 0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |0 1 1 0|0 0 1 0|0 0 1 1|               padding                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Gateway 3 supports the following multi stages multiplexing/
   demultiplexing capability.

   o  ODU0-ODU2-ODU3

   o  ODUflex-ODU2-ODU3

   The value of Multi Stages Multiplexing Capability Constraint Sub-TLV
   is as followings:


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type (TBD)               |          Length(8)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       2       |    Reserve    |0 1 0|0 0 0 0|0 0 1 0|0 0 1 1|0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1 0|0 1 1 0|0 0 1 0|0 0 1 1|               padding             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Gateway 4 supports the following multi stages multiplexing/
   demultiplexing capability.  It doesn't support the ODUflex-ODU2-ODU3
   multiplexing.  The operator limits the ODUflex application to the
   local network.  There is no any multi-domain ODUflex application
   which goes into ODU2 Network 4.



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   o  ODU0-ODU1-ODU3

   o  ODU0-ODU2-ODU3

   The value of Multi Stages Multiplexing Capability Constraint Sub-TLV
   is as followings:


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type (TBD)               |          Length(8)            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       2       |    Reserve    |0 1 0|0 0 0 0|0 0 0 1|0 0 1 1|0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1 0|0 0 0 0|0 0 1 0|0 0 1 1|               padding             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Gateway 5 supports the following multi stages multiplexing/
   demultiplexing capability.

   o  ODU0-ODU2-ODU4

   o  ODU0-ODU3-ODU4

   o  ODU1-ODU2-ODU4

   o  ODU1-ODU3-ODU4

   o  ODUflex-ODU2-ODU4

   o  ODUflex-ODU3-ODU4

   The value of Multi Stages Multiplexing Capability Constraint Sub-TLV
   is as followings:


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type (TBD)               |          Length(16)           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       6       |    Reserve    |0 1 0|0 0 0 0|0 0 1 0|0 1 0 0|0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1 0|0 0 0 0|0 0 1 1|0 1 0 0|0 1 0|0 0 0 1|0 0 1 0|0 1 0 0|0 1 0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |0 0 0 1|0 0 1 1|0 1 0 0|0 1 0|0 1 1 0|0 0 1 0|0 1 0 0|0 1 0|0 1|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



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   |1 0|0 0 1 1|0 1 0 0|              padding                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Gateway 7 supports the following multi stages multiplexing/
   demultiplexing capability.  It doesn't support the ODU1-ODU2-ODU4 and
   ODU1-ODU3-ODU4 multiplexing.  The operator limits the ODU1
   application to the local network.  There is no any multi-domain ODU1
   application which goes into ODU3 Network 7.

   o  ODU0-ODU2-ODU4

   o  ODU0-ODU3-ODU4

   o  ODUflex-ODU2-ODU4

   o  ODUflex-ODU3-ODU4

   The value of Multi Stages Multiplexing Capability Constraint Sub-TLV
   is as followings:


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Type (TBD)               |          Length(12)           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       4       |    Reserve    |0 1 0|0 0 0 0|0 0 1 0|0 1 0 0|0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1 0|0 0 0 0|0 0 1 1|0 1 0 0|0 1 0|0 1 1 0|0 0 1 0|0 1 0 0|0 1 0|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |0 1 1 0|0 0 1 1|0 1 0 0|              padding                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

2.3.  Routing Procedure

   TBD


3.  Security Considerations

   The use of control plane protocols for signaling, routing, and path
   computation opens an OTN to security threats through attacks on those
   protocols.  The data plane technology for an OTN does not introduce
   any specific vulnerabilities, and so the control plane may be secured
   using the mechanisms defined for the protocols discussed.  For
   further details of the specific security measures refer to the
   documents that define the protocols ([RFC3473], [RFC4203], [RFC4205],
   [RFC4204], and [RFC5440]).  [GMPLS-SEC] provides an overview of



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   security vulnerabilities and protection mechanisms for the GMPLS
   control plane.


4.  IANA Considerations

   TBD


5.  References

5.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [I-D.ietf-ccamp-gmpls-g709-framework]
              Zhang, F., Li, D., Li, H., Belotti, S., Han, J., Betts,
              M., Grandi, P., and E. Varma, "Framework for GMPLS and PCE
              Control of G.709 Optical Transport Networks",
              draft-ietf-ccamp-gmpls-g709-framework-00 (work in
              progress), April 2010.

5.2.  Informative References


Authors' Addresses

   Xihua Fu
   ZTE Corporation

   Email: fu.xihua@zte.com.cn


   Malcolm Betts
   ZTE Corporation

   Email: malcolm.betts@zte.com.cn


   Ruiquan Jing
   China Telecom

   Email: jingrq@ctbri.com.cn







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   Xiaoli Huo
   China Telecom

   Email: huoxl@ctbri.com.cn















































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