CCAMP Working Group                                        D. Ceccarelli
Internet-Draft                                               D. Caviglia
Intended status: Standards Track                                Ericsson
Expires: January 10, 2011                                       F. Zhang
                                                                   D. Li
                                                     Huawei Technologies
                                                                   Y. Xu
                                                                    CATR
                                                              S. Belotti
                                                               P. Grandi
                                                          Alcatel-Lucent
                                                            July 9, 2010


  Traffic Engineering Extensions to OSPF for Generalized MPLS (GMPLS)
                 Control of Evolving G.709 OTN Networks
               draft-ceccarelli-ccamp-gmpls-ospf-g709-02

Abstract

   The recent revision of ITU-T Recommendation G.709 [G709-V3] has
   introduced new fixed and flexible ODU containers, enabling optimized
   support for an increasingly abundant service mix.

   This document describes OSPF routing protocol extensions to support
   Generalized MPLS (GMPLS) control of all currently defined ODU
   containers, in support of both sub-lambda and lambda level routing
   granularity.

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/.

   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 January 10, 2011.

Copyright Notice




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   Copyright (c) 2010 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
   (http://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 . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  OSPF Extensions  . . . . . . . . . . . . . . . . . . . . . . .  4
     2.1.  OTN Interface Switching Capability Descriptor  . . . . . .  4
     2.2.  Example using OTN-ISCD . . . . . . . . . . . . . . . . . .  9
   3.  Compatibility Considerations . . . . . . . . . . . . . . . . . 16
   4.  Security Considerations  . . . . . . . . . . . . . . . . . . . 16
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 16
   6.  Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 16
   7.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
     8.1.  Normative References . . . . . . . . . . . . . . . . . . . 17
     8.2.  Informative References . . . . . . . . . . . . . . . . . . 18
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18






















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1.  Introduction

   An Opaque OSPF (Open Shortest Path First) LSA (Link State
   Advertisements) carrying application-specific information can be
   generated and advertised to other nodes following the flooding
   procedures defined in [RFC5250].  Three types of opaque LSA are
   defined, i.e. type 9 - link-local flooding scope, type 10 - area-
   local flooding scope, type 11 - AS flooding scope.

   Traffic Engineering (TE) LSA using type 10 opaque LSA is defined in
   [RFC3630] for TE purposes.  This type of LSA is composed of a
   standard LSA header and a payload including one top-level TLV (Type/
   Length/Value triplet) and possible several nested sub-TLVs.
   [RFC3630] defines two top-level TLVs: Router Address TLV and Link
   TLV; and nine possible sub-TLVs for the Link TLV, used to carry link
   related TE information.

   The Link type sub-TLVs are enhanced by [RFC4203] in order to support
   GMPLS networks and related specific link information.

   In GMPLS networks each node generates TE LSAs to advertise its TE
   information and capabilities (link-specific or node-specific),
   through the network.  The TE information carried in the LSAs are
   collected by the other nodes of the network and stored into their
   local Traffic Engineering Databases (TED).

   In GMPLS enabled G.709 Optical Transport Networks (OTNs), routing
   serves as the foundation for automatically establishing ODUk
   connections through GMPLS RSVP-TE signaling.

   G.709 OTN [G709-V3] includes new fixed and flexible ODU containers,
   two types of Tributary Slots (i.e., 1.25Gbps and 2.5Gbps), and
   supports various multiplexing relationships (e.g., ODUj multiplexed
   into ODUk (j<k)), two different tributary slots for ODUk (K=1, 2, 3)
   and ODUflex signal type, which is being standardized in ITU-T.  In
   order to present this information in the routing process, the OSPF
   protocol needs to be extended.

   For a short overview of OTN evolution and implications of OTN
   requirements on GMPLS routing please refer to [OTN-FWK].  The
   information model and an evaluation against the current solution are
   provided in [OTN-INFO].

   This document describes OSPF LSA extensions to support the G.709v3
   OTNs under the control of GMPLS.

   The routing information for Optical Channel Layer (OCh) (i.e.,
   wavelength) is out of the scope of this document.  Please refer to



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   [WSON-Frame] for further information.


2.  OSPF Extensions

   In terms of GMPLS based OTN networks, each OTUk can be viewed as a
   component link, and each component link can carry one or more types
   of ODUj (j<k).

   Each TE LSA can carry a top-level link TLV with several nested sub-
   TLVs to describe different attributes of a TE link.  Two top-level
   TLVs are defined in [RFC 3630]. (1) The Router Address TLV (referred
   to as the Node TLV) and (2) the TE link TLV.  One or more sub-TLVs
   can be nested into the two top-level TLVs.  The sub-TLV set for the
   two top-level TLVs are also defined in [RFC 3630] and [RFC 4203].

   This document defines a new link sub-TLV, called OTN ISCD sub-TLV
   (Sub-tlv value TBA by IANA, suggested 26).

   One or more component links can be bundled as a TE link.  In case of
   link bundling an OTN-ISCD will be used to describe several component
   links.

   As discussed in [OTN-FWK]and [OTN-INFO], usage of multi-stage
   multiplexing implies the advertisement of cascaded adaptation
   capabilities together with matrix access constraints.  Modifications
   to ISCD/IACD [RFC4202][RFC5339] and [MLN-EXT], if needed, are for
   further study.

2.1.  OTN Interface Switching Capability Descriptor

   The format of the OTN Interface Switching Capability Descriptor is
   defined in Figure 1.


















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       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Switching Cap |   Encoding    |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |0|1|2|3|4|5|6|7|  T  |         |          Reserved             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P0                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P1                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P2                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P3                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P4                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P5                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P6                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P7                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                                                                       |
     ...                            ...                              ...
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P0                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P1                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P2                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P3                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P4                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P5                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P6                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Signal Type  |F|               Bandwidth @ P7                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                         Figure 1: OTN-ISCD format

   Where:



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   o Switching Capability (8 bits): the values for this field are
   defined in [RFC4203] section 1.4.  The only valid value is 100 (TDM).

   o Encoding (8 bits): the values for this field are defined in
   [RFC3471] section 3.1.1 and [RFC4328] section 3.1.1 and the only
   possible ones are:

      o 7 - Digital Wrapper

      o 8 - Lambda (Photonic)

      o 12 - G.709 ODUk (Digital Path)

      o 13 - G.709 Optical Channel

   o Priority flags (8 bits): Indicate the priorities supported on the
   advertised link.  When the flag is set, the corresponding priority is
   supported.  As per IETF definition the highest priority is 0 and the
   lowest is 7.

   o T (3 bits): Indicates the type of the Tributary Slot of the
   advertised TE link.  Possible values are:

      o 0 - 1.25 Gbps

      o 1 - 2.5 Gbps

      o 2-7 for future uses

   o Data Rows: Data rows contain Signal type, Field Qualifier(F) and
   bandwidth at priority Pi.  For the definition of each field refer
   below.

   The number of data rows depends on the number of signal types and
   priority supported.  Rows declared in the LSA MUST contain a
   supported signal type.  Rows declaring bandwidth at priority Pi, MUST
   NOT be declared in case the flag associated to priority Pi is set to
   0.

   Data "rows" are ordered from the highest to the lowest priority.  If
   no priority is supported, just the 0 priority MUST be advertised.

   Please see the Example section for further details.

   o Signal Type (8 bits): Indicates the type of ODU/OTU supported by TE
   link.  Different Signal Types are defined for full lambda and sub-
   lambda capabilities.  Possible values are:




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      o 0 - ODU0 (sub-lambda)

      o 1 - ODU1 (sub-lambda)

      o 2 - ODU2 (sub-lambda)

      o 3 - ODU3 (sub-lambda)

      o 4 - ODU4 (sub-lambda)

      o 5 - ODU2e 8TSs (sub-lambda)

      o 6 - ODU2e 9TSs (sub-lambda)

      o 7 - ODUflex inside ODU1 (sub-lambda)

      o 8 - ODUflex inside ODU2 (sub-lambda)

      o 9 - ODUflex inside ODU3 (sub-lambda)

      o 10 - ODUflex inside ODU4 (sub-lambda)

      o 11 - ODUflex*

      o 12 - ODUflex resizable inside ODU1 (sub-lambda)

      o 13 - ODUflex resizable inside ODU2 (sub-lambda)

      o 14 - ODUflex resizable inside ODU3 (sub-lambda)

      o 15 - ODUflex resizable inside ODU4 (sub-lambda)

      o 16 - ODUflex resizable*

      o 20 - ODU1 (Full Lambda)

      o 21 - ODU2 (Full Lambda)

      o 22 - ODU3 (Full Lambda)

      o 23 - ODU4 (Full Lambda)

      o 24 - ODU2e (Full Lambda)

   * Please note that a distinction between different ODUflex signal
   types is needed, for path computation scopes, when optimizing the
   number of TS used depending on the server layer (i.e.  OTUk).  If
   such distinction is not needed, the value 11 must be used for non



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   resizable ODU-flex and the value 16 must be used for ODU-flex
   resizable.

   Each ODUk in a component link can be advertised only once, either as
   sub-lambda bandwidth or full lambda bandwidth.

   o Unreserved TS at Pi (12 bits): Indicates the number of unreserved
   TSs at priority Pi inside all the component links of the TE link.

   In the GMPLS based OTN networks, the Unreserved Bandwidth of a
   (bundled) TE link is the sum of the unreserved bandwidths of all the
   component links in the (bundled) TE-link.

   o Flag F (1 bits): This flag defines the meaning of the following
   field.  It can assume the following values:

      0 - Unreserved bandwidth at priority Pi expressed in number of TS

      1 - Max LSP bandwidth at priority Pi expressed in number of TS

   The Maximum Bandwidth that an LSP can occupy in a TE link is
   determined by the component link with the maximum unreserved
   bandwidth in such TE link.  For example, if two OTU3 component links
   are bundled in a TE link, the unreserved bandwidth of the first
   component link is 20*1.25G TSs, and the unreserved bandwidth of the
   second component link is 24*1.25G TSs, then the unreserved bandwidth
   of this TE link is 44*1.25G TSs, but the maximum TSs that a LSP can
   occupy in this TE link is 24, not 44.

   In case of non flexible signal type (i.e. non ODUflex) the bit MUST
   be ignored and set to 0.  In case of flexible signal type both
   records MUST be included: Unreserved resources per priority and MAX
   LSP bandwidth per priority.


















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      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P0  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P1  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P2  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P3  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P4  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P5  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P6  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |0|  Unreserved resources per signal type @ P7  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P0     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P1     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P2     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P3     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P4     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P5     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P6     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   7<=ST<=12   |1|        Max LSP Bandwidth (ODUflex) @ P7     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                      Figure 2: OTN-ISCD for ODUFlex

   All the reserved fields MUST be set to zero and SHOULD be ignored
   when received.

2.2.  Example using OTN-ISCD

   The examples in the following pages are not normative and are not
   intended to infer or mandate any specific implementation.  Figure 3
   shows the case of a TE-link composed of two component links.






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                      +------+ component link 1 +------+
                      |      +------------------+      |
                      |  N1  +------------------+  N2  |
                      |      | component link 2 |      |
                      +--+---+                  +---+--+


                             Figure 3: Example

   The link type of the two component links are OTU2 and OTU3
   respectively.  The former has the capability of carrying ODU0, ODU1
   and ODUflex client signals, while the latter, ODU1, ODU3 and ODUflex.
   The TS type is 1.25Gbps and the supported priorities are:0, 3 and 7.

   In this example the two component links are bundled as a TE link but
   it could also be possible to consider each of them as a separate TE
   link.

   If the two component links are bundled together, N1 and N2 should
   assign a link local ID to the TE link and then N1 can get the link
   remote ID automatically or manually.

   N1 can generate an LSA to describe the above attributes of the TE
   link.  If we suppose the link IDs are unnumbered, the LSA should
   carry a link TLV with the following nested minimal sub-TLVs:



      < G.709 Digital Link > ::=  < Link Type > < Link ID > < Link
      Local/Remote Identifiers > < OTN ISCD >


   o Link Type sub-TLV: Defined in [RFC 3630], G.709 digital links are
   always type 1 - Point-to-point link.

   o Link ID sub-TLV: Defined in [RFC 3630], for point-to-point link,
   indicates the remote router ID.

   o Link Local/Remote Identifiers sub-TLV: Defined in [RFC 4203],
   indicates the local link ID and the remote link ID.

   o OTN ISCD sub-TLV: Defined in this document, carries the
   characteristic of this G.709 digital TE link.

   Just after the creation of the TE Link comprising the two component
   links, the OTN ISCD sub-TLV would be advertised as follows:





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       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SC = TDM      | Enc = G709    |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |1|0|0|0|1|0|0|1|T1.25|         |          Reserved             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU0(0) |0|               8 TS @ P0                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU0(0) |0|               8 TS @ P3                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU0(0) |0|               8 TS @ P7                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU1(1) |0|           8+32 = 40 TS @ P0                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU1(1) |0|           8+32 = 40 TS @ P3                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU1(1) |0|           8+32 = 40 TS @ P7                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU3(22)|0|               32 TS @ P0                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU3(22)|0|               32 TS @ P3                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU3(22)|0|               32 TS @ P7                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU2(21)|0|                8 TS @ P0                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU2(21)|0|                8 TS @ P3                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU2(21)|0|                8 TS @ P7                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |0|           8+32 = 40 TS @ P0                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |0|           8+32 = 40 TS @ P3                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |0|           8+32 = 40 TS @ P7                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|1|               32 TS @ P0                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|1|               32 TS @ P3                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|1|               32 TS @ P7                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                 Figure 4: Example - OTN-ISCD sub-TLV(to)

   Suppose that at time t1 an ODUflex LSP is created allocating 35 Gbps



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   at priority 3.  The OTN ISCD sub-TLV will be modified as follows:


















































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       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SC = TDM      | Enc = G709    |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |1|0|0|0|1|0|0|1|T1.25|         |          Reserved             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU0(0) |0|                 8 TS @ P0                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU0(0) |0|                 8 TS @ P3                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU0(0) |0|                 8 TS @ P7                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU1(1) |0|             8+32 = 40 TS @ P0               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU1(1) |0|              8+4 = 12 TS @ P3               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU1(1) |0|              8+4 = 12 TS @ P7               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU3(22)|0|                 32 TS @ P0                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU3(22)|0|                  0 TS @ P3                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU3(22)|0|                  0 TS @ P7                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU2(21)|0|                  8 TS @ P0                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU2(21)|0|                  8 TS @ P3                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODU2(21)|0|                  8 TS @ P7                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |0|             8+32 = 40 TS @ P0               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |0|              8+4 = 12 TS @ P3               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |0|              8+4 = 12 TS @ P7               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |1|                 32 TS @ P0                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |1|                  8 TS @ P3                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SType=ODUflex |1|                  8 TS @ P7                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                 Figure 5: Example - OTN-ISCD sub-TLV(t1)

   The last example shows how the prehemption is managed.  In



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   particular, if at time t2 a new 15 GBps ODUflex LSP with priority 0
   is created, the LSP with priority 3 is pre-empted and its resources
   (or part of them) are allocated to the LSP with higher priority.  The
   OTN ISCD sub-TLV is updated accordingly to Figure 6:















































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    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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | SC = TDM      | Enc = G709    |           Reserved            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |1|0|0|0|1|0|0|1|T1.25|         |          Reserved             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODU0   |0|                 8 TS @ P0                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODU0   |0|                 8 TS @ P3                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODU0   |0|                 8 TS @ P7                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODU1   |0|             8+20 = 28 TS @ P0               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODU1   |0|             8+20 = 28 TS @ P3               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODU1   |0|             8+20 = 28 TS @ P7               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=OTU3   |0|                  0 TS @ P0                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=OTU3   |0|                  0 TS @ P3                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=OTU3   |0|                  0 TS @ P7                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=OTU2   |0|                  8 TS @ P0                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=OTU2   |0|                  8 TS @ P3                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=OTU2   |0|                  8 TS @ P7                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|0|             8+20 = 28 TS @ P0               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|0|             8+20 = 28 TS @ P3               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|0|             8+20 = 28 TS @ P7               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|1|                 20 TS @ P0                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|1|                 20 TS @ P3                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  SType=ODUflex|1|                 20 TS @ P7                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                     Figure 6: Example - OTN-ISCD (t2)





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3.  Compatibility Considerations

   The legacy nodes that do not implement the extensions defined in this
   document are able, per [RFC3630] section 4, to ignore the LSA
   containing an OTN ISCD sub-TLV.  They will continue to flood the LSA
   to other neighbors, but will not use the information carried in this
   LSA.


4.  Security Considerations

   This document specifies the contents of Opaque LSAs in OSPFv2.  As
   Opaque LSAs are not used for SPF computation or normal routing, the
   extensions specified here have no direct effect on IP routing.
   Tampering with GMPLS TE LSAs may have an effect on the underlying
   transport (optical and/or SONET-SDH) network.  [RFC3630] suggests
   mechanisms such as [RFC2154] to protect the transmission of this
   information, and those or other mechanisms should be used to secure
   and/or authenticate the information carried in the Opaque LSAs.


5.  IANA Considerations

   TBD


6.  Contributors

      Xiaobing Zi

      Huawei Technologies

      F3-5-B R&D Center, Huawei Base

      Bantian, Longgang District

      Shenzhen 518129 P.R.China

      Email: zixiaobing@huawei.com



      Francesco Fondelli

      Ericsson

      Via Negrone 1/A




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      Genova - 16145

      Email: francesco.fondelli@ericsson.com



      Marco Corsi

      Altran Italia

      Via Negrone 1/A

      Genova - 16145

      EMail: marco.corsi@altran.it


7.  Acknowledgements

   The authors would like to thank Eric Gray for his precious comments
   and advices.


8.  References

8.1.  Normative References

   [MLN-EXT]  D.Papadimitriou, M.Vigoureux, K.Shiomoto, D.Brungard, J.Le
              Roux, "Generalized Multi-Protocol Extensions for Multi-
              Layer and Multi-Region Network (MLN/MRN)", February 2010.

   [OTN-FWK]  F.Zhang, D.Li, H.LI, S.Belotti, "Framework for GMPLS and
              PCE Control of G.709 Optical Transport networks, work in
              progress draft-ietf-ccamp-gmpls-g709-framework-02",
              July 2010.

   [OTN-INFO]
              S.Belotti, P.Grandi, D.Ceccarelli, D.Caviglia, F.Zhang,
              D.Li, "Information model for G.709 Optical Transport
              Networks (OTN), work in progress
              draft-bddg-ccamp-otn-g709-info-model-01", July 2010.

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

   [RFC2154]  Murphy, S., Badger, M., and B. Wellington, "OSPF with
              Digital Signatures", RFC 2154, June 1997.




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   [RFC2370]  Coltun, R., "The OSPF Opaque LSA Option", RFC 2370,
              July 1998.

   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630,
              September 2003.

   [RFC4201]  Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling
              in MPLS Traffic Engineering (TE)", RFC 4201, October 2005.

   [RFC4202]  Kompella, K. and Y. Rekhter, "Routing Extensions in
              Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC 4202, October 2005.

   [RFC4203]  Kompella, K. and Y. Rekhter, "OSPF Extensions in Support
              of Generalized Multi-Protocol Label Switching (GMPLS)",
              RFC 4203, October 2005.

   [RFC5250]  Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The
              OSPF Opaque LSA Option", RFC 5250, July 2008.

   [RFC5339]  Le Roux, JL. and D. Papadimitriou, "Evaluation of Existing
              GMPLS Protocols against Multi-Layer and Multi-Region
              Networks (MLN/MRN)", RFC 5339, September 2008.

8.2.  Informative References

   [G.709]    ITU-T, "Interface for the Optical Transport Network
              (OTN)", G.709 Recommendation (and Amendment 1),
              February 2001.

   [G.709-v3]
              ITU-T, "Draft revised G.709, version 3", consented
              by ITU-T on Oct 2009.

   [Gsup43]   ITU-T, "Proposed revision of G.sup43 (for agreement)",
              December 2008.














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Authors' Addresses

   Daniele Ceccarelli
   Ericsson
   Via A. Negrone 1/A
   Genova - Sestri Ponente
   Italy

   Email: daniele.ceccarelli@ericsson.com


   Diego Caviglia
   Ericsson
   Via A. Negrone 1/A
   Genova - Sestri Ponente
   Italy

   Email: diego.caviglia@ericsson.com


   Fatai Zhang
   Huawei Technologies
   F3-5-B R&D Center, Huawei Base
   Shenzhen 518129 P.R.China  Bantian, Longgang District
   Phone: +86-755-28972912

   Email: zhangfatai@huawei.com


   Dan Li
   Huawei Technologies
   F3-5-B R&D Center, Huawei Base
   Shenzhen 518129 P.R.China  Bantian, Longgang District
   Phone: +86-755-28973237

   Email: danli@huawei.com


   Yunbin Xu
   CATR
   11 Yue Tan Nan Jie
   Beijing
   P.R.China

   Email: xuyunbin@mail.ritt.com.cn






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   Sergio Belotti
   Alcatel-Lucent
   Via Trento, 30
   Vimercate
   Italy

   Email: sergio.belotti@alcatel-lucent.com


   Pietro Vittorio Grandi
   Alcatel-Lucent
   Via Trento, 30
   Vimercate
   Italy

   Email: pietro_vittorio.grandi@alcatel-lucent.com



































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