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

Versions: 00 01

          Internet Draft                               Hang Liu
          draft-liu-gmpls-ospf-restoration-00.txt      Dimitrios Pendarakis
          Expires: April 2003                          Bala Rajagopalan
                                                       Nooshin Komaee
                                                       Tellium, Inc.
                                                       October 2002
          
              OSPF-TE Extensions in Support of Shared Mesh Restoration
          
                      <draft-liu-gmpls-ospf-restoration-00.txt>
          
          Status of this Memo
          
             This document is an Internet-Draft and is in full conformance
             with all provisions of Section 10 of RFC2026.
          
             Internet-Drafts are working documents of the Internet
             Engineering Task Force (IETF), its areas, and its working
             groups.  Note that other groups may also distribute working
             documents as Internet-Drafts.
          
             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."
          
             The list of current Internet-Drafts can be accessed at
             http://www.ietf.org/ietf/1id-abstracts.txt
          
             The list of Internet-Draft Shadow Directories can be accessed
             at http://www.ietf.org/shadow.html.
          
          Abstract
          
             This document describes extensions to the OSPF-TE routing
             protocol in support of path computation for shared mesh
             restoration. New optional sub-TLVs are added to the link TLV
             of the Traffic Engineering (TE) LSA so that the sharing
             information of the restoration resource on the TE link
             reserved for shared mesh restoration is disseminated. The
             extensions supports both SRLG-disjoint and node-disjoint
             paths.
          
          
          
          
          
          Liu, et. al.             Expires - April 2003                 [Page 1]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
          
          
          1. Introduction
          
             In shared mesh restoration [1,2,3,4], the restoration LSP is
             pre-computed and its resource is reserved along the path
             through signaling protocols [5, 6, 7]. However no cross-
             connections are performed along the restoration path. The
             complete establishment of the restoration LSP occurs only
             after the working LSP fails, and requires some additional
             signaling. The common restoration resource reserved at a node
             or on a TE link may be shared by multiple restoration LSPs to
             restore multiple working LSPs. In order to avoid contention
             for the reserved restoration resource (bandwidth or channel)
             during a single SRLG/node failure, two restoration LSPs may
             share the common reserved restoration resource only if their
             respective working LSPs are mutually SRLG/node disjoint. One
             failure then does not disrupt both working LSPs
             simultaneously.
          
             Shared mesh restoration achieves efficient utilization of
             network resources by sharing the restoration resource. It can
             achieve reasonably fast switching time and guarantees
             successful recovery from a single SRLG/node failure.
             The resource reserved for restoration can even be used by the
             other path to carry the extra traffic during normal operation
             mode (i.e. while there are no failure on the working LSPs). Of
             course, the restoration path needs to be activated when the
             working path fails. It may result in a switching time longer
             than the dedicated 1+1 protection. Furthermore, since multiple
             restoration LSPs may share the common reserved restoration
             resource. The contention may occur on the reserved restoration
             resource when more than one of the working paths fails
             simultaneously due to multiple failures.
          
             This document specifies extensions to OSPF [8] in support of
             carrying link state information for the path computation for
             shared mesh restoration. It is based on the existing OSPF
             routing extensions required to support Traffic Engineering and
             GMPLS [9, 10, and 11]. Similar extensions described here can
             also be made to IS-IS. These extensions are initially focused
             on transport networks; however they are not meant to be
             exclusively for the transport networks.
          
          
          
          
          
          Liu, et. al.              Expires - April 2003                [Page 2]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
          
          2. Required Information
          
             In shared mesh restoration, multiple restoration LSPs can
             share the same reserved restoration resource on their common
             TE links only if the sets of SRLGs and/or nodes traversed by
             their respective working LSPs are disjoint in order to
             guarantee recovery from a single SRLG failure or a single node
             failure. This imposes additional constraints on the path
             computation. To compute the restoration LSP for the shared
             mesh restoration, the path computation module needs to have
             the restoration resource sharing information on the links in
             the network. In general, the more detail information is
             available, the better results the path computation algorithms
             can achieve. On the other hand, in order to reduce the amount
             of information handled by OSPF and improve the routing
             scalability, it may be desirable to aggregate the information
             on a TE link (bundle) [12]. To support path computation for
             shared mesh restoration, all or some information below can be
             disseminated by routing protocol.
          
             (1)  Summarized information about the restoration resource
             sharing on a TE link for shared mesh restoration, such as the
             total number of restoration LSPs sharing the restoration
             resource reserved on the TE link for shared mesh restoration,
             the total number of SRLGs recovered by the reserved
             restoration resource on the TE link, the total number of nodes
             recovered by the reserved restoration resource on the TE link,
             the total sharable restoration bandwidth at each priority
             level.
          
             (2)  The list of SRLGs recovered by the reserved restoration
             resource on the TE link and their respective sharable
             restoration bandwidth if the SRLG-disjointness is required to
             guarantee recovery in the event of a single SRLG failure.
          
             (3)  The list of nodes recovered by the reserved restoration
             resource on the TE link and their respective sharable
             restoration bandwidth if the node-disjointness is also
             required to guarantee recovery in the event of a single node
             failure. By distinguishing node failure restoration from SRLG
             failure restoration, it provides the network operator with
             options to offer different levels of services and uses the
          
          
          
          
          
          Liu, et. al.          Expires - April 2003                    [Page 3]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
             network resource more efficiently as explained later in this
             section.
          
             The list of SRLGs/nodes recovered by the TE link is defined as
             the union of SRLGs/nodes traversed by all the working LSPs
             whose respective restoration LSPs share the reserved
             restoration resource on this TE link. The common reserved
             restoration resource (e.g. an OC-48 channel) can be reused by
             a restoration LSP to recover a working LSP if no SRLG/node
             passed over by its working LSP appears in the list of
             SRLGs/nodes already recovered by the restoration resource. The
             sharable restoration bandwidth for a SRLG and/or node
             indicates the available restoration bandwidth on the TE link
             that can be reserved for recovering this SRLG/node failure. If
             a working LSP only traverses one SRLG, the available
             restoration bandwidth that its restoration LSP can share on
             this TE link is the sharable restoration bandwidth for this
             SRLG. When a working LSP traverses multiple SRLGs, the
             sharable restoration bandwidth available for its restoration
             LSP may become smaller on this TE link. It is the same case
             for a given node when the node-disjointness is required.
          
             The total sharable restoration bandwidth is the bandwidth
             reserved on the TE link for restoration, which is the union of
             the sharable restoration bandwidth for all SRLGs and nodes.
          
             A lot of equipment has its own recovery and high availability
             requirements. The operator may choose to guarantee recovery
             only from a single SRLG failure or from a SRLG/node failure
             based on the requirements of the end user applications. For
             example, an application requires 99.999% availability. The
             node can meet this requirement because it has its own
             equipment recovery mechanism. However the fiber links cannot
             meet this requirement. In order to meet the application
             availability requirements, the shared mesh restored LSP
             carrying this application traffic must guarantee recovery from
             a single SRLG failure, but it does not have to guarantee
             recovery from a single node failure. Then the common
             restoration resource can be reserved to restore two working
             LSPs that traverse a common node (no node-disjoint constraint);
             i.e. less constraints are required to compute the restoration
             path.By distinguishing node failure recovery guarantee and SRLG
             failure recovery guarantee, the operators can offer different
          
          
          
          
          
          Liu, et. al.                 Expires - April 2003             [Page 4]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
             levels of services based on performance requirements of the end
             user applications and utilize the network resource more
             efficiently.
          
          3. OSPF Extensions to Support Path Computation for Shared Mesh
             Restoration
          
             It is desirable to carry the sharing information of the
             restoration resource on a TE link with the OSPF so that the
             information may be used by the path computation algorithm to
             compute the restoration path for shared mesh restoration. This
             section specifies the extensions to OSPF-TE in support of
             shared mesh restoration.
          
             OSPF traffic engineering extensions [9] and GMPLS extensions
             [10,11] make use of the Opaque LSA [13]. An Opaque LSA, called
             Traffic Engineering LSA is defined to carry the additional
             attributes related to traffic engineering and GMPLS links. The
             information in the TE LSAs can be used to build an extended TE
             link state database just as router LSAs are used to build a
             regular link state database. The extensions here are based
             upon the OSPF-TE and GMPLS extensions, specifically, we add
             the following sub-TLVs to the link TLV of the TE LSA.
          
          3.1 Restoration Information Summary
          
             Restoration Information Summary sub-TLV specifies the sharing
             information of the restoration resource reserved for shared
             mesh restoration on the TE link. The format of the Restoration
             Information Summary sub-TLV is as follows
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          Liu, et. al.           Expires - April 2003                   [Page 5]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
           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(TBA)           |         Length                  |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          | #Shared Restoration LSPs      |       #SRLGs recovered        |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |   #Nodes recovered            |       Reserved           |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 0       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 1       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 2       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 3       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 4       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 5       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 6       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Total Sharable Restoration Bandwidth at priority 7       |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          
             Type: 16 bits
                   The type of this sub-TLV is TBA.
          
             Length: 16 bits
                   The length of this sub-TLV is 40 octets.
          
             #Shared Restoration LSPs: 16 bits
                   This field indicates the number of restoration LSPs
                   sharing the bandwidth reserved for the mesh restoration
                   on this TE link.
          
          
          
             #SRLGs recovered: 16 bits
          
          
          
          
          
          
          
          Liu, et. al.            Expires - April 2003                  [Page 6]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
                   This field indicates the number of SRLGs recovered by
                   the TE link. The SRLGs here includes all distinct SRLGs
                   traversed by all the working LSPs whose respective
                   restoration LSPs shares the reserved restoration
                   bandwidth on this TE link. Zero means that this
                   information is not available.
          
             #Nodes recovered: 16 bits
                   This field indicates the number of nodes recovered by
                   the TE link. The nodes here include all distinct nodes
                   traversed by all the working LSPs whose respective
                   restoration LSPs shares the reserved restoration
                   bandwidth on this TE link. Zero means that this
                   information is not available.
          
             Total Sharable Restoration Bandwidth at priority 0-7: 32 bits
                   Total Sharable Restoration Bandwidth specifies the
                   bandwidth that has been allocated for shared mesh
                   restoration at each of the eight priority levels. The
                   bandwidth might have been reserved by one or more shared
                   restoration LSP. It is encoded in the IEEE floating
                   point format, with 4 octets per priority.
          
             The Restoration Information Summary sub-TLV is optional and if
             a LSA doesnÆt carry the Restoration Information Summary sub-
             TLV, then it means that the information is unknown.
          
          3.2 SRLG Sharable Restoration Bandwidth
          
             SRLG Sharable Restoration Bandwidth sub-TLV identifies the
             sharable restoration bandwidth range for a SRLG on this TE
             link. By allowing to specify a range instead of a fixed value,
             it may reduce the amount of information handled by the routing
             protocol. If the lower bound is equal to the upper bound of
             the range, it indicates a fixed value of the sharable
             restoration bandwidth. Its format is as follows
          
          
          
          
          
          
          
          
          
          
          
          
          Liu, et. al.            Expires - April 2003                  [Page 7]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
           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(TBA)           |         Length                  |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |  Priority     |               Reserved                        |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Sharable Restoration Bandwidth Lower Bound               |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |      Sharable Restoration Bandwidth Upper Bound               |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |                        SRLG 1                                 |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |                      ... ...                                  |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |                        SRLG N                                 |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          
          
               Type: 16 bits
                    The type of this sub-TLV is TBA.
          
               Length: 16 bits
                    The length of this sub-TLV is the length of value field
                    in octets.
          
               Priority: 8 bits
                    This field indicates the priority of sharable
                    restoration bandwidth. The SRLG sharable restoration
                    bandwidth can be encoded per priority. If the SRLG
                    sharable restoration bandwidth is not encoded per
                    priority, the value of the priority field is set to
                    0xFF, which means the sharable restoration bandwidth is
                    the same for all priorities.
          
               Sharable Restoration Bandwidth Lower Bound and Upper Bound:
               32 bits
          
          
          
          
          
          
          Liu, et. al.          Expires - April 2003                    [Page 8]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
                    The Sharable Restoration Bandwidth Lower Bound and
                    Sharable Restoration Bandwidth Upper Bound specify a
                    range for sharable restoration bandwidth. The sharable
                    restoration bandwidth for each of SRLG in the following
                    list falls into this range, i.e. Sharable Restoration
                    Bandwidth Lower Bound <= sharable restoration bandwidth
                    for SRLG N < Sharable Restoration Bandwidth Upper
                    Bound. If the lower bound is equal to the upper bound,
                    a fixed value of sharable restoration bandwidth is
                    specified and the sharable restoration bandwidth for
                    each of SRLGs in the following list is equal to this
                    value.
          
               SRLG: 32 bits
                    The value is a list of 32-bit numbers, each of number
                    identifies a SRLG.
          
             The SRLG Sharable Restoration Bandwidth sub-TLV is optional
             and if a LSA doesnÆt carry any SRLG Sharable Restoration
             Bandwidth sub-TLV, then it is assumed that the information is
             unknown. There may be more than one SRLG Sharable Restoration
             Bandwidth sub-TLVs in the LSA. However if there are one or
             more SRLG Sharable Restoration Bandwidth sub-TLVs in the LSAs,
             the sharable restoration bandwidth for the SRLGs not listed in
             these SRLG sharable restoration bandwidth sub-TLVs is assumed
             to be equal to the total sharable restoration bandwidth at
             that priority on this TE link.
          
          3.3 Node Sharable Restoration Bandwidth
          
             Node Sharable Restoration Bandwidth sub-TLV identifies the
             sharable restoration bandwidth range that is reserved on this
             TE link for sharing by restoration LSPs to recover a node
             failure on their working path. It can be used by the path
             computation algorithms to compute the restoration LSP when it
             is required that multiple restoration LSP can share the common
             restoration resource on their common TE links only if their
             respective working LSPs are node disjoint. Its format is as
             follows
          
          
          
          
          
          
          
          Liu, et. al.          Expires - April 2003                    [Page 9]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
           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(TBA)           |         Length                  |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |  Priority     |               Reserved                        |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |       Sharable Restoration Bandwidth Lower Bound              |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |       Sharable Restoration Bandwidth Upper Bound              |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |                        Node1 ID                               |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |                      ... ...                                  |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          |                        NodeN ID                               |
          +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
          
          
               Type: 16 bits
                    The type of this sub-TLV is TBA.
          
               Length: 16 bits
                    The length of this sub-TLV is the length of value field
                    in octets.
          
               Priority: 8 bits
                    This field indicates the priority of sharable
                    restoration bandwidth. The node sharable restoration
                    bandwidth can be encoded per priority. If the node
                    sharable restoration bandwidth is not encoded per
                    priority, the value of the priority field is set to
                    0xFF, which means the sharable restoration bandwidth is
                    the same for all priorities.
          
               Sharable Restoration Bandwidth Lower Bound and Upper Bound:
               32 bits
          
          
          
          
          
          
          Liu, et. al.             Expires - April 2003                [Page 10]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
                    The Sharable Restoration Bandwidth Lower Bound and
                    Sharable Restoration Bandwidth Upper Bound specify a
                    range for sharable restoration bandwidth reserved on a
                    TE link. The sharable restoration bandwidth for each of
                    node in the following list falls into this range, i.e.
                    Sharable Restoration Bandwidth Lower Bound <= sharable
                    restoration bandwidth for Node N < Sharable Restoration
                    Bandwidth Upper Bound. If the lower bound is equal to
                    the upper bound, a fixed value of sharable restoration
                    bandwidth is specified and the sharable restoration
                    bandwidth for each of nodes in the following list is
                    equal to this value.
          
               Node ID:  32 bits
                    The value is a list of 32-bit numbers, each of number
                    identifies a node.
          
             The Node Sharable Restoration Bandwidth sub-TLV is optional
             and if a LSA doesnÆt carry any Node Sharable Restoration
             Bandwidth sub-TLV, then it is assumed that the information is
             unknown. There may be more than one Node Sharable Restoration
             Bandwidth sub-TLVs in the LSA. However if there are one or
             more Node Sharable Restoration Bandwidth sub-TLVs in the LSAs,
             the sharable restoration bandwidth for the nodes not listed in
             these Node sharable restoration bandwidth sub-TLVs is assumed
             to be equal to the total sharable restoration bandwidth at
             that priority on this TE link.
          
          4. Acknowledgments
          
             The authors would like to thank Ramu Ramamurthy, Eric
             Bouillet, Ahmet Akyamac, Jean-Francois Labourdette, and Sid
             Chaudhuri for extremely valuable discussions on path
             computation algorithms and useful input that they have provided
             in this work.
          
          
          
          
          
          
          
          
          
          
          
          Liu, et. al.             Expires - April 2003                [Page 11]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
          5. References
          
            1. D. Papadimitriou, et al., "Analysis Grid for GMPLS-based
               Recovery Mechanisms," Internet Draft, work in progress,
               draft-papadimitriou-ccamp-gmpls-recovery-analysis-00.txt,
               April 2002.
            2. E. Mannie, et al., "Recovery (Protection and Restoration)
               Terminology for GMPLS," Internet Draft, work in progress,
               draft-mannie-gmpls-recovery-terminology-00.txt, February
               2002.
            3. J. P. Lang, B. Rajagopalan, et al., "Generalized MPLS
               Recovery Functional Specification," Internet Draft, work in
               progress, draft-bala-gmpls-recovery-functional-00.txt,
               August, 2002.
            4. G. Li, et al., "RSVP-TE Extensions for Shared-Mesh
               Restoration in Transport Networks," Internet Draft, work in
               progress, draft-li-shared-mesh-restoration-01.txt, November
               2001.
            5. P. Ashwood-Smith, et al, "Generalized MPLS - Signaling
               Functional Description," Internet Draft, work in progress,
               draft-ietf-mpls-generalized-signaling-08.txt, April 2002.
            6. P. Ashwood-Smith, et al., "Generalized MPLS û RSVP-TE
               Extensions," Internet Draft, work in progress, draft-ietf-
               mpls-generalized-rsvp-te-07.txt, April 2002.
            7. P. Ashwood-Smith, et al., "Generalized MPLS Signaling - CR-
               LDP Extensions," Internet Draft, work in progress, draft-
               ietf-mpls-generalized-cr-ldp-06.txt, April 2002.
            8. J. Moy, "OSPF Version 2", RFC 2328, April 1998.
            9. D. Katz, et al., "Traffic Engineering Extensions to OSPF",
               Internet Draft, work in progress, draft-katz-yeung-ospf-
               traffic-06.txt, October 2001.
            10. K. Kompella, et al., "Routing Extensions in Support of
               Generalized MPLS," Internet Draft, work in progress, draft-
               ietf-ccamp-gmpls-routing-04.txt, April 2002.
            11. K. Kompella, et al., "OSPF Extensions in Support of
               Generalized MPLS", Internet Draft, work in progress, draft-
               ietf-ccamp-ospf-gmpls-extensions-05.txt, April 2002.
          
          
          
          
          
          
          Liu, et. al.            Expires - April 2003                 [Page 12]


          draft-liu-gmpls-ospf-restoration-00.txt                   October 2002
          
          
          
            12. K. Kompella, et al., "Link Bundling in MPLS Traffic
               Engineering," Internet Draft, work in progress, draft-
               kompella-mpls-bundle-05.txt, February 2001.
            13. Coltun, R., "The OSPF Opaque LSA Option," RFC 2370,
               July 1998.
          
          
          6. Authors' Addresses
          
             Hang Liu
             Dimitrios Pendarakis
             Bala Rajagopalan
             Nooshin Komaee
             Tellium, Inc.
             2 Crescent Place
             Oceanport, NJ 07757
             USA
             Phone: +1 732 923 4100
             Email: {hliu, dpendarakis, braja, nkomaee}@tellium.com
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          
          Liu, et. al.              Expires - April 2003               [Page 13]
          

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