mpls draft-kini-restoration-shared-backup-00.txt

[Curtis Villamizar <curtis@curtis-lt.avici.com>]

NAME OF I-D:

  <http://www.ietf.org/internet-drafts/draft-kini-restoration-shared-backup-00.txt>

SUMMARY:
 
  "Shared backup Label Switched Path restoration", Curtis Villamizar, T. V.
  Lakshman, Sriganesh Kini, Murali Kodialam, 11/08/2000, 
  <draft-kini-restoration-shared-backup-00.txt>                            

    Traffic engineering using MPLS involves the setting up of label
    switched paths (LSP) possibly with explicit routing and with
    bandwidth guarantees (for label switched paths). The reliability of
    these LSPs can be increased by providing a backup LSP onto which
    traffic can be switched upon failure of an element in the path of the
    active LSP. Backup LSPs can be routed in a way that bandwidth can be
    shared between backup links of more than one active path while still
    guaranteeing recoverability for a set of failures. This sharing greatly
    increases the network efficiency, thereby increasing the number of LSPs
    that can be carried while maintaining guarantees. Algorithms which can
    route such recoverable LSPs while using only aggregate network usage 
    information are being developed.
    This informational draft illustrates the concept of sharing links along
    backup paths and examines the requirements from link state
    information and the signaling functions.                               

RELATED DOCUMENTS:

  "ReSerVation Protocol with Traffic Engineering extensions.Extension for
  Label Switched Path estoration", Curtis Villamizar, T. V. Lakshman,
  Sriganesh Kini, Murali Kodialam, 11/08/2000,
  <draft-kini-rsvp-lsp-restoration-00.txt>

  "Intermediate System to Intermediate System (IS-IS)     protocol
  extensions for Label Switched Path restoration", Curtis Villamizar, T. V.
  Lakshman, Sriganesh Kini, Murali Kodialam, 11/08/2000,
  <draft-kini-isis-lsp-restoration-00.txt>

  "Open Shortest Path First (OSPF) protocol extensions for Label Switched
  Path restoration", Curtis Villamizar, T. V. Lakshman, Sriganesh Kini,
  Murali Kodialam, 11/08/2000, <draft-kini-ospf-lsp-restoration-00.txt>

  "A Method for MPLS LSP Fast-Reroute Using RSVP Detours", Der-Hwa Gan,
  Ping Pan, Kireeti Kompella, Arthi Ayyangar, 04/11/2001,
  <draft-gan-fast-reroute-00.txt>

  "RSVP Label Allocation for Backup Tunnels", George Swallow, R Goguen,
  11/30/2000, <draft-swallow-rsvp-bypass-label-01.txt>

WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK:

  It is in MPLS but the picture is broken.  GMPLS == C control and
  MPLS fits under GMPLS and over the others (OPT, TDM, ATM, FR, etc).

WHY IS IT TARGETED AT THIS WG:

  This work is generic to MPLS restoration and not specific to any
  underlying technology, such as optical switching.

JUSTIFICATION:

  The signaling and bandwidth accounting technique described in this
  document provides sharing of bandwidth used for backup LSPs or LSPs
  using MPLS local-protect as defined in
  <draft-gan-fast-reroute-00.txt> or bypass LSP as defined in
  <draft-swallow-rsvp-bypass-label-01.txt>.  The inability to share
  backup bandwidth where backups are intended to cover single failures
  and where backups are covering failures that are expected not to be
  correlated (no common SRLG) is a shortcoming of current approaches
  that is addressed here.

  The technique is generally applicable to MPLS and accommodated but
  is not specific to MPLS used in optical networks, rings, switched
  services, or TDM.  Therefore the MPLS WG would be slightly preferred
  over CCAMP.  If MPLS restoration is supposed to happen in CCAMP,
  then it belongs in CCAMP.