Exclude Routes - Extension to RSVP-TE

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Exclude Routes - Extension to RSVP-TE

• IETF 56, San Francisco
• draft-lee-ccamp-rsvp-te-exclude-route-02.txt
• Cheng-Yin Lee (cheng-yin.lee_at_alcatel.com)
• Adrian Farrel (afarrel_at_movaz.com)
• Stefaan De Cnodder (stefaan.de_cnodder_at_alcatel.be)
  

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Why in the CCAMP WG?

• Charter item
• Define signaling mechanisms for protection,
  diverse routing
• Increasing interest in managing route exclusions
  for diversity, multi-AS and distributed routing
  responsibility
• This is an extension to MPLS but is generalized
  and should form part of GMPLS

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Why do we need route exclusion?

• Some signaled EROs are not strict explicit
• Loose hops
• Abstract nodes such as prefixes and AS numbers
• Where is path computation performed?
• Offline or at the ingress
• Protection domains
• Limited visibility of routing information
• Georges overlay draft
• Path computation request signaling (JP Vasseur)
• Multiple areas (NOT a prerequisite for this
  draft)
• MPLS-TE-MIB allows route exclusions

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Summary of the Schemes

• List nodes, links, resources, SRLGs that must not
  be used anywhere on the path
• Exclude Route Object (XRO) looks like an ERO
• List nodes, links, resources, SRLGs that must not
  be used between a pair of hops in an ERO
• New Exclude Route Subobjects (EXRS) in ERO
• Control whether exclusion is mandatory or desired

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Changes in this draft

• Identification of new work items
• Addition of further examples and explanation of
  the applicability
• Reduction of the length of the XRO and EXRS
  subobjects
• Identification of the scope of relevance of
  exclusions so that they may be omitted from
  signaled messages, or at least from path
  computations, when they are not relevant
• Ability to exclude unnumbered links
• Convergence of SRLG identification with formats
  defined in other drafts
• Simplify!

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Actions

• Useful feedback recently - thanks
• We solicit input from providers on how they avoid
  resources
• Look for convergence with JPs draft
• Discuss work items today
• Email me to join us
• Updates and re-publish
• Request to be adopted by WG
• TEWG doing multi-AS/area requirements?
• CCAMP will do multi-AS/area???
• But this is not just a multi-AS/area thing