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@alcatel.com) Adrian Farrel (afarrel@movaz.com)

Stefaan De Cnodder (stefaan.de_cnodder@alcatel.be)

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

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– George’s overlay draft– Path computation request signaling (JP Vasseur)– Multiple areas (NOT a prerequisite for this draft)

• MPLS-TE-MIB allows route exclusions

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

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!

Actions• Useful feedback recently - thanks• We solicit input from providers on

how they avoid resources• Look for convergence with JP’s 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