A Path Computation Element PCE Application for Precomputed

A Path Computation Element (PCE) Application for Pre-computed Routing draft-bao-pce-pre-configured-routing-00. txt Yuanlin Bao Xihua Fu Gang Xie ZTE Corporation Page - 1 IETF 76, Hiroshima, November 8 -13, 2009

Background • Traditional Pre-configured route – pre-configured by NMS – not used until primary route fails – usually not be updated • unavailablity • need to be checked before used – faster restoration can be achieved • Pre-computed route – Pce-based “pre-configured” route • “pre-configured route” is misunderstanding in 00 version, it will be substituted by “pre-computed route” in 01 version – PCC asks for 2 (or more) routes, the first one will be signaled, the other will be kept in case a failure happens on the first route – requested/cancelled by PCC – dynamically updated according to network failure or the configured policy by pce – provider can offer better service for customer Page - 2 IETF 76, Hiroshima, November 8 -13, 2009

Application compute a primary route{A, B, C, G} route and a prepre-computed route to {A, D, F, G} node G request a service to Client 2 with a precomputed routing service level pre-computed route {A, D, F, G} is affected, find another one. . . new pre-computed route {A, D, E, F, G} Primary route {A, B, C, G} Pre-computed route {A, D, F, G} {A, D, E, F, G} Oh, link BC is cut. . . not scared! signal. Aha! the I’m service signal the service I have pre-computed with the preroute {A, D, E, F, G} computed Page - 3 IETF 76, Hiroshima, November 8 -13, 2009

Requirements • PCC – SHOULD be able to request pre-computed routing service – SHOULD be able to cancel pre-computed routing service • PCE – SHOULD be able to store the information of pre-computed routing service – SHOULD be able to re-compute the pre-computed route according to network states change and other configured policy – SHOULD be able to send the result of re-computed precomputed route without PCC request Page - 4 IETF 76, Hiroshima, November 8 -13, 2009

PCEP extension • New Flag Of RP Object – Pre-Computed Routing Service Flag (bit 20) – PCC use it to request pre-computed routing service – PCE use it to send pre-computed route • Extension to Notification Object – Notification-type=3: Pre-Computed Routing Service cancelled • Notification-value=1: PCC cancels one pre-computed routing service • Notification-value=2: PCC cancels all pre-computed routing services it requested Page - 5 IETF 76, Hiroshima, November 8 -13, 2009

Summary & Next Steps • The term “pre-configured route” is misunderstanding – it will be substituted by “pre-computed route” • Draft will continue to evolve: – Evaluating requirements – Evaluating PCEP extentions – Refine it according to the feedback from meeting or mailing list • Comments are always appreciated Page - 6 IETF 76, Hiroshima, November 8 -13, 2009