168th IETF, Prague, March 200768th IETF, Prague, March 2007

Graceful Shutdown in MPLS Traffic Engineering Networks

draft-ietf-ccamp-mpls-graceful-shutdown-02.txt

Zafar Ali (zali@cisco.com)Jean Philippe Vasseur (jpv@cisco.com)

Anca Zamfir (ancaz@cisco.com)

22268th IETF, Prague, March 200768th IETF, Prague, March 2007

Agenda

• How review comments received are addressed?

• Next Steps

33368th IETF, Prague, March 200768th IETF, Prague, March 2007

Graceful Shutdown and FRR/ Segment Recovery

• Graceful shutdown may be exercised using make-before-break or FRR/ segment recovery procedure.

• When PLR/ branch node receive a Path Error with Graceful Shutdown indication,

It MUST forward the Path Error to the Ingress node.

Based on a local decision, PLR/ Branch Node MAY trigger FRR/ segment recovery.

44468th IETF, Prague, March 200768th IETF, Prague, March 2007

Graceful Shutdown and Stitched LSP-es

• Component LSP segments are signaled as distinct TE LSPs in the control plane. In this example, the ABRs are responsible for "cross-connecting" the LSP segments.

• Ingress LSR of each LSP segment (S-LSP) performs make-before-break or triggers FRR/ segment protection to move traffic from segment affected by GS of a node/ link, to a new segment avoiding node/ link under GS.

In this example, the ABR-1 will be performing make-before-break or FRR/ segment protection operation when GS-1 event is triggered.

• Definition of the node that can perform GS procedure has been extended to include Ingress LSR of an S-LSP.

Area 1ABR-1

ABR-2 Area 2Area 0

GS-1

LSP Segment 1 LSP Segment 2 LSP Segment 3

55568th IETF, Prague, March 200768th IETF, Prague, March 2007

Graceful Shutdown and Bundled Links

• Local repair by using a different component link within the bundled TE link.

Based on a local decision, PLR/ branch node MAY trigger FRR/ segment recovery to recover from failure of a component link.

66668th IETF, Prague, March 200768th IETF, Prague, March 2007

Overloading error code from RFC 4736

• This ID inherits the Ingress behavior from RFC 4736, which says-

“Upon receiving an RSVP PERR message with Error code 25 and Error sub- code 7 (Local link maintenance required) or 8 (Local node maintenance required), the Head-end LSR SHOULD perform a TE LSP reoptimization”.

• This drafts relies on TE LSP reoptimization at Ingress but also extends the handling of this error code/ sub-code at PLR/ branch node (which includes the case where ingress node is PLR/ branch node).

77768th IETF, Prague, March 200768th IETF, Prague, March 2007

Next Steps

• Need to address a nit, which as received after the revision.

• Addressed all major outstanding comments.

• The ID has been quite stable since version 1 and authors would like to call for a last call (on a quick re-spin that will address the above-mentioned nit and any further comments).