167th IETF, San Diego, November 200667th IETF, San Diego, November 2006

Graceful Shutdown in MPLS Traffic Engineering Networks

draft-ietf-ccamp-mpls-graceful-shutdown-01.txt

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

Anca Zamfir (ancaz@cisco.com)

22267th IETF, San Diego, November 200667th IETF, San Diego, November 2006

Agenda

• Changes from the last version.

• How review comments received on the list are addressed?

33367th IETF, San Diego, November 200667th IETF, San Diego, November 2006

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 performs make-before-break 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 performs make-before-break operation when GS-1 event is triggered.

Area 1ABR-1

ABR-2 Area 2Area 0

GS-1

LSP Segment 1 LSP Segment 2 LSP Segment 3

44467th IETF, San Diego, November 200667th IETF, San Diego, November 2006

Graceful Shutdown and FRR/ Segment Recovery

• When PLR/ merge 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/ merge node MAY trigger FRR/ segment recovery.

55567th IETF, San Diego, November 200667th IETF, San Diego, November 2006

Graceful Shutdown and Bundled Links

• Local repair by using a different component link within the bundled TE link is NOT adapted.

If the local repair cannot be performed (due to lack of bandwidth), Ingress LSR is needed to move the traffic away from this bundled TE link.

It’s always a good practice to deal with exception cases using the same generic framework.

66667th IETF, San Diego, November 200667th IETF, San Diego, November 2006

Overloading error code from Loose Path Reoptimization Draft

• Expected behavior of the Ingress LSR is exactly in the two drafts.

• Both drafts require Ingress LSR to trigger Make-before-brake on the LSP affected by a Graceful showdown of a link/ node.

This ID inherits the Ingress behavior from draft-ietf-ccamp-loose-path-reopt-02.txt, 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”.

77767th IETF, San Diego, November 200667th IETF, San Diego, November 2006

Next Steps

• Addressed all outstanding comments.

• Need to decide if this ID should be Informational or Standard’s Track.

• The ID defines a new error sub-code for PathError. It also defines specific protocol behavior.

9 (TBA) Local component link maintenance required.

• After finalizing this debate and addressing any further comments, authors will do a quick a re-spin and request WG for the last call.