Graceful Shutdown in MPLS Traffic Engineering Networks draft-ietf-ccamp-mpls-graceful-shutdown-02.txt

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Graceful Shutdown in MPLS Traffic Engineering
Networks draft-ietf-ccamp-mpls-graceful-shutdown
-02.txt
Zafar Ali (zali_at_cisco.com) Jean Philippe Vasseur
(jpv_at_cisco.com) Anca Zamfir (ancaz_at_cisco.com)
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Agenda

• How review comments received are addressed?
• Next Steps

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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.

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Graceful Shutdown and Stitched LSP-es
ABR-1
Area 0
Area 1
Area 2
ABR-2
GS-1
LSP Segment 3
LSP Segment 1
LSP Segment 2

• 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.

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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.

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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).

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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).