Graceful%20Shutdown%20in%20MPLS%20Traffic%20Engineering%20Networks%20%20draft-ali-ccamp-mpls-graceful-shutdown-03.txt

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Graceful Shutdown in MPLS Traffic Engineering
Networks draft-ali-ccamp-mpls-graceful-shutdown-
03.txt
Zafar Ali (zali_at_cisco.com) Jean Philippe Vasseur
(jpv_at_cisco.com) Anca Zamfir (ancaz_at_cisco.com)
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History of the Draft

• It was first presented at IETF 60 in August 2004.
  
• There is a general agreement on the requirements
  and the Signaling Solution.
• We need to close on a minor detail in the Routing
  Solution (discussion focus for today).

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Motivation for using the link-attribute sub-TLV

• The draft proposes to use link-attribute sub-TLV
  with local maintenance required bit, as defined
  in http//www.ietf.org/internet-drafts/draft-ietf-
  isis-link-attr-01.txt.
• Draft discusses the possibility of using
  (MAX-METRIC, Zero Bandwidth) based solution but
  also points out some issues associated with this
  solution-
• A link may end-up with max metric for multiple
  reasons and without the link attribute there is
  no way a node can tell what the reason is, e.g. a
  restarting node advertises the max matrices
  RFC4203 , RFC4205.
• A resource under graceful shutdown can be used as
  a last resort resource.
• The ID states the following backward
  compatibility note-
• "to deal with nodes not compliant with this
  document (i.e., does not implement link attribute
  sub-TLV based solution), the node initiating
  graceful shutdown MAY originate the TE LSA/LSP
  containing Link TLV with 0 unreserved bandwidth,
  Traffic Engineering metric set to 0xffffffff, and
  if the Link is non-PSC then also with 0 as Max
  LSP Bandwidth..

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Next Steps

• There is a general agreement on the requirements
  and signaling solution.
• We would like to close on routing solution
  quickly.
• The work is within the Scope of CCAMP.
• We would like to request WG to accept this ID as
  a WG document.