draft-dolganow-pce-cost-object

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draft-dolganow-pce-cost-object

• authors
• Andrew Dolganow (Alcatel)
• Jean-Philippe Vasseur (Cisco)

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draft-dolganow-pce-cost-object

• Motivation
• Need to know TE-LSP path cost
• LSP Cost a metric that allows various
  applications to be executed on network (out of
  scope of our draft)
• Problem
• No way to know the cost by PCC in the current
  PCEP draft
• No way to know the cost of inter-domain TE-LSP
  using per-domain computations
• Solution
• Return the path cost as computed during PCE
  computation / accumulate the cost along the path
  (RSVP)
• Note Intend to split into PCE and RSVP drafts
  after the technical content stabilizes

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draft-dolganow-pce-cost-object

• New Cost object allows
• To keep cost processing centralized and
  minimizes changes
• Future expansion of functionality (hop-by-hop
  cost requests)
• Handling of TE-LSP cost in PCEP
• Move and fix the cost request (C flag in RP
  Object in PCReq) from PCEP I-D to this ID to keep
  functionality in one place
• Cost returned in PCRep message same cost object
  between PCEP and RSVP.
• Cost object is an optional object , processing
  govern by PR bits as per any other PCEP optional
  object

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draft-dolganow-pce-cost-object

• Accumulating TE-LSP path cost in RSVP
• Attributes TLV is being extended by a new Path
  cost flag to request the cost accumulation in
  RSVP Path message
• Same flag is added to RRO Attributes Subobject to
  indicate the cost accumulation took place
• Cost object is added by Tail-end LSR to
  accumulate path cost as part of RSVP Resv message
  processing
• Nodes add downstream link cost to collect the
  cost and set Path cost flag in RRO Attributes
  subobject
• Please provide comments to authors and PCE
  mailing list.