Advertisement%20of%20TE%20capabilities%20in%20IS-IS%20%20draft-vasseur-ccamp-isis-te-caps-00.txt%20J.P.%20Vasseur,%20S.%20Previdi%20

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Advertisement of TE capabilities in
IS-IS draft-vasseur-ccamp-isis-te-caps-00.txt
J.P. Vasseur, S. Previdi Cisco SystemsP. Mabey
QwestJL. Le Roux France Telecom

• IETF 59, Seoul 03/04/2003

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Content Overview

• This ID defines three sub-TLVs for the
  advertisement
• of TE capabilities in IS-IS
• PCED sub-TLV Discovery of PCE capabilities
• TE-MESH-GROUP sub-TLV Automatic Provisioning of
  TE mesh
• TE-NODE-CAP sub-TLV Discovery of TE node
  capabilities
• They are carried within the IS-IS CAPABILITY TLV
• defined in draft-vasseur-isis-caps-01.txt
• Flooding scope Single ISIS area/level or the
  entire domain

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Where does it fit in CCAMP charter

• Defines IS-IS Extensions useful for MPLS-TE and
  GMPLS
• Useful in various situations
• Inter-area, Inter-as, GMPLS, P2MP
• Should be discussed in CCAMP with a review of the
  IS-IS working group

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PCED Sub-TLV

• A PCE (Path Computation Element) computes paths
  for
• TE-LSPs it is not the Head-End for
• This can be an LSR, or a centralized tool not
  forwarding packets
• May be used in various situations inter-area/AS,
  Bandwidth Protection
• The PCE Discovery sub-TLV allows a PCE to
  dynamically advertise its capabilities to other
  LSRs
• This significantly simplifies LSR configuration
• Allows to dynamically detect a new PCE, or that a
  PCE is no longer active
• Structure
• PCE-ADDRESS sub-TLV
• PCE-CAPABILITY sub-TLV
• AS-Domain sub-TLV

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TE-MESH-GROUP Sub-TLV

• TE Mesh-Goup Group of LSRs fully meshed by
  TE-LSPs
• Contained within a level/area or spanning
  multiple levels/areas
• Identified by a mesh-group number
• The TE-MESH-GROUP sub-TLV allows an LSR to
  dynamically advertise its desire to join a TE
  mesh group
• This allows automatic provisioning of a TE-LSP
  mesh
• Solves the 0(n2) configuration issue
• Structure
• Mesh-group number
• Tail-End Address
• Tail-End name

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TE-NODE-CAP sub-TLV

• Set of flags corresponding to TE capabilities of
  the LSR
• Currently only one flag defined
• Capability to be a branch LSR of a P2MP LSP
• Additional flags should be defined latter

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Procedure

• These sub-TLVs are carried within the
• IS-IS CAPABILITY TLV
• The Scope flag controls the flooding scope of the
  TLV
• S0 Local scope (single level/area)
• S1 wide scope (entire domain)
• Local scope TE capabilities carried within a
  local scope
• IS-IS CAPABILITY TLV (i.e. having the Scope
  flag cleared)
• Wide scope TE capabilities carried within a wide
  scope IS-IS CAPABILITY TLV (i.e. having the
  Scope flag set)

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Next Steps

• Defines useful sub-TLVs allowing to enable
  features required by several Service Providers
• Ongoing implementations
• We request to accept this ID as a WG document