Advertisement of hierarchical and stitchable Label Switched Paths as Traffic Engineering Links draft-shiomoto-ccamp-lsp-hierarchy-bis-01.txt

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Advertisement of hierarchical and stitchable
Label Switched Paths as Traffic Engineering
Linksdraft-shiomoto-ccamp-lsp-hierarchy-bis-01.t
xt

• Mar. 24, 2006
• K. Shiomoto (NTT)
• R. Rabbat (Fujitsu)
• A. Ayyangar (Juniper Networks)
• A. Farrel (Old Dog Consulting)
• Z. Ali (Cisco Systems, Inc.)

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Target issue of the document

• To clarify the method how to signal the ingress
  TE Router-ID to the egress LSR for dynamic
  numbered FA.
• SenderTemplate-gt IPv4TunnelSenderAddress seemed
  to be a good place to hold the ingress TE
  Router-ID. But its use was already overloaded to
  exchange the interface address for numbered FA
  RFC 4206.
• Use of Session-gtExtended_Tunnel_ID was originally
  proposed as the solution in the Addressing I-D.
  But it conflicts with other uses of this field
  RFC 3209.
• For unnumbered FA, a new object
  LSP_TUNNEL_INTERFACE_ID is used to exchange the
  interface address RFC 3477.
• Use of the same object for numbered FA clears the
  overloaded use of SenderTemplate-gt
  IPv4TunnelSenderAddress. It can be used to hold
  the ingress TE Router-ID, making all FA LSP
  processing the same.

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Topics in this ID

• In designing the method to solve the issue, we
  sought the extensions for the areas related to FA
  as well.
• To identify the target IGP instance where the LSP
  is to be advertised.
• Advertising a TE link into a different instance
  of the IGP will be needed in some context of
  MLN/MRN.
• To indicate the usage of LSP advertisement.
• LSP can be advertised into the IP topology, the
  MPLS-TE topology or both, depending on the
  intended usage. Alternatively LSP can be used for
  only local traffic to the ingress/egress LSRs.

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Changes since Vancouver

• 1.2 LSP advertisement and Usage (added)
• RA Full routing adjacencies can be established
  over a bidirectional LSP. It is advertised into
  IP topology and can optionally be advertised into
  the MPLS topology.
• FA There is no IGP adjacency over the LSP.
  Notion of FA is equally applicable to the
  unidirectional as well as bidirectional LSPs.
• Local virtual link It is used for traffic local
  to the Ingress/ Egress LSRs. The LSP is neither
  advertised into the IP nor in MPLS topologies.
  Forwarding treatment is based on a local
  decision.
• 2.2 LSP advertisement and Usage Identification
  (added)
• The Egress node also needs to know if it needs to
  create a full routing adjacency or forwarding
  adjacency or just need to treat the LSP as a
  local virtual link.
• 1.3 Problem statement (modified)

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Received comments

• Document has matured but independent topics are
  covered.
• 4206-bis How to exchange TE Router-ID and
  interface address for numbered FA.
• LSP advertisement and Usage How to signal that
  the LSP need to be advertised or not and what
  kind of link (FA,RA).
• Target IGP instance How to indicate IGP instance
  where the LSP is advertised.
• Extensions for bundled link
• Parallel LSPs are advertised as
• separate TE links
• a single (bundled) TE link
• as several TE links (with each of them bundling
  two or more LSPs).

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Next step

• Should we split document?
• 4206-bis How to exchange link ID for numbered
  FA. ? Ask for WG document
• Others
• LSP advertisement and Usage How to signal that
  the LSP need to be advertised or not and what
  kind of link (FA,RA).
• Target IGP instance How to indicate IGP instance
  where the LSP is advertised.