Operating VCAT and LCAS with GMPLS

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Operating VCAT and LCAS with GMPLS

• draft-bernstein-ccamp-gmpls-vcat-lcas-01
• Greg Bernstein gregb_at_grotto-networking.com
• Diego Caviglia Diego.Caviglia_at_marconi.com
• Richard Rabbat richard_at_us.fujitsu.com
• Slides prepared with Huub van Helvoort

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A VCAT example with Ethernet Service
End-to-end Ethernet Service
Signal adaptation consistence
CE
CE
Transport resource selection
Transport Network
SNP
PE
PE
Note Requires Consistent Adaptation
functionality at Ingress and Egress Nodes
Network connections supporting Ethernet Service
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Virtual Concatenation VCAT

• A general inverse multiplexing technique that can
  be applied to several transport technologies
  including SONET/SDH, PDH, and OTN
• Allows a better bandwidth fit of Ethernet client
  layer to transport
• e.g. 7 STS-3c circuits (155 Mbps each) to carry
  GigE, instead of 1 STS-48 (2.5 Gbps)
• Not restricted to Ethernet applies to FC, etc.
• Currently some support in GMPLS, however several
  desirable scenarios appear unsupported.

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Link Capacity Adjustment Scheme LCAS

• Without LCAS, the existing service has to be
  terminated and another one has to be established
  between the same Ingress Node and Egress Node
• LCAS enhancement to VCAT to allow the hitless
  increase and decrease of used bandwidth
• Allows for fast graceful degradation in the case
  of component failure, i.e., automatic
  notification and removal from active use in the
  group does not teardown or restore faulty
  component LSP --.
• Observations
• LCAS does not play any role in establishing the
  component LSPs, only in whether they are actively
  used within the VCAT group.
• Not all VCAT-capable endpoints are LCAS-capable

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Aim of this Draft

• Illustrate the use of GMPLS in supporting
  VCAT/LCAS operation
• Exhaustive list of component signal configuration
  scenarios
• Explain how current routing/signaling mechanisms
  can be used to support VCAT/LCAS applications
• When existing mechanisms are insufficient, try to
  extend current work to cover whats missing

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Why not reuse existing sols?

• Cant we use concatenated labels?
• Can only work on the same path
• Is this bundling?
• Bundling doesnt allow the service to span
  multiple component links
• Can we use association id for VCAT group?
• Probably

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Thinking about the solution

• Routing
• Add 2 bits, one for vcat capability, one for lcas
  capability of a TE link
• Signaling
• We need to tell how big the group is (VCAT) or is
  going to be (LCAS)?
• May need to know in advance so we dont set up 60
  and choke at 61
• We need some VCAT group id, possibly use
  association id
• List of extra error codes we thought of
• Be able to refuse the 1st one
• Be able to refuse subsequent ones no more
• Alarm such as signal label mismatch (mapping
  scheme, e.g. GFP, LAPS) should also be
  communicated as an error code
• Inter-domain boundaries
• May need to terminate association at the boundary
  and restart a new one

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Next Steps

• Comments received from Huub van Helvoort
• Is this work of interest to the WG?
• The overall objective is to document and/or
  standardize the bits bytes that make VCAT/LCAS
  possible in a GMPLS environment
• Suggest to adopt as WG document if there is
  interest continue develop solution
• Ethernet-specific part to live in different
  (applicability) id