Jay Karthik, Cisco Systems

1
LDP Data Plane Convergence Benchmarking

• Jay Karthik, Cisco Systems
• Rajiv Papneja, Isocore
• Thomas Eriksson, TeliaSonera
• Mohan Nanduri, VSNL International

70th IETF Meeting
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Motivation (1)

• MPLS working group as a result of industry wide
  survey published
• RFCs 5037 and 5038
• Experience with the Label Distribution Protocol
  (LDP) (RFC 5037)
• The Label Distribution Protocol (LDP)
  Implementation Survey Results (RFC 5038)
• Obtained results were categorized into 3 classes-
• Configuration Issues,
• Vendor bugs,
• Protocol issues
• Protocol issues are tied to syncronization
  between LDP and IGP resulting in
• Slow convergence
• Traffic blackholing
• Taking up LDP work item following the completion
  of IGP work
• LDP convergence benchmarking to be considered
  following IGP
• The time is right and we would like to generate
  more interest on the topic in the WG

3
Motivation (2)

• Considering the number of revenue generating
  services riding on LDP today (L2/L3 Services)
• Operators would like to have tight convergence
  numbers for LDP
• Operators should be able to verify the traffic
  loss time in their networks for different
  scenarios (similar to IGP convergence)
• No common benchmarking terminology/ methodology
  exist in the industry for LDP
• Uniform convergence benchmarking methodology
  required when verifying different implementations
• Important to both vendor and SP community

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Current status

• draft-eriksson-ldp-convergence-term-04.txt
• Added new term LDP Advertisement Type
• Author list updated
• Currently expired
• draft-karthik-bmwg-ldp-convergence-meth-01.txt
• Updated the draft based on the comments received
  from the list
• Several comments received, including one from Bob
  Thomas, LDP spec author. Thanks for his input!
• Updates to ver-00
• Added new convergence events (Peer status changes
  including peer coming up or going down)
• Default LDP Timer value recommendations
• Updated Procedures
• Currently working on formal work item proposal to
  the working group
• Plan to submit it soon in the hopes to generate
  discussion on the topic and have more people
  review the work

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Next steps

• We seek
• Input from Service Providers in the BMWG group
• Input from test vendors on the procedures
• We request
• The BMWGers to review the draft and provide
  feedback and contribute to this effort
• The WG to support this item to be accepted as a
  work group item
• Comments?

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Backup
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Snippet from RFC 5037

• Experience with the Label Distribution Protocol
  (LDP)
• ltsnipgt
• 1. Configuration issues. ltsnipgt
• 2. Vendor bugs. ltsnipgt
• 3. Protocol issues. - The synchronization
  required between LDP and the IGP was listed as
  the main protocol issue. Two issues were
  reported 1) slow convergence, due to the fact
  that LDP convergence time is tied to the IGP
  convergence time, and 2) traffic blackholing on a
  link-up event. When an interface comes up, the
  LDP session may come up slower than the IGP
  session. This results in dropping MPLS traffic
  for a link- up event (not a failure but a
  restoration). This issue is described in more
  detail in LDP-SYNC. ltsnipgt