MPLS-TP OAM Framework
draft-ietf-mpls-tp-oam-framework-07
editors:Dave Allan, Italo Busi,Ben Niven-Jenkins
Changes Since Anaheim
• We’ve rev’d the document twice• Processed the comments of two “last calls”
– Including liaisons from SG15• “Tightened Up” the document significantly
– Terminology Changes• PST SPME
– Terminology Clarifications• Too many to mention
– Concept clarifications• Up & down MEP, per node/per interface MIPs• Some implications of instantiating SPMEs
– Noting actual procedures are “out of scope”
Changes Since Anaheim-2
• Some changes of note– Uniform model of TTL copying allowed for
SPMEs• Implication being TTL will address SPME MIPs,
which can then only use of an “out of band” return path
– Operation of LKI and LKR significantly clarified
Fault Reporting
A D B C
S-PE S-PEP P
PW MEG
LSP MEG
MEPMEP
MEPMEP MIP MIP
MIP MIP
Server MEG
LSP AIS
C detects a failure on the B-C Link that affects the A-D LSP
MEP
LSP AIS
MEP
D detects loss of continuity on the A-D LSP that affects the PWs carried over the LSP
PW AIS
B detects a failure on the B-C Link that affects the A-D LSP
MEP
MEP
A detects loss of continuity on the A-D LSP that affects the PWs carried over the LSP
PW AIS
Lock Reporting
A D B C
S-PE S-PEP P
PW MEG
LSP MEG
MEPMEP
MEPMEP MIP MIP
MIP MIP
Server MEG
LSP LCK LSP LCK
PW AIS
MEP
A detects loss of continuity on the A-D LSP that affects the PWs carried over the LSP
PW AIS
The B-C Link is locked at B in both directions
MEP
D detects loss of continuity on the A-D LSP that affects the PWs carried over the LSP
Open Issues
• Practical limits of detecting “unexpected OAM encapsulation”, a.k.a. mis-connectivity defect– How far into heuristics do we want to mandate?
• Short pipe and uniform models for SPMEs– Decoupling the configuration of TTL and TC copying
is not actually mandated anywhere
• Description of SPME MEGs– Can be any two points before SPME is setup
• Providing SPME does not “overlap” other SPMEs
– These two points become "adjacent" at the LSP sub-layer after the SPME is setup
Next Steps
• The document is quite close to a “last” last call– Third time lucky?
• We’ll look to resolve the last few outstanding issues and request a last call before Beijing