STPP Simple TDM Pseudowire Protocol PWE3 – 57th IETF 16 July 2003 Yaakov (J) Stein

The Great TDM Battle draft-anavi-tdmoip-00 was prepared for 50th IETF comparisons presented at 52nd IETF we have been discussing for > 2 years several compromises reached and rejected … the time has come for a decision 50 Minneapolis 51 London 52 Salt Lake City 53 Minneapolis 54 Yokohama 55 Atlanta 56 San Francisco 57 Vienna

draft-anavi-tdmoip-05 Multiple main modes to optimize for special cases raw (STPP) AAL1 unstructured, structured, structured w/ CAS AAL2 HDLC Various special mechanisms to cope with network defects adaptive clock recovery common clock SRTS packet loss avoidance packet loss concealment Simple interworking with existing AAL1 and AAL2 networks

draft-vainshtein-cesopsn-06 Evolved into a long complex draft Single main mode with plethora of submodes framelength locking OR frame locking full multiframe in packet OR multiframe marking RTP OR RTP compressed OR RTP suppressed T1 octet-aligned OR 8-consectuive frames optional “ECMP Prevention” protector signaling packets OR in-packet signaling structure Support (for which submodes?)

STPP Simple (dumb) TDM pseudowire protocol Draft is only 11 pages, readable by non-TDMers Designed to cover most common TDM cases clock available or unimportant low packet loss TDM structure unimportant CAS/CCS signaling unimportant Simply encapsulate arbitrary length TDM packets When special sizes are needed, their use is encouraged default sizes are those needed by CESoPSN implementations should use sizes that simplify AAL1-interworking if needed No special payload treatment (e.g. AAL1 buffering or frame-locking) Highest possible BW efficiency (no extraneous overhead)

Proposal Accept STPP for most common (simplest) TDM cases broad support easy to implement Accept both TDMoIP and CESoPSN for special cases structure critical CAS signaling high packet loss problematic clock recovery interworking with existing networks and let the market decide