Yaakov (J) Stein

STPP S

imple

T

DM

P

seudowire

P

rotocol

PWE3 – 57 th IETF 16 July 2003 STPP Slide 1

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

STPP Slide 2

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 STPP Slide 3

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 RTP OR multiframe marking RTP compressed OR RTP suppressed T1 octet-aligned OR optional 8-consectuive frames “ECMP Prevention” protector signaling packets OR in-packet signaling structure 

Support

(for which submodes?)

STPP Slide 4

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)

STPP Slide 5

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

STPP Slide 6