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RE: [RPRWG] TDM or ATM/FR service emulation over RPR ring




Hi Yu,
RPR Standard defines a MAC and does not deal directly with how to transport
the services. It provides Classes of Service that can be used to transport
different services, but these classes are defined based on their
characteristics (delay, delay variation,..) and not on the type of service.

As for the specific way of transporting TDM/FR/ATM over packet networks I
recommend you to look in the IETF PWE3 work.

And yes, we have considered the stringent timing requirements of TDM over
RPR (you can see some presentations of simulations results as early as March
2001). From the results, and also theoretical calculations, for high rate
ring there is no problem to deal with the delay variation using a small
dejitter buffer at the receiver.

Leon Bruckman
VP & Chief System Architect
Corrigent Systems

-----Original Message-----
From: Yu Ning [mailto:yuning@xxxxxxxxxxxxxxx]
Sent: Tuesday, March 05, 2002 10:12 AM
To: stds-802-17@xxxxxxxx
Subject: [RPRWG] TDM or ATM/FR service emulation over RPR ring



Hi All,

Apologize if this question been asked before (pls give a pointer to former
answer then.)

How is the TDM, ATM/FR service emulation provided through RPR ring ?
Is this emulation based on a protocol translation scenario (protocol field
mapping), or raw encapsulation scenario (put TDM/ATM/FR frame as RPR
payload)?

Because I saw some product brochure from vendors, like Luminous, Riverstone,
their MAN box has both Ethernet interface and PDH interface, like E1/T1, and
all through RPR backhaul (said so). It just puzzled me how to emulate these
service through RPR ring.

I've checked RPR whitepaper, and rfc2892, there is no description on
service emulation issue, only a natural L3 IP into RPR frame illustration.

If TDM via RPR ring, anyone considered the stringent timing requirement
from TDM ?


thanks for any input.


Yu Ning

______________________________________

(Mr.) Yu Ning, Chief Engineer
ChinaNET (AS4134) Senior Support
Internet Dep. DCBU, China Telecom
Beijing, P.R.China +86-10-62072357
Personal Page-> http://navidog.126.com
______________________________________