RE: Virtual concatenation: a clarification on sequence numbers

["Bernstein, Greg" <GregB@ciena.com>]

Hi Gopi, I'm not sure if this is the right place to ask the question. So let
me ask you a question back.  Are you talking about (1) the "internal"
sequence number that virtual concatenation uses to keep track of the
relative positions of the payloads?  Or (2) the time slot numbering of the
"component signals" in a virtually concatenated group?

(1) Is done in the hardware of a Path Termination Chip that originates the
Virtual concatenated group.  And hence not really a question for this forum.

(2) Indicating the timeslots used (to the other end) can be done with a
signaling protocol such as RSVP-TE.  The exact method for indicating which
signals are components of which virtual concatenation groups, hopefully is
explained in the new SDH/SONET extensions draft.

Greg B.
-----Original Message-----
From: gopi@india.tejasnetworks.com [mailto:gopi@india.tejasnetworks.com]
Sent: Wednesday, November 06, 2002 5:58 AM
To: ccamp@ops.ietf.org
Cc: sjtrowbridge@lucent.com; Bernstein, Greg; Anup@jasminenetworks.com;
mvissers@lucent.com
Subject: Virtual concatenation: a clarification on sequence numbers


hi..

I was going through the thread
        http://ops.ietf.org/lists/ccamp/ccamp.2001/threads.html#00295
        subject: "concatenation extensions in sonet/sdh"

I needed a small clarification on virtual concatenation sequencing

Sequence number is sent by the transmitter and receiver checks for
the sequence number to perform interleaving.

  IS this sequence number "Provisioned"(on both terminating equipments) ?
   OR
  Is it automatically assigned by the transmitting equipment in some
  sequence and the receiver synchronizes with the transmitters sequence
number?


I read the following relevant standards on virtual concatenation, but
couldn't
clearly understand how the receiver knows the sequencing of the
individual links.
+ T1X1.5/2001-062(Synchronous Optical Network (SONET) - Basic
    Description including Multiplex Structure, Rates and Formats,
    put up on ftp.t1.org/..../1X150620.DOC)
+ G.707, G.783(virtual concatenation)
+ G.7042(LCAS)

Thanx in advance
Gopi