Subject: draft-ietf-mpls-diff-ext-07.txt

From: Francis Arts <[email-masked]>
Date: Sat, 25 Nov 2000 10:30:16 +0100

Hello,

I have a question concerning the draft-ietf-mpls-diff-ext-07.txt draft.

Section 2.6.2, p.13 of this draft states the following:

"The Pipe Model is particularly appropriate to environments in which
the incoming interface of the LSP Ingress and the outgoing interface
of the LSP Egress are in Diff-Serv domains which use a common set of
Diff-Serv service provisioning policies and PHB definitions, while
the LSP spans one (or more) Diff-Serv domain(s) which use(s) a
different set of Diff-Serv service provisioning policies and PHB
definitions."

This statement could be interpreted in 2 ways. Which one is correct:

1) The 2 diff serv domains connected by the LSP use the same PHBs but
may use a different DSCP encoding of the PHB. If a different DSCP
encoding is used, a translation needs to be done at either end.

2) The 2 diff serv domains connected by the LSP use the same PHBs and
the same
DSCP encoding of the PHB.

Thanks for your answer.

Kind regards,

    Francis.

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From: Francois Le Faucheur <[email-masked]>
Date: Tue, 28 Nov 2000 16:19:10 +0100

Francis,
The targetted scenario is 2) [ two sub-clouds of a single Diff-Serv domain
interconnected through an MPLS cloud ]. But I think you could make it work
for 1) assuming, as you said, that you do the right DSCP translation.
Francois