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RE: Another question on draft-ietf-tewg-diff-te-proto-01.txt

At 09:09 09/07/2002 -0400, David Allan wrote:



I'm not spotting the difference between what you are saying and what I am
saying....only potential correction to my statement is that I should have
been more precise and said '"can" carry multiple class types.'
that's the point.
It is a significant differenece in the context of DS-TE since one major deployment option for DS-TE is precisely to use E-LSPs each transporting traffic from a single Diff-SErv class.

Cheers

Francois


rgds
Dave

 -----Original Message-----
From: Francois Le Faucheur [mailto:flefauch@cisco.com]
Sent: Tuesday, July 09, 2002 4:49 AM
To: Allan, David [CAR:NS00:EXCH]
Cc: Nabil Seddigh; te-wg@ops.ietf.org
Subject: RE: Another question on draft-ietf-tewg-diff-te-proto-01.txt


Dave,

At 13:24 08/07/2002 -0400, David Allan wrote:


You mean to support the engineering of individual class types in an E-LSP?
An E-LSP by definition carries mulitple class types....


Not quite.
By definition and E-LSP is CAPABLE of carrying traffic from multiple Traffic
Aggregate. But it is perfectly fine to transport traffic from differnet
Traffic Aggregates on differnet E-LSPs (i.e. one Traffic Aggregate per
E-LSP).

When you do not do DS-TE, you woudl generally transport multiple Traffic
Aggregates over E-LSPs.

When you do DS-TE you would either:
        - use L-LSPs
        - use E-LSPs with traffic from a single Traffic Aggregate
        - use E-LSPs with traffic from multiple Traffic Aggregates BUT you
then have a few constraints (see REQTS draft) such as not being able to
perform separate Constraint Based Routing of each TA on  a given E-LSP.


Cheers

Francois


cheers
Dave

> -----Original Message-----
> From: Nabil Seddigh [mailto:nseddigh@tropicnetworks.com]
> Sent: Monday, July 08, 2002 12:29 PM
> To: Allan, David [CAR:NS00:EXCH]
> Cc: te-wg@ops.ietf.org
> Subject: Re: Another question on draft-ietf-tewg-diff-te-proto-01.txt
>
>
>
> Dave,
>
> Mechanisms to support multiple class types on an E-LSP were proposed
> in this WG. Some providers and vendors expressed interest in
> such schemes. However, in Utah, the WG felt that standardizing
> multiple OA-ELSP would be premature until the basic DS-TE
> mechanisms are standardized and shown to be viably deployable.
>
> Updated versions of the related drafts can be found below:
>
> http://www.ietf.org/internet-drafts/draft-ganti-tewg-diffserv-
> multicos-elspreq-00.txt
> http://www.ietf.org/internet-drafts/draft-ganti-mpls-diffserv-
> elsp-02.txt
>
> Best,
> Nabil Seddigh
>
>
>
> > This implies a 1:1 relationship between TTs and LSPs, this wouldn't
> > necessarily be true for an E-LSP. Now the mechanisms don't
> currently exist
> > to support associating multiple class types/bandwidth
> constraints for an
> > E-LSP, but if traffic trunk is exclusively an L-LSP
> concept, couldn't we pin
> > this down a bit more explicitly..?
> >
> > thanks
> > Dave
>