Re: Is the advertisement (IGP) of available BW at each pre-emptionle vel is a DS-TE- requirement ?

[Jim Boyle <jboyle@pdnets.com>]

On Fri, 9 Nov 2001, Choudhury, Sanjaya wrote:

>
> 	Hi! I have few questions related to the LSP pre-emption in a DS-TE
> 	environment. I will appreciate, your help with these questions.
>
> 	Q1. If we support pre-emption _across_ different DiffServ classes,
> 	then what is the advantage in advertising available bandwidth for
> each
> 	class at _each pre-emption level_ ?

There is no agreed upon protocol proposal for DS-TE right now, preemption
within and across class types is an issue that has been raised on the
list.  At this point, the requirements document is under a revision which
should clarify the need (or lack of need) for this, the revision is
expected in the next week (or so).  Francois or one of his co-authors
may answer your question more directly, as you are refering to their
proposal.

>
> 	Q2. In general, does the advertisement of available of bandwidth
> 	at each pre-emption priority level, help in building/managing a
> 	TE network ?

Yes.

>
> 	[Considering that at time t1 , there is might be enough BW for
> 	class-x/priority-3, however at time t1+2min another LSP with
> 	priority-2 might preempt the previous LSP.]
>
> 	Q3. In a DiffServ TE domain, where the network administrator
> 	initiates the creation the TE tunnels (using MPLS-TE-MIB ),
> 	when/how can he take advantage of the following pre-emption
> 	scheme:
> 		a) Preemption within the same DiffServ traffic class
> 		b) Preemption across different DiffServ traffic classes

I'm not sure how people use the MPLS-TE-MIB to setup TE tunnels, so I
can't help you there.  I think you mean class-type above, so again, that
is a specific proposal.

>
> 	Thanks,
> 	sanjay
>
>