Subject: Re:

From: "John Wysocki" <[email-masked]>
Date: Tue, 24 Apr 2001 20:26:04 -0000

I have very high level generic MPLS TE questions to ask.  If you could help 
me on it, I'll appreciate very much.

1) It's my understanding LSPs are usually within an AS and not inter-AS.  Is 
this correct?
2) BGP-TE is really not well defined yet, right?
3) Is multicast well defined in MPLS?
4) Only GMPLS defineds bi-directional LSPs, but ISIS usu takes links as 
bi-directional but MPLS tunnel is not.  Does anyone know how to handle this 
situation?

Thanks.

_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com

---

From: David Charlap <[email-masked]>
Date: Wed, 25 Apr 2001 14:00:07 -0400

John Wysocki wrote:
> 
> I have very high level generic MPLS TE questions to ask.  If you
> could help me on it, I'll appreciate very much.
> 
> 1) It's my understanding LSPs are usually within an AS and not
>    inter-AS.  Is this correct?

This is how they will typically be used.

There are explicit-route subobjects in RSVP-TE and CR-LDP for specifying
AS numbers as hops along an LSP.

It is theoretically possible for a single LSP to cross AS boundaries. 
But in actual practice, you will probably not see much of this.  Mostly
for political, security and business reasons.

> 2) BGP-TE is really not well defined yet, right?

There are drafts in progress for this.

> 3) Is multicast well defined in MPLS?

There are drafts in progress for this.

> 4) Only GMPLS defineds bi-directional LSPs, but ISIS usu takes
>    links as bi-directional but MPLS tunnel is not.  Does anyone
>    know how to handle this situation?

I don't see what the problem is.  Knowing that a link is bidirectional
doesn't force you to signal bidirectional LSPs on it.  No more than it
would (somehow) force the existance of bidirectional traffic over a link
in a non-MPLS network.

-- David