The MPLS WG Archive

[Sandeep Sharma <ssharma@mail.irislabs.com>]

I think the initial question was geared more towards signaling protocols
that need to come into play if a LSP is needed between routers in two ASs.
For example, can you progress an RSVP message between AS boundaries?

While modeling layered networks helps in the network management of these
networks, it does not help in real-time signaling problems in the network.

- Sandeep

Sandeep Sharma
  Iris Labs

> -----Original Message-----
> From: neil.2.harrison@bt.com [mailto:neil.2.harrison@bt.com]
> Sent: Monday, November 27, 2000 3:57 AM
> To: iokumus@mailbox.syr.edu; mpls@UU.NET
> Cc: andy.bd.reid@bt.com; mike.sexton@alcatel.co.uk
> Subject: RE: interdomain LSP setup 
> 
> 
> Taner....you are referring to the architectural concept of 'layered
> networks', which is one facet of the larger discipline of functional
> modelling of networks.  That is, a link connection of a 
> client trail (which
> is 1 hop in the client trail) = a server layer trail.  LSPs 
> create layered
> networks (of theoretically arbitrary nested depth), and it is 
> something the
> IETF are going to have to get to grips with if MPLS is going 
> to progress
> beyond an intra-domain 'IP accessory' and have any properly engineered
> future.  This does not seem well understood by many it seems, 
> and it has
> some very important consequences that cannot be 
> ignored....especially wrt
> the functionality that must be applied at trail termination 
> points and the
> server->client adaptation mappings.  Getting to grips with 
> these concepts is
> critical as one moves the focus from intra-domain to inter-domain.
> 
> You may have seen some mails from me in the past that gave 
> some warnings on
> the need for more architectural rigour in this area....such as:
> -	since client layer links = server layer trail terminations,
> addressing across nested layer networks cannot be congruent 
> (this is an
> important issue for the Optical Transport Network and its many
> clients....here the concept is generalised MPLS);