The MPLS WG Archive

[Atsushi Iwata <iwata@ccm.CL.nec.co.jp>]

Hi, all

The draft that peter mentioned is our following draft.

draft-fujita-ospf-te-summary-00.txt

This approach assumes a hierarchical QoS path computation that PNNI routing 
protocol does in the ATM world.

I would like to get any opinion or any suggestions (Pros and Cons) on this 
approach.

Regards,

At 08:36 00/03/29 -0500, Peter Ashwood-Smith wrote:

>Currently the MPLS working group has not addressed this subject in any 
>depth although there was a draft presented in the routing area group today 
>in Adelaide that started to talk about solutions.
>
>As far as I know there are basically two ways to attack this problem, or 
>at least two general flavors.
>
>piecewise source routing. In this approach you compute a gateway based on 
>the destination address and then do normal flat source routing to that 
>gateway. Go through the gateway and repeat. In other words you are doing 
>piecewise traffic engineering but letting the exterior gateway protocols 
>figure out which gateway you should be going to next. Obviously there are 
>problems with this approach since it puts everything though the same 
>gateway. I actually helped built a piecewise solution like this a while 
>ago. It has some good advantages in that local (at least local to an AS) 
>repair is natural to do as are local modification etc.
>
>hierarchical source routing. This is what ATM does, you compute a hop list 
>hierarchically against a hierarchical topology database etc. etc. I'm not 
>sure this approach is appropriate for the Internet due to the massive size 
>of the problem but I'm really not an ATM hierarchical routing guy.
>
>I would hope that the MPLS working group or the Traffic Engineering 
>working group can start looking at these issues, possibly with some 
>simulations of the different approaches against a set of real AS 
>topologies. Some of the PNNI architects and BGP architects are active 
>members  of the MPLS working group so you can be sure that it will cause 
>some heated debate ... should be extremely interesting and challenging.
>
>Cheers,
>
>Peter
>
>-----Original Message-----  From:   Andrzej Czerczak 
>[SMTP:Andrzej_Czerczak/HeadQ@netia.pl]  Sent:   Tuesday, March 28, 2000 
>6:04 AM  To:     mpls@UU.NET  Subject:        MPLS routing accross AS 
>boundaries
>
>Hi,   Where can I get information on the subject of MPLS QoS routing 
>accross  Autonomous System boundaries?
>
>Thanks  Andrzej

----------------------------------------------------------------
Atsushi Iwata
Assistant Manager
Network System TG, C&C Media Research Labs, NEC Corporation
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