The MPLS-OPS Archive

Cell Relay Retreat>MPLS-OPS Archive>month:2002-May> msg00164



[Date Prev][Date Next][Thread Prev][Thread Next]  
  [Date Index][Thread Index][Author Index][Subject Index]

Re: AS Border Router

  • From: Robert Raszuk <raszuk@cisco.com>
  • Date: Tue, 21 May 2002 17:39:05 +0200
  • CC: Umit.Inan@alcatel.com.tr, rajiva@cisco.com, asimha@cisco.com, mpls-ops@mplsrc.com
  • Organization: Signature: http://www.employees.org/~raszuk/sig/
  • Resent-Date: Tue, 21 May 2002 12:50:19 -0400
  • To: Christopher Poh <tvpoh@essex.ac.uk>


The only comment I would add here is that the performance wise with ASIC
or NPs IP address lookup is very similar in speed to mpls label lookup
(the latter could be anywhere from 5-15% faster). Said this there is no
much of a gain here. Now you said IP packet processing ... I hope by
this you just mean lookup otherwise for packet's with options that would
not be valid switching comparison.

R.

> Christopher Poh wrote:
> 
> Robert,
> 
> >> >What LSP you have in mind ? LDP or TE ? If TE as long as those dst are
> >> >reachable sure no problem. As far as LDP yes the same. After all you can
> >> >label the default route as well :). Redistributing but only specifics
> >> >could be yet another way but I am not sure what application such a LSP
> >> >would be used for.
> >>
> >> If it were to distribute only specific routes, is it true that the LSPs are naturally established through control driven triggered by IGP routing protocol.
> >
> >Yes and I think that would be a way to do it ... but again I am still
> >missing the bigger picture here on the overall application.
> 
> Firstly, sorry to keep this thread long. Hope it doesn't annoy anyone. Here is the bigger picture of my question. I am interested in knowing how much we can
> avoid L3 processing when delivering packets from a source to destination(s). Since the Internet is built-up from a number of domains, there will be many (actual)
> routes that are missing from the view of a router in a domain. Due to this, all packets destined to certain exterior destinations will end up at the route aggregator
> point, which is most probably an AS border router, where L3 processing needs to be done to perform further labelling to packets. This would add heavy IP
> address lookup processing to an already loaded AS border router. Having said that, I am wondering whether we can allow an AS border router seletively
> advertises its LSPs for active routes to leverage the L3 processing.
> 
> Any comments?
> 
> -Chris.

-------
The MPLS-OPS Mailing List
Subscribe/Unsubscribe:  http://www.mplsrc.com/mplsops.shtml
Archive: http://www.mplsrc.com/mpls-ops_archive.shtml