The MPLS-OPS Archive

Cell Relay Retreat>MPLS-OPS Archive>month:2004-May> msg00032



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

RE: Reasons to deploy MPLS-TE

  • From: sthaug@nethelp.no
  • Date: Thu, 06 May 2004 21:46:04 +0200
  • Cc: mpls-ops@mplsrc.com
  • Resent-Date: Thu, 6 May 2004 16:15:14 -0400
  • To: puddinghead_wilson007@yahoo.co.uk

> I agree BGP forwards only 1 route, yet how would you say FRR is slower?

I would not. I would expect that in most cases FRR would be slightly
faster than a well-tuned IGP, which again would be faster than BGP.

> take this case of how it wokrs in LDP/OSPF
> 1. we wait for an LSP to down to be detected
> 2. we then use new LSP after detection and using the protocol's database to see alternate route to node after receiving the "tigger".
>  
> Incase of BGP it would be:
> 1. VPNv4 route withdrawn, and hence the BGP update propgates a new route immediately after running decision making alogirhtm (implicit withdraw et al )
> 2. this amounts to *almost* the same propogation delay as case 1 above...does it not?

Not in my experience. YMMV.

Steinar Haug, Nethelp consulting, sthaug@nethelp.no

>  
> 
> 
> sthaug@nethelp.no wrote:
> > If *FRR* is the biggest driver of TE, then that can be achieved by
> > using BGP as an LDP also :) (or using any other LDP) as they would
> > give us multiple LSPs to the same VPNv4 prefix :)?? Will they not?
> 
> The point of FRR, as I understand it, is mainly to let you reroute to
> a predefined path in the seconds before your normal IGP converges to
> a new path. I don't see how BGP can help you there - remember a BGP
> speaker will only announce *one* best path to other BGP speakers.
> 
> Steinar Haug, Nethelp consulting, sthaug@nethelp.no
> 		
> ---------------------------------
>   Yahoo! Messenger - Communicate instantly..."Ping" your friends today! Download Messenger Now

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