First of all, a multicommodity flow problem is not NP-complete provided that the individual flows are an order of magnitude or so smaller than the link capacities so that you can use a fluid approximation. Moreover, you can come up with a heuristic that works pretty well. I believe you must have heard of greedy algorithms. It is **so** easy to label a problem NP complete these days. Bora -----Original Message----- From: Andrew Bender [mailto:abender@tns-inc.com] Sent: Friday, October 22, 1999 2:01 PM To: nanog@merit.edu Subject: RE: Traffic engineering tools

Date: Thu, 21 Oct 1999 20:49:07 -0700 From: Bora Akyol <akyol@pluris.com> Subject: RE: Traffic engineering tools

If you don't want a GUI and the fancy what if scenarios, it is not difficult to write a Perl/Script that does constraint-based routing or Multi-commodity flow problems.

I would guess 2-3 weeks if one is familiar with basic linear programming.

Bora

Release note: NPcomplete.pl may also require 2-3 weeks to converge when sub{optimum_backup_paths} is used. This may be due to a suspected "suboptimality" in PDL::Opt::Simplex... Application note: "basic" as the term is used in the context of the phrase "basic linear programming" seen in the marketing literature should be taken to mean "graph or subgraph of degree 1" Regards, Andrew Bender Total Network Solutions, Inc. P.S. Advance apologies for the (ostensibly excusable?) off topic cynicism...