[25610] in North American Network Operators' Group
RE: Traffic engineering tools
daemon@ATHENA.MIT.EDU (Bora Akyol)
Fri Oct 22 18:04:03 1999
Message-ID: <6342F12F9359D311990B009027A1B9B603E6E7@monterey.pluris.com>
From: Bora Akyol <akyol@pluris.com>
To: "'Andrew Bender'" <abender@tns-inc.com>, nanog@merit.edu
Date: Fri, 22 Oct 1999 15:02:24 -0700
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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...
