For IGP metrics, I use a formula that goes like this: m=d*(l/s)+l+10 Where m is the metric, d is the distance between the endpoints, l is the latency, and s is the link speed (in Mbps) Works well for us -- William R. Charnock Director Core Technology Allegiance Telecom, Inc. 469.259.2260 (V) 469.259.9079 (F) ----- Original Message ----- From: "Joel Krauska" <jkrauska@gte.net> To: <nanog@merit.edu> Sent: Thursday, January 10, 2002 11:49 PM Subject: Intelligent IGP Link Costing Algorithms?
Does anyone use intelligent algorithms for determining IGP costs?
It's a widely academic topic on solving a NP-Hard problem, but I've found most providers tend to stick to simple functions based on RTT and link capacity.
With bandwidth costs becoming more and more reasonable, it also seems to have been a simple "get bigger pipes" between point A and B solution.
However, with budgets being tighter, I would assume some more thought has been put in to using more intelligent methods of traffic optimization. (briefly ignoring the MPLS TE "solution")
An added twist appears to be that a full demand matrix is difficult to build without large systems of flow collection. I'm curious if the problem can easily be approached without full insight in to this data. (per link usage yes, but without end-to-end flows)
I've seen a few modeling applications, but nothing that attempts to solve the general optimization problem.
Thoughts? Is there a need for something like this? Are there existing effective solutions?
Thanks,
Joel Krauska