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Re: Equal-cost path



On Apr 13, 2005, at 7:38 AM, Naidu, Venkata wrote:

 If we assuming all nodes in an area have same
 capabilities (like, line rate forwarding etc), fewer number
 node path performs better in the average case.


I do not believe that you can make this claim, except in a simulation, which has little to do with reality.


In real networks, with reasonably fast routers and links, the performance of the routers and per-link serialization are greatly overwhelmed by other issues (such as the speed of light and queue lengths.)

One could just as plausibly posit that, on average, a random assignment in the case of equal path costs could improve performance by spreading the load more effectively across the infrastructure, but it totally depends on the particulars of equipment, topology, and traffic.

A case could also be made that well-engineered networks ought not to have equal cost paths by accident; most of the time they should only appear if the network engineers wanted to take advantage of path splitting.

In any case, a router that did not support equal cost multipath would be so broken that nobody would buy it, making the whole question academic.

--Dave