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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: What is the limit? (was RE: multi-homing fixes)
On Wed, 29 Aug 2001, Sean M. Doran wrote: > | I think there is real promise in SMP though. There are many SMP > | applications that scale near linearly, and I think properly designed > | routing can be one of them. If a linear SMP solution can be found > | then there is at least one way to scale the routing infrastructure > | to near infinate size simply for $$$'s. > > So like I have to hop on a plane, but the Russian guy wakes up > really soon, and this is very much his field... :-) > > You won't like the answers though, 'cause they're consistent > with mine. Oh well. Hmm. Actually, routing info processing parallelizes fairly well. Computationally heavy things like policy evaluations and BGP protocol engines are generally done on per-peer basis, so you can do it on a bunch of processors in parallel; the path comparison (aka best route selection) is done on per-prefix basis (i.e. the best path for each prefix is generally independent from all other prefixes) - so it can be segmented by address blocks (i.e. one processor does path selection for 0/2, the second for 1/2, the third for 2/2, the fourth for 3/2; etc; you got the idea :) That said, implementing heavily parallel routing software in practice is quite hard. Even non-parallelized routing code is not easy to do right, as was convincingly demonstrated by OFRV. The approach I advocated when starting Pluris was to dramatically reduce topological complexity of networks instead by having only one large (internally redundant) IP router per POP instead of clusters of smallish boxes. I still think this is the best approach, because it improves not only exterior routing performance (smaller iBGP meshes) but also interior routing. Like, Keep It Simple :) --vadim
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