North American Network Operators Group
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Re: virtual aggregation in IETF

  • From: Adrian Chadd
  • Date: Sun Jul 20 12:51:00 2008 
On Sun, Jul 20, 2008, Joel Jaeggli wrote:

> Not saying that they couldn't benefit from it, however on one hand we 
> have a device with a 36Mbit cam on the other, one with 2GB of ram, which 
> one fills up first?

Well, the actual data point you should look at is "160k odd FIB from a couple
years ago can fit in under 2 megabytes of memory."

The random fetch time for dynamic RAM is pretty shocking compared to L2
cache access time, and you probably want to arrange your FIB to play well with
your cache.

Its nice that the higher end CPUs have megabytes and megabytes of L2 cache
but placing a high-end Xeon on each of your interface processors is probably
asking a lot. So there's still room for optimising for sensibly-specced
hardware.

Of course, -my- applied CPU-cache clue comes from the act of parsing HTTP requests/
replies, not from building FIBs. I'm just going off the papers I've read on the
subject. :)



Adrian