All the responses have been really helpful. Thanks to everyone for being friendly and for taking the time to answer in detail. I've asked a hardware provider to quote for a couple of x86 boxes and I'll look for suitable Intel NICs too.
Jim: We're a very small ISP and have a full mix of packet sizes on the network but the vast majority is outbound on port 80 so hopefully that'll help. Any more input will of course be considered. I may post the NIC models for approval if I'm scratching my head again :) Thanks, Chris 2008/12/17 Jim Shankland <na...@shankland.org> > Chris wrote: > >> Hi All, >> Sorry if this is a repeat topic. I've done a fair bit of trawling but >> can't >> find anything concrete to base decisions on. >> >> I'm hoping someone can offer some advice on suitable hardware and kernel >> tweaks for using Linux as a router running bgpd via Quagga. We do this at >> the moment and our box manages under the 100Mbps level very effectively. >> Over the next year however we expect to push about 250Mbps outbound >> traffic >> with very little inbound (50Mbps simultaneously) and I'm seeing differing >> suggestions of what to do in order to move up to the 1Gbps level. >> > > As somebody else said, it's more pps than bits you need to worry about. > The Intel NICs can do a full gigabit without any difficulty, if packet > size is large enough. But they buckle somewhere around 300Kpps. 300K > 100-byte packets is only 240 Mb/s. On the other hand, you mentioned > your traffic is mostly outbound, which makes me think you might be a > content provider. In that case, you'll know what your average packet > size is -- and it should be a lot bigger than 100 bytes. For that type > of traffic, using a Linux router up to, say, 1.5-2 Gb/s is pretty trivial. > You can do more than that, too, but have to start getting a lot more > careful > about hardware selection, tuning, etc. > > The other issue is the number of concurrent flows. The actual route > table size is unimportant -- it's the size of the route cache that > matters. Unfortunately, I have no figures here. But I did once > convert a router from limited routes (quagga, 10K routes) to full routes > (I think about 200K routes at the time), with absolutely no measurable > impact. There were only a few thousand concurrent flows, and that > number did not change -- and that's the one that might have made a > difference. > > I hope this is helpful. > > Jim >
