Date: Sat, 24 Jun 1995 13:10:00 -0400 From: dennis@et.htp.com (dennis) To: freebsd-hackers@freebsd.org Subject: Re: FreeBSD as a router Message-ID: <199506241710.NAA19368@mail.htp.com>
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>> >> >> On Thu, 22 Jun 1995, Jordan K. Hubbard wrote: >> >> > That said, be aware that any kind of UN*X box doesn't exactly compete >> > with a Cisco in terms of performance. They throw raw hardware at the >> > problem whereas we have to do it the hard way, in software. >> >> The bottleneck certainly can't be in the CPU can it? Where is the >> bottleneck with PCI and a good 486 motherboard? > >The bottleneck is that you have to wait for full frame reception >before you get an interrupt to tell you to go look at the header >to decide what to do with the packet. > >In dedicated router hardware they use the trick of interrupting >the CPU after N bytes have been recieved (N is programmable) so >they can actually decide what to do with the packet before it is >even completly received. > > This is not necessary to get good throughput, although it wouldn't hurt. You can still get 5mbs without this, which is plenty. dennis
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