From owner-freebsd-hackers Sat Jun 24 10:11:12 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id KAA16878 for hackers-outgoing; Sat, 24 Jun 1995 10:11:12 -0700 Received: from mail.htp.com (mail.htp.com [199.171.4.2]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id KAA16872 for ; Sat, 24 Jun 1995 10:11:09 -0700 Received: from et.htp.com (et.htp.com [199.171.4.228]) by mail.htp.com (8.6.5/8.6.5) with SMTP id NAA19368 for ; Sat, 24 Jun 1995 13:10:00 -0400 Date: Sat, 24 Jun 1995 13:10:00 -0400 Message-Id: <199506241710.NAA19368@mail.htp.com> X-Sender: dennis@mail.htp.com X-Mailer: Windows Eudora Version 2.0.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: freebsd-hackers@freebsd.org From: dennis@et.htp.com (dennis) Subject: Re: FreeBSD as a router Sender: hackers-owner@freebsd.org Precedence: bulk >> >> >> 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