From owner-freebsd-hackers Thu Jun 22 18:08:34 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id SAA09667 for hackers-outgoing; Thu, 22 Jun 1995 18:08:34 -0700 Received: from gndrsh.aac.dev.com (gndrsh.aac.dev.com [198.145.92.241]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id SAA09656 ; Thu, 22 Jun 1995 18:08:31 -0700 Received: (from rgrimes@localhost) by gndrsh.aac.dev.com (8.6.11/8.6.9) id SAA09137; Thu, 22 Jun 1995 18:08:10 -0700 From: "Rodney W. Grimes" Message-Id: <199506230108.SAA09137@gndrsh.aac.dev.com> Subject: Re: FreeBSD as a router To: tom@uniserve.com (Tom Samplonius) Date: Thu, 22 Jun 1995 18:08:10 -0700 (PDT) Cc: jkh@freebsd.org, evanc@synapse.net, hackers@freefall.cdrom.com In-Reply-To: from "Tom Samplonius" at Jun 22, 95 05:42:08 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 938 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. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation Company Reliable computers for FreeBSD