From owner-freebsd-isp Sun May 26 12:43:36 1996 Return-Path: owner-isp Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id MAA11367 for isp-outgoing; Sun, 26 May 1996 12:43:36 -0700 (PDT) Received: from cesium.clock.org (cesium.clock.org [17.255.4.43]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id MAA11359; Sun, 26 May 1996 12:43:33 -0700 (PDT) Received: by cesium.clock.org id <119170-29765>; Sun, 26 May 1996 12:43:23 -0800 From: Sean Doran To: dennis@etinc.com (Dennis) CC: jkh@time.cdrom.com, hackers@freebsd.org, freebsd-isp@freebsd.org, smd@cesium.clock.org In-reply-to: dennis@etinc.com's message of Fri, 24 May 1996 14:06:49 -0400 Subject: Re: The view from here (was Re: ISDN Compression Load on CPU) References: <199605241806.OAA01368@etinc.com> Message-Id: <96May26.124323pdt.119170-29765+19@cesium.clock.org> Date: Sun, 26 May 1996 12:43:18 -0800 Sender: owner-isp@freebsd.org X-Loop: FreeBSD.org Precedence: bulk -----BEGIN PGP SIGNED MESSAGE----- >>>>> "Dennis" == Dennis writes: Dennis> All of the routers on the market are just Dennis> basically PCs, in one form or another. Cisco Dennis> OS is just a hacked up unix os, so what your Dennis> really saying is that the guys at cisco write Dennis> better code than you do. Well, your inaccuracies need correcting. Firstly, "IOS" (a name I hate) is not like UNIX in just about any respect you'd care to think about. In particular, there is no preemptive scheduling, processes are free to walk all over each other's memory, there is a very weak distinction between user space and kernel space (in particular, a crash in a process will usually take the whole system out), and there is no facility for adding in processes which are not linked at compile time. IOS is, pretty simply, a very specialized single program controlling a hardware system. That it happens to multitask internally doesn't really change this. The easiest comparison between IOS and another OS would probably have to do with TOPS-20, but that's largely because of the interface that human users see. The value of IOS is, IMO, essentially equal to the value of the people coding. Dave Katz, Ravi Chandra, Paul Traina (who plays with FreeBSD, I note), Greg Christy, the late Tony Li and a number of others are certainly much better at coding things having to do with such esoterica as IS:IS, BGP4 and flinging IPv4 packets around too quickly than anyone else I know anywhere. I'm not sure I'd trust them to play with "a hacked up unix os", or certain other guts in IOS, but that is not what they do. Conversely, what they do is not what anyone else on this list does unless he also works for Cisco or its competitors including 3Com, Bad Notworks or the gated consortium (and even then, gated people do not generally play with anything more than the routing protocols and getting routing information propagated into the kernel). "All of the routers on the market are just basically PCs" is, I hope, rhetorical licence, as it's pretty obviously untrue. No high end router I can think of except perhaps the current generation of Cisco 7500s (one RSP, no smart interface cards) is very much like a PC at all. On the low end, you're right, though, except you have to get to the very low end before you get to "routers" that _really_ are PCs, without more than a tiny amount of specialized hardware goo. (I think of Netblazers here). There are definite and obvious advantages to being able to use a UNIX-using PC (or Sun SPARC) as a low-to- moderate-end router. Making up stories about Cisco products in particular is not necessary to prove that point, and it doesn't really detract from the obvious disadvantages of using a PC instead of a dedicated router, both technical and non-technical. Sean. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 Comment: PGP Public Key in ftp://ftp.sprintlink.net/engineer/smd/pgpkey iQCVAwUBMai0JESWYarrFs6xAQExjQP+MpvJhFgD2A+NIjk0eYJspkiR6+rmL4x0 z6L9wP85PKnNHniPZHR/RpiQFzT//fx0TlcuOiZuN9ZNSquWro3NjLmehSJOjOgi Ui8jijzjnU53d18iGuWx6AbkDqZk5D3QQoH8ImEpIpAUImT6irq9zQqCaaUNzSil 8qFrtNCM3Nc= =sDAk -----END PGP SIGNATURE-----