From owner-freebsd-hardware Thu Jul 11 07:01:33 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id HAA12118 for hardware-outgoing; Thu, 11 Jul 1996 07:01:33 -0700 (PDT) Received: from zoo.toronto.edu (zoo.toronto.edu [128.100.72.1]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id HAA12111 for ; Thu, 11 Jul 1996 07:01:28 -0700 (PDT) Date: Thu, 11 Jul 1996 10:01:11 -0400 (EDT) From: Henry Spencer Subject: Re: cable vs. ISDN To: "Jacob M. Parnas" cc: hardware@freebsd.org, bsdi-users@bsdi.com In-Reply-To: <199607110404.AAA00651@jparnas.cybercom.net> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hardware@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > >the hardware used for the Rogers prototype talked to the computers by > >Ethernet. > > As pointed out earlier, isn't ethernet tcp/ip based or some other network > protocol based... The question is phrased poorly, and is ambiguous, so I'll answer both interpretations. :-) Is Ethernet tied to a specific protocol, like TCP/IP? No. Ethernet just gets a packet from point A to point B, accompanied by a checksum (well, CRC) and a type indicator. Any other structure is imposed by software. Do you need to use a non-trivial protocol of some kind to make use of Ethernet? In principle, no, but in practice, yes. However, this is not necessarily a bad thing, because talking to network or a complex device invariably involves a protocol *anyway*... and better you should use a well-designed one that your software already supports. The alternative is not to do without a protocol, but to use some kludged-up mess invented by the hardware vendor, typically undocumented and buggy. (I've written device drivers.) I'd much rather have the hardware supplier use a standard protocol that I have debugging tools for. Henry Spencer henry@zoo.toronto.edu