From owner-freebsd-hackers Sat Sep 27 09:35:41 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id JAA00808 for hackers-outgoing; Sat, 27 Sep 1997 09:35:41 -0700 (PDT) Received: from sabre.goldsword.com (sabre.goldsword.com [199.170.202.32]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id JAA00790; Sat, 27 Sep 1997 09:35:33 -0700 (PDT) Received: (from jfarmer@localhost) by sabre.goldsword.com (8.8.7/8.7.3) id MAA17779; Sat, 27 Sep 1997 12:13:14 -0400 (EDT) Date: Sat, 27 Sep 1997 12:13:14 -0400 (EDT) From: "John T. Farmer" Message-Id: <199709271613.MAA17779@sabre.goldsword.com> To: hackers@FreeBSD.ORG, stable@FreeBSD.ORG, tlambert@primenet.com Subject: Re: 'fxp' driver/hardware lossage (was Re: Alexander B. Povol's mail) Cc: dg@root.com, jfarmer@goldsword.com, rgrimes@GndRsh.aac.dev.com, tarkhil@mgt.msk.ru Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Sat, 27 Sep 1997 11:42:14 +0000 (GMT) Terry Lambert said: [somebody else...] >> } Only broken NIC chips are simplex, even the 82586 is actually capable >> } of hering itself talk on the wire, though most drives do not set >> } the chip into this mode. Either way ``ethernet is _not_ a simplex >> } device''. >> >> That's only true of coaxial media. Over twisted pair, if you see >> data start arriving on the receive pair while your transmitting then >> you have to assume that the data is being sent by another station >> and you've got a collision situation. > >Isn't this the hub's responsibility to distinguish and prevent? > A hub that does this is usually called a "switch" :^> However, a hub that supports full-duplex links _must_ deal with some of the collision issues but a simpler level than a switch does. John ------------------------------------------------------------------------- John T. Farmer Proprietor, GoldSword Systems jfarmer@goldsword.com Public Internet Access in East Tennessee dial-in (423)470-9953 for info, e-mail to info@goldsword.com Network Design, Internet Services & Servers, Consulting