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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.mel.connect.com.au!news.syd.connect.com.au!news.bri.connect.com.au!corolla.OntheNet.com.au!not-for-mail From: Tony Griffiths <tonyg@OntheNet.com.au> Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Socket drivers for SCSI -- FDDI/Ethernet is better Date: Thu, 15 May 1997 11:41:04 +1000 Organization: On the Net (ISP on the Gold Coast, Australia) Lines: 34 Message-ID: <337A69B0.14F7@OntheNet.com.au> References: <337329C5.A5678A08@isr.co.jp> <5kvoik$5hj@uriah.heep.sax.de> <3374492B.C490C5DE@isr.co.jp> <5l6iql$8k5@verdi.nethelp.no> <5l7om0$5nk@uriah.heep.sax.de> Reply-To: tonyg@OntheNet.com.au NNTP-Posting-Host: swanee.nt.com.au Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0 (WinNT; I) Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:40878 J Wunsch wrote: > > sthaug@nethelp.no (Steinar Haug) wrote: > > > Frankly, I don't understand why anybody would want to use SCSI for high > > speed networking - it was never meant for that! If you really, This is indeed true... The command/response flavour of SCSI does not lend itself to inter-processor communications. A disk drive, even a _smart_ one, does not simply get the "idea" of transfering a Meg or more of data to a host in the hope that this will be useful. Basically with SCSI, all operations of 'slave' devices are directed and managed from a master device. While it is possible to have 2 master devices (at different SCSI ids) on the bus at once, I don't think that both can be operational simultaneously (ie. one is in stand-by mode ready to go if the other master "fails"). *really* > > need QOS in your networks today, buy ATM. Otherwise, 100 Mbps Ethernet > > is certainly the way to go (simpler and less expensive - current best > > price is around $340 for full duplex NIC + switch port). > > There's also FDDI. While it doesn't guarantee QOS, i think it will > guarantee a some maximum propagation delay, since it's a dual > token-ring. But i'm fairly clueless about the details either. I > don't think SCSI is the way to go for this, however. With FDDI (or at least with the glass variety) it is possible to have to 2 NICs connected with a simple cross-over (Tx <-> Rx) without a hub of any variety, allowing cheap (?) high-speed inter-cpu communications! The performance should be better than 100 Mbps Ethernet (although possibly not as good as the full-duplex version) as the maximum MTU for FDDI is 4500 bytes .v. 1500 bytes for Ethernet. Tony