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Xref: sserve comp.sys.powerpc:35562 comp.sys.intel:33241 comp.unix.bsd:16372 comp.unix.pc-clone.32bit:8282 comp.unix.sys5.r4:9435 comp.unix.misc:16381 comp.os.linux.development:24072 comp.os.linux.misc:36549 comp.os.386bsd.development:3296 comp.os.386bsd.misc:5597 comp.os.misc:3893 Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!bunyip.cc.uq.oz.au!tmxbris!stallion.oz.au!stallion.com!uu4news.netcom.com!netcomsv!ix.netcom.com!howland.reston.ans.net!agate!news.mindlink.net!giant!a09878 From: a09878@giant.rsoft.bc.ca (Curt Sampson) Newsgroups: comp.sys.powerpc,comp.sys.intel,comp.unix.bsd,comp.unix.pc-clone.32bit,comp.unix.sys5.r4,comp.unix.misc,comp.os.linux.development,comp.os.linux.misc,comp.os.386bsd.development,comp.os.386bsd.misc,comp.os.misc Subject: Re: flat rates for Internet/phone (Re: X on dial-in) Date: 14 Mar 1995 08:09:01 GMT Organization: MIND LINK! Communications Corp., Langley, BC, Canada Lines: 30 Message-ID: <3k3iut$1bt@deep.rsoft.bc.ca> References: <D3s19v.4M7@pe1chl.ampr.org> <3jjn6e$4oi@trance.helix.net> <3jla66$hvi@park.uvsc.edu> <3k1fh9$f19@m1.cs.man.ac.uk> NNTP-Posting-Host: giant.mindlink.net In article <3k1fh9$f19@m1.cs.man.ac.uk>, Donal K. Fellows <fellowsd@cs.man.ac.uk> wrote: >Someone (I forget who) effectively made the claim that phone switches >are based on a bus architecture. Anyone who built a system like that >ought to expect to be shot, as there are switch networks that can >carry much higher loads for very little cost (and can deal with much >more in the way of pathological cases... :) That was probably me. We just bought an AT&T Definity 3 PBX, which is their latest model in that series. (It was introduced within the last year or two.) It uses a 32 Mbit internal serial bus which is divided into 512 64K channels via time-division multiplexing. It seems a reasonable design to me. A 32Mbit serial bus is cheap, quite reliable, and it can easily be extended between cabinets with fiber-optic cable. I'm not sure what pathological cases this runs into that other systems do not. I'm not sure what systems are cheaper, either. Perhaps you could enlighten me. I should note that this is quite a small PBX, though, designed to serve about 8000 people. (Well, it's large for a PBX, but small for a CO.) cjs -- Curt Sampson a09878@giant.rsoft.bc.ca Opinions are mine, Fluor Daniel Wright, Ltd. 604 488 2226 not Fluor Daniel's. 1075 W. Georgia Street Vancouver, B.C., V6E 4M7 De gustibus, aut bene aut nihil.