Path: utzoo!telecom-request Date: Fri, 5 Apr 1991 10:12:03 +1000 From: rodney@pico.qpsx.oz.au Newsgroups: comp.dcom.telecom Subject: Re: Info Wanted on B_ISDN. Message-ID: Organization: TELECOM Digest Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 273, Message 1 of 9 Lines: 44 Jim Niemann writes: > What research is being done in broadband ISDN? Is it possible to > purchase a prototype switch that supports it? > Where should I look for more info? Others have written various things about primary rate access etc. Well, that's incorrect. Primary rate is for normal ISDN. B_ISDN or Broadband ISDN is a connection oriented service at very high data rates. Most people regard it as having data rates in excess of 50 Mbits/sec, up to at least a couple of Gbits/sec. It uses what is known as ATM switching, or Asynchronous Transfer Mode Switching, based on small data units referred to as cells, which are a fixed length. It operates on point to point links between ATM switches, and carries anything, for example, packet switched and isochronous data. Routing is performed using VCI (Virtual Circuit Identifiers). So, the short answer is: A hell of a lot of research is being done. Most of it in development of ATM switches that work well. A lot of work is being done in deciding just what services should be offered, and people are working on standardization. You could possibly find someone who knows someone who has a prototype ATM switch, and it is possible (after AT&T's announcement of the BNS2000 cell switch) that AT&T might have something. Don't hold your breath though, because as I understand it, AT&T has started and stopped work on ATM switches at least twice, and the BNS2000 *is* a fast packet switch than can (might?) use ATM. I would guess that you don't have lots of options in getting a prototype switch. As for more information, well, a lot of papers have been written on this, and there are a couple of standards, published by CCITT. The reference numbers elude me at present....... In the meantime, there's always our 802.6 ;-) Any more queries, direct them to me at rodney@pico.qpsx.oz.au If that doesn't work, tack @munnari.mu.oz.au on the end. Cheers, Rodney Van Luinen QPSX Communications Pty Ltd 33 Richardson St WEST PERTH WESTERN AUSTRALIA.