rodney@pico.qpsx.oz.au (04/05/91)
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.
Keith Junker <keith@ntia.its.bldrdoc.gov> (04/10/91)
In article <telecom11.273.1@eecs.nwu.edu> rodney@pico.qpsx.oz.au writes: > 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? > 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....... Regarding only the technical aspects and not the availability of B-ISDN switches, one such document is, and here I will attempt to reproduce its cover sheet: COMMITTEE T1 - TELECOMMUNICATIONS STANDARDS CONTRIBUTION DOCUMENT NUMBER: T1Q1.3/90-001R2 DATE: JANUARY 18, 1991 STANDARDS PROJECT: Specification and Allocation of Performance for ISDN (T1Q1-10) SUBJECT: 1990 B-ISDN Recommendations ORIGINATOR: ISDN Experts of Study Group XVIII KEY WORDS: Broadband ISDN (B-ISDN), 1990 Recommendations, CCITT, Accelerated Procedures DISTRIBUTION: T1Q1.3 Working Group Abstract: This contribution, an update of T1Q1.3/90-001R1, provides copies of 13 Broadband ISDN (B-ISDN) Recommendations, which Study Group XVIII unanimously approved at its December 1990 meeting for invocation of Resolution 2 (accelerated approval) procedures. The December 1990 version of the B-ISDN Recommendations made only minor editorial changes to the versions approved by WP XVIII/8 at its June 1990 meeting in COM XVIII-R 34-E. The attached copies of COM XVIII-R 34-E have been updated to reflect the changes reported in Temporary Document 9/XVIII, "1990 B-ISDN Recommendations - Proposed Editorial Amendments," by the Chairman of WP XVIII/8. A report of the December 1990 meeting of Study Group XVIII is provided in T1Q1.3/91-001. The B-ISDN Recommendations provide a stable basis for the development of related B-ISDN performance Recommendations. Copies of the ISDN performance Recommendations from the December 1990 meeting of Working Party XVIII/6 are provided in T1Q1.3/91-002. Obviously, this abstract is intended for internal use, but it indicates the nature of the activity going on concerning B-ISDN at this time. One way to get more information or this particular document is to join the committee(!) Keith E. Junker U.S. Dept. of Commerce NTIA/ITS.N3 325 Broadway Boulder, CO 80303 (303) 497-3376 keith@ntia.its.bldrdoc.gov