Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!bellcore!texbell!vector!telecom-gateway From: mit-amt!geek@media-lab.MEDIA.MIT.EDU (Chris Schmandt) Newsgroups: comp.dcom.telecom Subject: Re: ISDN Subscriber Equipment Message-ID:Date: 26 Sep 89 03:07:30 GMT Sender: news@vector.Dallas.TX.US Reply-To: Chris Schmandt Organization: MIT Media Lab, Cambridge MA Lines: 17 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 411, message 2 of 8 In article fff@mplex.UUCP (Fred Fierling) writes: >... I understand that it would be possible for two >independent calls to be handled on each of the B channels. So, how would >both telephones perform call set up and tear down on the one D channel? Not an issue. No different from setting up a voice call on the B1 channel and a data call on the B2 channel with today's sets. (my experience being limited to the AT&T 7506 set). During a "call", the D channel is in no way "dedicated" or tied to it. Q.931 provides bit fields to support connections to several entities simultaneously. In fact, while handling the above scenario I suspect you could also sustain an X.25 data link over the D channel, be reporting gas meter usage, etc. all at once. chris