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
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Date: 26 Sep 89 03:07:30 GMT
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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