Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!bellcore!texbell!vector!telecom-gateway
From: goldstein@delni.enet.dec.com
Newsgroups: comp.dcom.telecom
Subject: Re: ISDN Subscriber Equipment
Message-ID: 
Date: 25 Sep 89 21:55:28 GMT
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X-TELECOM-Digest: volume 9, issue 411, message 3 of 8

In article , fff@mplex.UUCP (Fred
Fierling) writes...
>>From what I've read I understand that the U interface would be provided
>via an single pair coming from the CO to the subscriber's premises and
>terminate on an NT1 box which would provide the S/T interface to all
>digital telephones on the premises.
>Assuming this is correct, 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?

The D channel has a contention-resolution protocol associated with it.
Each terminal  has a unique address (TEI) so the network knows which one
is which; there's a procedure for auto-assigning TEIs, or they can be
manually set.  The TEI is part of the LAPD protocol, essentially a
variant on LAPB with multiplexing.

      Fred