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From: jss@sjuvax.UUCP
Newsgroups: net.micro
Subject: Re: 'call waiting' feature interferes wi - (nf)
Message-ID: <368@sjuvax.UUCP>
Date: Tue, 12-Jun-84 19:19:16 EDT
Article-I.D.: sjuvax.368
Posted: Tue Jun 12 19:19:16 1984
Date-Received: Thu, 21-Jun-84 01:18:57 EDT
References: <291@sri-arpa.UUCP>
Organization: Saint Josephs Univ. Phila., Pa.
Lines: 26

[Arent you hungry...]
	Call forwarding will *NOT* work - our site is on a PBX and we
looked into this extensively.  On many PBX's, call forwarded calls first
test the initial target phone and then transfer if it is in use.  In
between the check and the transfer, a disconnect (briefly) is incurred.  It
is quite long enough for your computer to hang up.  Further, the call
forwarded *FROM* is briefly interrupted by the check - just as though a
real operator had interrupted you to check the line in the real world.
That interruption is more than enough for the computer to say forget it and
hang up.  The right way to handle this is to implement (at least on AT&T
PBX's) something called Data Restriction and or Data Privacy (the first is
more important).  Data Restriction insures that come hell or high water,
not even the local operator can break the line.  Nor, of course, can call
forward, so call forwarded calls are perceived as busied out.  Then you
must install line hunt software.  The line hunt software does not interrupt
any conversations and verifies the connection before it is made. 

	This is the *ONE* part of our datacomm over telephones that we have
never had troubles with.

Good luck

Jonathan Shapiro
System Manager
Haverford College
Haverford, Pa.