Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!mailrus!accuvax.nwu.edu!nucsrl!telecom-request
From: dave%westmark@uunet.uu.net (Dave Levenson)
Newsgroups: comp.dcom.telecom
Subject: Re: Centrex and 9xxx Numbers
Message-ID: <4365@accuvax.nwu.edu>
Date: 23 Feb 90 02:10:51 GMT
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X-Telecom-Digest: Volume 10, Issue 128, Message 7 of 12


In article <4112@accuvax.nwu.edu>, djcl@contact.uucp (woody) writes:

> Several years ago, the University of Toronto used a Centrex that took
> up most of the 978 exchange. However, since extensions couldn't start
> with 9 (dial 9 to get local dial tone), there was a gap in the 978

> Perhaps there are other examples of the -9xxx gap where Centrex, or
> other direct-dial extension systems are used out there...

Most Centrex groups use less than a full 10,000 numbers, and so there
are ordinary subscriber lines with numbers having the same prefix.
The 0xxx and 9xxx groups are generally not assigned to centrex, so as
to provide attendant and 'outside' access.  Sometimes there are other
centrex groups with the same prefix, but members of one group must
dial 9+ 7 digits to reach members of the other.  Remember, a centrex
is generally not a physical switch, it's a software-defined group of
lines (with a group of numbers) which subscribe to a special group of
features.


Dave Levenson			Voice: (201 | 908) 647 0900
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