[comp.dcom.telecom] Poor Design of Telephone System

thomas@mvac23.uucp (Thomas Lapp) (02/24/90)

>From: Dan "the Man with the Plan" Ross <dross@fluffy.cs.wisc.edu>
>Subject: Re: Centrex and 9xxx Numbers
>Date: 22 Feb 90 08:00:38 GMT
>Organization: U of Wisconsin CS Dept

>part of the 495 exchange.  Intracampus calls are made by the last _5_
>digits, so there are numbers of the form 471-9XXX.  The dorm
>"exchange" includes 495-5XXX and 495-3XXX and possibly more.  The gap

>The fun arises when you dial a number 495-XXXX from on campus; unless
>you know someone lives in the dorm, you just have to try it:
>9-495-XXXX or 5-XXXX.  (There are state and city offices, as well as a
>cookie store (!) on 495-XXXX.)  And the wrong one will not work!

This brings to mind the sad story of the installation of a new phone
switch by West Virginia University Hospitals, Inc. to service their
brand new hospital.

The background: The old hospital was associated with the University
and thus was part of the university-owned Centrex system.  All
university numbers are of the form 293-xxxx.  When dialing within the
Centrex, only the last 4 digits are needed.  However, when the new
hospital was built, it was (and is) owned by WVUH, Inc, which is a
private company.  They decided that they would install their very own
Rolm switch and also leased?  the 598-4xxx from the local phone
company.  This meant that if you are in the community, you can dial
someone's hospital room with 598-4xxx.

Now here is where the poor planning comes into play.  They found that
1000 numbers wasn't enough for the hospital, and so they added the
3xxx series to the Rolm switch.  However, they did not get this group
from the local phone company, which means that 598-3xxx is guaranteed
to not be a number at the hospital.  So from within the hospital there
are a bunch of internal-only telephone numbers (mostly nurses stations
and numbers that people outside the hospital really shouldn't need to
call).

But the problem gets worse.  Many of the doctors do not have offices
in the new hospital, but still have their offices in the old building
which is served by the Centrex system.  Due to cost and probably
politics, it was decided that they would keep their old phones and not
receive service off of the Rolm switch.  But doctors ARE one community
that would have a need to access the 3xxx internal-only numbers in the
new building.  Beginning to see the problems?

One solution might be that a system be set up so that when they dial
3xxx or 4xxx from their Centrex phone, that it go to the Rolm switch
and be routed correctly.  However, that was out since 3xxx and 4xxx
are already assigned numbers elsewhere on campus on the Centrex.  So
the solution was to put a 'key' in front of the number in order to
force the call to be routed from Centrex to Rolm or vice-versa.  The
third thing wrong here was that Rolm and the Centrex can't use the
same prefix on numbers.  

So if you are calling from Centrex to Rolm, you preface the number
with "*1" and if going the other way you have to preface with "11".  A
most undesirable solution, since it requires that you know where you
are and where you are trying to get to and you have to memorize two
methods of calling.

The last item does not relate directly to the telephone switches
themselves but do relate.  Some years ago, the hospital migrated from
voice pagers to digital pagers which display four digits in sequence
using one LED digit.  That was fine when it was installed.  When 4095
showed up, you dialed 4095 and it went through.  However, now that
there are two sets of 3xxx and 4xxx, there is no way to tell if you
are being paged for 293-4095 or 598-4095 when 4095 shows up in the
display.  So the bright folks in administration decided that numbers
in the new hospital are to be paged as 5xxx and 6xxx (ie. take number,
add 2000 to it, then enter that as the page).  This is nice if you
remember to do this.  Or remember that it is the new building which
has to have 2000 added rather than the old building.

Voice paging over the two building intercom system gets kind of funny
too.  "Dr. Weiser, please call 4565 in Ruby" or "Dr. Jones, please
call 4354 Health Sciences" (Ruby = Ruby Memorial = Rolm; Health
Sciences = Centrex).  Oh the joys of being able to operate your very
own phone company.  Looks like the learning curve for some people is
going to be pretty steep.

I guess the obvious solution in this case would be to install 5 digit
dialing for extensions within either system.  But I guess since the
University did not want to have to change the way the ENTIRE
university dialed extensions, they did not go this route.

                         - tom

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[Moderator's Note: This reminds me of a department store in downtown
Chicago which had centrex for how many ever years. ROLM sold them a
bill of goods, so they dumped centrex for a ROLM switch. They kept all
the numbers they had under centrex and set them up as DID to ring
straight through to the extensions they had always been on. But like
your case, they needed more extensions so they installed a bunch on
the ROLM that do *not* relate back to the identical CO number. Only
they never bothered to explain all this to the employees with the new
style extension numbers who assumed they too could receive calls from
their personal friends all day without going through the store
operator.  For almost a month, Chicago City Colleges (the people with
the CO numbers like the new extensions at the store) wondered why they
got all those wrong numbers. Talk about Dumb with a capital /D/.  PT]