Date: Mon, 28 Dec 92 11:51 GMT
From: Richard Cox <mandarin@cix.compulink.co.uk>
Newsgroups: comp.dcom.telecom
Subject: Demarcs and Shared Wiring
Reply-To: mandarin@cix.compulink.co.uk
Organization: TELECOM Digest
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X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 924, Message 7 of 11

I was intrigued by some of Pat's comments on the cost of installing
new lines.

Commenting on a posting by mrosen@nyx.cs.du.edu (Michael Rosen), Pat
said:

> try it yourself in an older highrise with a real messy demarc and
> hundreds or thousands of house pairs to deal with and you'll wish
> you'd spent the $75, believe me you.

Over here we are not allowed to have any other service in the same
cable as an exchange pair, downstream of the demarc (which we call an
NTTP - Network Test and Termination Point).  Having more than one
customer's services in a single cable (which the telco does not
manage) seems to open up a large can of worms/possibilities of
maintenance conflict, fraud, etc.

How did this situation come about in the US? Are there any proposals
to "regulate" it?


Richard D G Cox

Mandarin Technology, Cardiff Business Park, Llanishen, CARDIFF, Wales CF4 5WF
Voice: +44 222 747111      Fax: +44 222 711111      VoiceMail: +44 399 870101
E-mail: mandarin@cix.compulink.co.uk     Not diallable on 511 in mainland USA


[Moderator's Note: In the USA, much of the wiring goes back to long
before divestiture -- when there was but a single Mother Company, and
who cared?  Lots of demarcs and the 'house pairs' from them are fifty
years old or more. Example: A building nearby, whose basement I am
familiar with has a demarc with four hundred house pairs and about
three hundred pairs coming in from the CO to serve the two hundred or
so apartments in the (thirty story) building, constructed in 1927.
When new service is requested, if telco records do not show a CO pair
which has been wired 'straight through' to a house pair and then to
the apartment, a technician comes out, locates the assigned CO pair on
one side of the demarc and punches it down on the other side where the
house pairs terminate. Sometimes telco records say the pair is already
wired through and the tenant's phone still does not work so the tech
has to come out. All the pairs from the CO are multipled; that is they
show up on the demarcs of other buildings nearby. A certain number of
house pairs are also multipled in such a way that a tenant who wants a
second line may wind up getting a house pair that previously had
served as a line for another apartment. Some house pairs are multipled
between the 'local demarcs' located on each floor of the building in a
janitor's closet.

Records kept at the demarc are notoriously out of date and frequently
inaccurate. In the building I am speaking of now, one punchdown block
with fifty pairs on it sits sort of apart from the rest and has a
penciled note written on the wooden backboard: "This fifty pairs is
multipled to the new building across the street." (signed) J. Gordon,
May 12, 1936 ... and another note, apparently by the same long-
forgotten probably dead 'J. Gordon' says "Rogers cable 95 went open
and I took five pairs from here for the switchboard."  Not only that,
but when you take the big wooden doors off the demarc cabinets, dust
and cob-webs greet you, and cockroaches scurry away to hide.   PAT]