Date: Mon, 12 Oct 92 20:55 EDT
From: fmsys!macy@usenet.INS.CWRU.Edu (Macy Hallock)
Newsgroups: comp.dcom.telecom
Subject: Re: Network Installation Box Installation Rules
Organization: The Matrix
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 12, Issue 777, Message 6 of 7

In an attempt to put some factual information back into this thread, I
present the following:

In general, Network Interface rules are goverened by:

FCC rules
National Electrical Code
PUC rules
Telco policy
Local telco whim

(Not neccessarily in that order, BTW)

The current trend is toward the Minimum Point of Penetration (MPOP)
rule.  The idea being that the telco's regulated facilities should end
at the MPOP into a customer location.

Normally this is the entrance or point of contact within the building
in question.

In residential facilites, especially single family dwellings, the
trend is to locate the Network Interface (NI) in a weatherproof
enclosure on the side of the dwelling, outdoors, for both aerial and
buried entrances.

I find this "rule" to be somewhat flexible, though.  In the case of a
buried entrance, we often prefer a completely concealed entrance for
security reasons.  If we work with the telco, i.e. open the trench
area next to the dwelling and cut a hole throught the block basement
wall, the telco will usually cooperate and install the NI in the
basement right next to the entrance through the wall.  Many telco
installers actually prefer this method, if someone else does the dirty
work [grin].

For aerial entrances, there is less flexibility.  In years past we
would be able to gain telco cooperation in relocating the NI or
protector in the attic area.  Due to access problems, and the
increased sensitivity to grounding concerns on the part of telco
personnel, this is much more difficult to accomplish these days.
Where security is an issue, we now arrange for a new buried entrance,
rather than attempt attic placement of an NI.

In commercial establishments and in multifamily buildings, interior
location of the MPOP and NI is common.  This is often due to the use
of buried conduits for these type of buildings.  In existing
structures, the multipair cable is usually already constructed to an
interior multipair protector, and the telco considers this to be the
MPOP and located all NI's there.

I have seen a few exterior NI's on commercial sites, but usually where
only one or two phone lines are involved and the feed is drop wire as
opposed to multipair cable.

Where the jacks or other termination is distant from the NI, such as
in an apartment/multifamily dwelling, all wiring, whether existing or
new, is regarded as customer owned inside wiring.  The regulated telco
facility ends at the NI.  This has proven to be somewhat problematical
in the case of T1 circuits and other sensitive data facilities, BTW.

Where the desired point of demarcation is different from the MPOP, the
NI is at the MPOP and the wiring to the demarc is treated as customer
owned inside wire.  This means that charges for inside wire
installation are incurred if the demarc is not at the same location as
the MPOP/NI.  It also means that if you don't pay for inside wire
maintenance and the demarc is distant from the MPOP, then billable
service charges can be applied by the telco for sometimes very flimsy
reasons.


Macy M Hallock Jr N8OBG 216.725.4764 macy@fmsystm.uucp macy@fmsystm.ncoast.org
[No disclaimer, but I have no real idea what I'm saying or why I'm telling you]