Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!wuarchive!decwrl!hayes.ims.alaska.edu!accuvax.nwu.edu!nucsrl!telecom-request
From: floyd@hayes.ims.alaska.edu (Floyd Davidson)
Newsgroups: comp.dcom.telecom
Subject: Re: What is "Supervision"?
Message-ID: <14205@accuvax.nwu.edu>
Date: 31 Oct 90 14:50:59 GMT
Sender: news@accuvax.nwu.edu
Organization: University of Alaska Fairbanks
Lines: 29
Approved: Telecom@eecs.nwu.edu
X-Submissions-To: telecom@eecs.nwu.edu
X-Administrivia-To: telecom-request@eecs.nwu.edu
X-Telecom-Digest: Volume 10, Issue 779, Message 5 of 13


In article <14174@accuvax.nwu.edu> HIGGINS%FNAL.BITNET@uicvm.uic.edu
(Bill Higgins-- Beam Jockey) writes:

>I think many TELECOM Digest postings would become clear to me if I
>just understood one jargon word.

>What is meant by "supervision?"

Supervision in it's simplest terms is any control signal that
indicates whether your phone is on hook or off hook.

When you go off hook the line switcher see's that there is now current
on your loop (off hook supervison) ... You dial your friend in Alaska
and your toll switch needs to know when the distant end is off hook...
That used to be done with a 2600 Hertz tone on the circuit, but now it
is sent via a data circuit that is entirely separate from the circuit
you talk on.

Technically any control signal that indicates the status of one part
of a circuit, or piece of equipment, to another is a supervisory
signal.  But what everyone is always refering to is hookswitch
supervison.



Floyd L. Davidson   floyd@hayes.ims.alaska.edu    floydd@chinet.chi.il.us
Salcha, AK 99714    connected by paycheck to Alascom, Inc.
When *I* speak for them, one of us will be *out* of business in a hurry.