telecom@ucbvax.ARPA (04/05/85)
From: Jon Solomon (the Moderator) <Telecom-Request@BBNCCA>
TELECOM Digest Tue, 2 Apr 85 20:52:47 EST Volume 4 : Issue 175
Today's Topics:
Multi-line telephones for residential use
T1 framing requirements
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Date: 1 April 1985 22:28-EST
From: Jon Solomon <JSOL @ MIT-MC>
To: telecom @ BBNCCA
Can anyone furnish me with a complete list of common carriers
serving the Boston area and their equal access prefix codes? I want
to do a survey on quality vs. price so I can decide which one
will best serve my needs.
Thanks,
--JSol
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Date: Tue, 2 Apr 85 14:23:55 PST
From: "Theodore N. Vail" <vail@UCLA-LOCUS.ARPA>
To: telecom@bbncca.arpa
Subject: Multi-line telephones for residential use
Sometime ago I asked telecom readers about multi-line telephones for
residential use, which could serve more than two lines. Since then I
have learned of two:
Another telecom reader mentioned that at Winter Consumer Electronics
Show in January, Teleconcepts announced a product called the
"FeaturePhone V", an instrument which was said to have the ability
to handle three central-office trunk lines. According to a company
spokesman, it has just a single "in-use" light that shows both actual
use and a "hold" condition, but apparently some form of remote pick-up
is supported. Its wiring requirement is said to be just the 3 trunk
pairs.
This phone was being promoted for use in residential installations, but
it's not clear that Teleconcepts will actually get it into wide retail
distribution. Because very few residences have three trunks, the market
for it seems to be small. For more information contact
Teleconcepts Inc.
22 Culbro Dr.
West Hartford, CT 06110
203/666-5666
I have found (and bought) a four-line phone at (of all places) the
Radio Shack Telephone/Computer Store in Santa Monica, selling for about
$170.00. It provides essentially all of the features of a standard
teleco office keyset without requiring special wiring (aside from the
standard two wires per line). It does require a low-voltage supply
(9v DC) and a battery backup.
The functional differences are
1. The display consists of 4 green led's (not red).
2. When a line is ringing, the corresponding led flashes only when the
bell is ringing (there is no trigger to keep it going continuously
until that line is answered). The hold and in-use signals are as
usual.
3. It is not as sturdy as the telco instrument.
4. It provides a modular jack into which can be plugged a dialer, a
speaker phone, etc. This is connected in parallel with the built-in
instrument. The current flow obtained when the instrument is
off-hook signals the other equipment (no special switching is
required).
5. It connects to the lines using 1 to 4 RJ11 modular jacks (which
can be 1 or 2 line, per FCC specs) instead of using a 50 conductor
amphenol plug.
The hold is of a type common in residential two line instruments. A
simple circuit (one for each line) maintains the current flow and holds
the line. When any instrument on that line is picked up, the lowered
impedance causes a voltage drop, which the hold circuit senses, causing
it to release.
I have had it for about two months with no problems yet.
[I have no business or personal affiliation with Teleconcepts or Radio
Shack. Nor have I ever seen the FeaturePhone V.]
ted
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Date: Tue, 2 Apr 85 12:51:32 pst
From: amdcad!phil@decwrl.ARPA (Phil Ngai)
To: decwrl!telecom-request@bbncca.ARPA
Subject: T1 framing requirements
I believe the phone companies have alarm circuits which go off when
the T1 framing information is invalid. Even assuming they would be
willing to turn off or ignore the alarm on your non-conforming datastream,
isn't being able to take advantage of the phone company's diagnostic
equipment worth the cost of putting in at least the 193th bit framing
information?
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End of TELECOM Digest
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