telecom@ucbvax.ARPA (09/29/84)
From: Jon Solomon (the Moderator) <Telecom-Request@MIT-MC>
TELECOM Digest Saturday, 29 Sep 1984 Volume 4 : Issue 93
Today's Topics:
Hi-tech answering machines
Codex 224
ringing only once
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Date: 26 Sep 84 1817 PDT
From: Allan A. Miller <AAA@SU-AI.ARPA>
Subject: Hi-tech answering machines
I am looking for a phone answering machine with the following
features:
full function beeperless remote control;
security code. I found one from Radio Shack in the 85
catalog, Sharper Image has one from Panasonic, Codaphone has one.
They are about 250$. However, none of them seem to allow user
changeable security codes. Does anyone have any experience with these
units or know of any others that have the required features? Please
answer directly to AAA@SU-AI as I am not on the list.P
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Date: 27 September 1984 02:14-EDT
From: Minh N. Hoang <MINH @ MIT-MC>
Subject: Codex 224
I work for Codex... in the department that handles the 224 development
coincidentally. I checked into your Tip and Ring reversal problem and
I guess it does exist if you expect the modem to reverse Tip and Ring
between the Telco and Telset jacks.
At the Telco jack, T, R, MI, MIC and the programming resistor leads
are arranged according to the RJ45S specification in FCC part 68
requirements. English translation: that jack has the same alignment
as the one on the wall if you don't use the other leads (exclusion-key
telephone, programmable mode DAA.) Similarly the Telset jack is RJ11
and also looks like the one on the wall. So the standard modem board
just pass T/R through. We did put provision into the printed circuit
wiring so that T/R can be reversed on board but that has to be done by
a technician (ours, according to pt. 68). That involves cutting 2
wire straps and installing 2 other.
But don't get your tools yet. The cable(s) we supply with the unit do
not
-- should not -- reverse T/R. The plugs should have the same
alignment. You might have gotten a 'defective' cable, I have seen a
few 8-pinners reversed... Anyway, phones without diode protection
aren't that rare. But they are like acoustic-coupling modems...
On the lighter side, thanks for the indirect compliment to our modem's
performance. Hmm... if y'all want errors maybe we shouldn't spend
those few months tweaking the adaptive equalizer. The modem was
designed to work well over international circuits - as a V.22 bis.
Thus you will have problem determining the bit error rate over typical
ATT-C lines. We did digital loopback tests overnight to our remote
beta sites and collect 1-2 errors in >12 hours. A high of about 10
was collected over a 3-day weekend... If you want to characterize the
modem seriously, you will need a telephone channel simulator to
introduce controlled amounts of noise, phase jitter etc. For BER
test, we generally use the standard 2047 pseudo-random pattern along
with those bit-error rate tester. Well, the modem isn't sensitive to
that either.
Cheers.
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Date: Thu, 27 Sep 84 07:38:11 est
From: ECN.davy@Purdue.ARPA (Dave Curry)
Subject: ringing only once
Several years ago, ringing everybody's number once to see how many
phones he had used to be one of GTE's (Lafayette, Indiana) favorite
pasttimes. They stopped doing this 7 or 8 years ago, supposedly
because some guy sued his telco for invasion of privacy or some such
and won. GTE, being afraid of getting sued, stopped trying to spy on
its customers this way.
I'm not sure if the above is correct -- perhaps someone who follows
the phone laws can confirm or correct it. I do know, however, that GTE
(at least around here) does not do any of that stuff anymore. Perhaps
all the deregulation has something to do with it too -- maybe some of
those little "beep-beep" ringers don't show up like they should, or
maybe so many people have extra phones now it just isn't worth the
hassle.
--Dave Curry {decvax, ihnp4, ucbvax}!pur-ee!davy eevax.davy@purdue
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Date: Fri, 28 Sep 84 14:58 EDT
From: Kahin@MIT-MULTICS.ARPA
MIT Communications Forum
COMPETITION FOR INTELSAT
Thursday, October 18, 1984, 4-6 p.m.
Marlar Lounge, Bldg. 37-252, 70 Vassar St., MIT, Cambridge
For two decades INTELSAT has had a near monopoly of international
satellite telecommunications. This was justified on many of the same
grounds as AT&T's monopoly of domestic telephony: the merits of
uniformity and standardization; cross-subsidy of less-developed by
more developed areas; and economies of scale.
Orion Satellite and several other potential competitors have recently
applied to serve the lucrative North Atlantic routes. This has
touched off intense debate about "cream-skimming," the value of
INTELSAT, and America's international communications policies.
Christopher Vizas, Orion Satellite Corporation
Joseph Pelton, INTELSAT
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End of TELECOM Digest
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