telecom@ucbvax.ARPA (02/26/85)
From: Jon Solomon (the Moderator) <Telecom-Request@BBNCCA>
TELECOM Digest Tue, 26 Feb 85 6:39:54 EST Volume 4 : Issue 163
Today's Topics:
Re: Electronic Mail Directory
Telebyte 'Accelerator' Data Compression Box
Md. pay phones
Residential PBX; T-1
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Date: Thu, 21 Feb 85 16:07:48 EST
From: Ron Natalie <ron@BRL-TGR.ARPA>
To: adrion%ucbingres@ucb-vax.ARPA
Subject: Re: Electronic Mail Directory
There is also a UUCP users directory that is done by Rich Kiessig.
He periodically asks people to send him their info if they want to
be in the next copy of the directory.
-Ron
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Date: Sat, 23 Feb 1985 09:42 EST
From: GZ.PC%MIT-OZ@MIT-MC.ARPA
To: Eliot Moore <SWG.ELMO@USC-ISIB.ARPA>
Cc: telecom@MIT-MC.ARPA
Subject: Telebyte 'Accelerator' Data Compression Box
They could be for real, as long as you're shipping just text.
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Date: Mon, 25 Feb 85 11:14:15 EST
From: Carl Moore (VLD/VMB) <cmoore@Brl-Vld.ARPA>
To: telecom@Brl-Vld.ARPA
Subject: Md. pay phones
I recently saw 25 cent charge for pay phone in Md. suburbs of Washington,
DC. (Prefix 301-577, should also be reachable via area code 202.)
But I still see 20 cent charge on 301-272, Aberdeen. 272 and 577 are
in different LATAs (Baltimore & Washington); could that have effect?
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Date: Monday, 25 Feb 1985 14:19:37-PST
From: goldstein%donjon.DEC@decwrl.ARPA (Fred R. Goldstein)
To: telecom@bbncca.ARPA
Subject: Residential PBX; T-1
Re: the proposal to put in a residential PBX;
A PBX can be used by residential customers, in which case its trunk
lines go at the (low) residential rate. This is sometimes the case
in college dorms, but you must be sure that ONLY residential phones
(dorm lines and not administrative lines) can use the residential
trunks. That means careful classmarking to restrict the non-residential
phones away from residential trunks, and on to business tariff trunks.
It's the "nature of the use" that counts. Hotels are special, and
NOT residential in that sense.
Resale of local trunks is a state option. It used to be taboo, but the
FCC made interstate circuits shareable in the '70s, and many states have
followed on. "Joint User" tariffs apply in some places when a local
line is shared; this typically charged 50% of the line rate for each
additional customer sharing a line.
Crossing a right of way may affect telco rates (it become inter-site)
for lines, and it may require town permission to cross their roads, but
it doesn't make anyone a phone company. If a landlord requires
tenants to purchase telephone service through his resale operation, then
he's treading on thin ice. But making a shared PBX available is generally
okay. Some states are questioning it -- Southwestern Bell is upset by
the idea, but some telcos (Bell Atlantic?) are going in to the business
via their unregulated subsidiaries.
_____
Re: T1 question on last issue;
Common carrier T1 services require that you meet several constraints,
including bits density (10% ones), no more than 15 consecutive zeroes,
and follow standard framing on the 193rd bit. Extended framing is
a future, since the BOCs don't support it yet. ATTCOM wants it, though.
How you format the subchannels is up to you; you don't have to use
24 or 44 channels, but you need to meet the bit restrictions since
that's where the clocking comes from.
A technique called "B8ZS" (bipolar eight zero substitution) overcomes the
consecutive zeroes problem, and permits 192 of 193 bits to be available to
the user. But don't try it here -- it's common in Europe, but North
American telcos don't support it yet in many places. It's described in pub
41451, but most existing T1 carrier equipment predates it.
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End of TELECOM Digest
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