TELECOM Digest Sun, 6 Feb 94 06:29:00 CST Volume 14 : Issue 63

TELECOM Digest Sun, 6 Feb 94 06:29:00 CST Volume 14 : Issue 63

Inside This Issue: Editor: Patrick A. Townson

Time Domain Reflectometers (Mark Earle)
More California / Caller ID Questions (Ethan C. Tuttle)
Can I Request LTN For ANI on All Trunks? (Barton F. Bruce)
Information on Northridge, CA Switch After Earthquake? (Jodi Weber)
Trick to Get Free NYNEX Screening (Barton F. Bruce)
Telecommunications Over Cable Lines (Paul Jonathan E. Go)
NTI Recommendations With Care! (Steve Bauer)
A Cheap Long Distance Service (Allen Walker)
"Miniplex" == Digital Local Loop? (Ray Berry)
For Sale: PBX, Dual Channel Bank, DSX Panel (Paula Toledo)
Request For Cellular Phone Standards (R. Chandrasekar)
Data-Communication on Voice Lines in Bell Atlantic Territory (Ed Lally)
More Information on the Economics of Dial-Back Services (Wolf Paul)
CompuServe's New Rates Effective February 6, 1994 (Ray Normandeau)
Extend-A-Phone (Ray Normandeau)
Looking For Reviews of Routers (Rob Ryan)
Help Wanted With NET2 Test Spec for X25 (Dave McConnell)
Re: Clock Slip and { Once More (Lars Poulsen)
Re: Clock Slip and { Once More (Bill Mayhew)

TELECOM Digest is an electronic journal devoted mostly but not
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Date: Sat, 5 Feb 94 09:11:40 CST
From: [email protected] (Mark Earle)
Subject: Time Domain Reflectometers

Last time I needed one of these, we called a company in Los Angeles,
LeaseMetric. They supply specialized test gear short term; will ship
second day or overnight, etc. Generally, you need a corporate P.O. or
a credit card with a pretty high limit/available credit line.

We used a TDR to verify cables pulled by subcontractors were run with
no splices.

The TDR we used had an o-scope, and a small calibrated dial, and some
"range" buttons. You clip the tdr on the cable under test, and you get
a flat line on the scope. Turn the range knob, until a "bump" appears.
Read the digits on the range knob/range buttons; it is accurate to
about three inches.

Newer versions of the TDR of course do this automatically, and can
even use a laptop as a terminal, storing stuff in a flat file, and
allowing automated test routines to be written using the terminal
program macro language (I've seen this done with Procomm Plus in
particular).

For more general information on TDR's, you might contact Techtronix,
Hitachi, or other "major" vendors of test gear.

Other uses of TDR's: On radio towers, to verify location of splices in
transmission line; to find bullet holes in feedlines. In underground
wires or cables, to find where they "turn" without digging up the
whole landscape, etc. Quite a handy device.

[email protected]

------------------------------

From: [email protected] (Ethan C. Tuttle)
Subject: More California / Caller ID Questions
Date: Sat, 05 Feb 1994 10:19:06 -0800
Organization: Stanford University

I have a technical/political question about CallerID in California:

Say someone calls me long distance from an LEC that supports Caller
ID. My understanding is that the long distance carrier would pass the
Caller ID info to my LEC, which would then forward those digits to my
CallerID equipment. EXCEPT, perhaps, in California. Does the Caller
ID legislation in CA protect the privacy of those outside of the
state? As a Californian, do I get that Caller ID info from
out-of-state callers?

More important, does (or will) PacBell actually forward the Caller
ID info? I don't yet have a Caller ID box to test. I tried to ask
PacBell, but all they seem to know about Caller ID is 'uh, no.'

I am primarily interested in Caller ID as a cheap transport mechanism
for ANI.

Ethan Tuttle

------------------------------

From: [email protected] (Barton F. Bruce)
Subject: Can I Request LTN For ANI on All Trunks?
Date: 5 Feb 94 17:04:18 -0500
Organization: Cambridge Computer Associates, Inc.

The ANI number that the LEC presents to the FG-B trunk when you make a
call need not be the actual physical line you are on (WTN), but may
often be the Listed (LTN) number or possibly the Billing (BTN) number
if they happen to differ for historical reasons.

This seems to happen randomly, but sure would be nice to be able to
ORDER in some standardised way.

Now that many 800 mail order companies make effective use of
recognising your number, it would be nice if all company two way G/S
trunks into the PBX had *JUST* the LTN of xxx.x000 or whatever glamor
number you have.

We have MANY totally scattered numbers in DIFFERENT exchanges in the
same hunt group. Folks at the far end may even have a "REDIAL-THE-LAST-
CALLER" button on their 800 based support phones.

I am having a devil of a time trying to convince telco to give me the
ANI I want (LTN) on trunks I am adding. OTOH, I **KNOW** some folks
out there have gotten telco to do this.

Is there any magic incantation or better USOC code for ordering this?

------------------------------

Date: Sat, 5 Feb 94 16:00:11 EST
From: [email protected]
Subject: Info on Northridge, CA Switch after Earthquake?
Organization: AT&T

I hope I haven't missed this already during the past few weeks, but
I'm interested in any information regarding how badly the Northridge,
CA switch was damaged during the earthquake a few weeks ago, where
service was out, why and for how long.

Apparently, after the quake there was no dial tone for a period of
time, then users had to wait but were able to get dial tone. I'd
appreciate any details on the situation.

By the way, an addendum on the dial tone availability after the quake:
While land lines were dead for some period of time, cellular service
was uninterrupted (at least for one user in Northridge at the time).

Jodi Weber
[email protected] or [email protected]

------------------------------

From: [email protected] (Barton F. Bruce)
Subject: Trick to Get Free NYNEX Screening
Date: 5 Feb 94 17:39:54 -0500
Organization: Cambridge Computer Associates, Inc.

A most interesting bill stuffer from NYNEX just now details a back
door way to get FREE screening to eliminate collect and third party
billing abuse to your number rather than paying their usual 97 cents
per month.

Seems you can now LEGALLY request that they NOT give your name and
address to other carriers if you so request.

Of course they say that if you have their LEC calling card and place
that restriction they will have to CANCEL your card. Seems they can't
just restrict your use to IXCs that just bill via the LEC's billing
service, and so might have to divulge the billing information were you
to use the card with the 'wrong' carrier.

So *IF* I request them to NOT divulge my name , I get my card
cancelled, **AND** I get F R E E collect and third party screening
tossed on the line(s) FREE!

So if you want that service, or are paying for it now, and don't have
KIDS that ever might need to call collect in some emergency, you can
now arrange for free screening by requesting the right set of options.

In my case my kids have their ROA cards that have no CC charges and
are preferred, but they ALSO know the PIN on the all too obvious LEC
card. If there were some accident or whatever, I really WANT them to
be able to use the easy LEC card number or be able to call collect.

But I am sure some other folks would like this new free NYNEX service :-)

[TELECOM Digest Editor's Note: Actually no, telco cannot refuse to
give your name and address to other carriers *for billing purposes
only*, even if you have a non-published number. So go ahead and cancel
your calling card if that is what you wish, but bear in mind that if
someone calls you via a phone subscribed to a carrier who *does not*
check the database used jointly by AT&T/MCI/Sprint and the local Bell
companies, and you accept collect charges, then you *will* get billed
for the call anyway, and the AOS/COCOT firm which originated the call
will get your name, address and phone number. 'Billed Number
Screening' as it is called (where collect and third-party calls are
blocked right on the spot at the time/place of origin) ONLY works when
the database is consulted. Some of the larger carriers (other than the
Big Three who all cooperate on this) maintain their own database also.
For example, Integratel does their own thing and does not consult the
database used by AT&T.

So regardless of what you advise your local telco (acting as billing
and collection agent for the Big Three), unless you call Integratel
and tell them the same thing (and Oncor to name another example) then
the payphones of those companies will still be passing along collect
calls (at outrageous rates I might add!) unchallenged, and your local
telco will bill for them because under the law they have to. Integratel
will add you to their database on behalf of their clients at your request
with no qualms. Its no skin off their nose since all they do is bill
for a bunch of small outfits. PAT]

------------------------------

From: [email protected] (Paul Jonathan E. Go)
Subject: Telecommunications Over Cable Lines
Date: Sat, 5 Feb 1994 17:29:45 PST

In the Philippines, we have a severe shortage of telephone lines. If
one does not bribe someone at the phone company, the wait for a new
phone line is measured in years or decades. However, the cable systems
do not seem to have a backlog.

(1) How are cable networks usually set up?

(a) Are they in a "bus" or "star" topology?

(b) How are signals transmitted? Are they FDMA?

(2) What kind of equipment is needed to turn the cable network into
a telecommunications network?

Could you point out a reference that might answer these questions?

Thanks in advance.

Paul Jonathan E. Go Caltech MSC 1028 Pasadena CA 91126

------------------------------

From: STEVE BAUER <[email protected]>
Subject: NTI Recommendations With Care!
Date: Sat, 5 Feb 94 19:53:35 CST

Jeff,

I am running the NOrthern Telecom Meridian Mail (GP) Voice Mail
system. I have been pleased with the equipment, but can't say that
NTI is an easy company to work with. Forget technical support unless
you have an emergency. It's just not available.

I could write an entire TELECOM Digest on the troubles I have had
trying to get someone to even bid on a maintenance contract and on
parts to upgrade the system.

In a nutshell, the equipment is nice, but the NTI is just too big and
one division does not talk to another.

I will be happy to discuss things in more detail by phone if you would
like.

Steve Telecommunication manager
INTRUST Financial Corporation (316) 383-1144

------------------------------

From: Allen Walker <[email protected]>
Subject: A Cheap Long Distance Service
Date: Sat, 5 Feb 94 23:13:54 -0500
Organization: Delphi ([email protected] email, 800-695-4005 voice)

If anyone is interested, I have found a telco long distance service
that only charges $2.60/hr. Those calls can be placed at any time of
day to anywhere (even your own state) at that rate. There are some
other restrictions. If anyone wants info, send email to [email protected].

[TELECOM Digest Editor's Note: There are so many of these things (notes
about 'cheap long distance') showing up here in the mail each day. It
has gotten almost as bad as 'Make Money Fast'. That one is showing up
fresh on various Usenet newsgroups at the rate of about once every two
weeks now (as the net increases in size so will the number of Make Money
Fast postings; in snail mail I get two or three such chain letters *each
week* in my PO Box), and the 'cheap long distance' resellers are also
all over the place now, and bound to increase in numbers. So, Allen0,
tell us about 'the one you found which charges $2.60 per hour'. How they
manage to do that -- long distance calls day or night, inter/intrastate
at 4.33 cents per minute -- without some deceptive nonsense having to do
with multi-level-marketing or some other gimmick we've read about here
several times in the past -- should make great reading. Tell us about it
here so that you are not bothered with a lot of email, that is unless
you are selling 'what you found' and want the email. PAT]

------------------------------

From: [email protected] (Ray Berry)
Subject: "Miniplex" == digital local loop?
Date: Sat, 5 Feb 1994 13:31:36 -0800
Organization: Ascendant Systems

US West recently installed two numbers in my residence on a single
copper pair. They did this by installing a Raychem "Miniplex 4-in-3
RT", which supposedly muxes two lines onto a single pair by converting
both to a digital data stream, which is deciphered at the CO by a
mating card.

When the installer explained this to me, I became a bit wary about
fax and data signals making it through, but both seem to work fine (at
least for 1 data + 1 simultaneous voice call; I haven't tested it with
two simultaneous data transmissions).

Being a techie type I'd like to know more about this device but
don't know where to ask. Can someone here expound further?

ray berry kb7ht [email protected] [email protected] [email protected]

------------------------------

From: [email protected] (Paula Toledo)
Subject: For Sale: PBX, Dual Channel Bank, DSX Panel
Date: 6 Feb 94 00:17:54 GMT
Organization: The University of British Columbia

3 MSU Redcom
Configured with 28 extensions
8 Ground start circuits
20 DID circuits

Westcom dual channel bank
20 DID cards
8 Ground start cards

25 circuit DSX panel

For more information e-mail Paula at [email protected]

------------------------------

From: News account <[email protected]>
Subject: Request for Cellular Phone Standards
Organization: National Centre for Software Technology, Bombay, India.
Date: Sun, 6 Feb 1994 07:25:38 GMT

Greetings!

A colleague wants to know where standards for Cellular Phones may be
obtained from. He is interested in some standard called US94 or US95,
in particular. Are these available online? If so, where? If not, whom
should one contact to get these standards?

Any info on this would be much appreciated.

May I request you to send your responses by email to:

[email protected]

Thank you,

R Chandrasekar Email: [email protected]
National Centre for Software Technology Fax : +91 (22) 621 0139
Gulmohar Cross Road No. 9 Phone: +91 (22) 620 1606
Juhu, Bombay 400 049, INDIA Telex: +81 (11) 78260 NCST IN

------------------------------

Subject: Data-Communication on Voice Lines in Bell Atlantic Territory
From: [email protected]
Date: Sun, 06 Feb 94 01:28:46 EST
Organization: The Cellar electronic community and public access system

DAVIDSON <[email protected]> writes:

> I don't question the data provided here, but I suggest the "plug" for
> a conditioned line may be overstated. I have found now at two
> locations that a trouble call to 611 has resulted in a visit from a
> repairman who in both instances swapped pairs until he found me a
> quieter one. In one case, this was an internal job at my business
> location and required tracing lines through 4-5 junction boxes in a
> 70+ year old three story building. The repairman came back twice. In
> the other case, it was at my temporary residence, the repairman took
> 10-15 minutes to find a quieter pair and even set-up a new demarc for
> it. I paid nothing in either case to assure reliable 14.4Kbps connections.

I don't know how reliable this is, but both our office phone person
and my modem manufacturer (home use) claim that there's no physical
difference between POTS and data service pairs. They claim that the
only difference is in price (with many local carriers charging a
premium for the data service).

Ed Lally [email protected]

------------------------------

From: [email protected] (Wolf Paul)
Subject: More Information on the Economics of Dial-Back Services
Reply-To: [email protected]
Organization: Alcatel Austria Research Center, Vienna, Austria
Date: Sun, 6 Feb 1994 04:00:16 GMT

After the recent repost here in the Digest of information on
Communications Systems International's Dial-Back service I wrote to
Mr. Beatty and eventually received a DOS program from him which
permits one to select any country of origin and any target country,
and find the rate charged by CSI for a call during any one of three
time periods (11p-8a, 8a-5p, 5p-11p US time, probably Mountain, since
CSI is located in Colorado).

Of course, the most interesting relation to me was Austria-US, and the
prices quoted for that are:

First Minute 1.50 / 1.99 / 1.59
Add'l Minute 1.14 / 1.57 / 1.21

Then I looked into the current phone book to find out what our local
phone company (the Austrian PTT) charges for a call to the U.S.:

AS 18 / minute == $ 1.50

Thus for much of the time, the regular long distance charge is as
cheap or even cheaper than CSI's rate, especially during those hours
when I am likely to reach anyone in the U.S.

Add to that (a) the monthly minimum charge and (b) the inconvenience
of only being able to call from the number where the dial-back box is
going to call you back at, and I begin to wonder if this is such a
good deal at all.

Of course you can forget about using the service to call European,
Middle Eastern or North African countries as well; there are slightly
more substantial savings to be realized when calling countries in
Latin America or the Far East.

But since my need to call these places is rather limited, I guess I
will currently pass on Mr. Beatty's service.

Wolf N. Paul, Computer Center [email protected]
Alcatel Austria Research Center +43-1-391621-122 (w)
Ruthnergasse 1-7 +43-1-391452 (fax)
A-1210 Vienna-Austria/Europe +43-1-2206481 (h)

------------------------------

Subject: CompuServe's New Rates Effective February 6, 1994
From: [email protected] (Ray Normandeau)
Date: 6 Feb 94 00:09:00 GMT
Organization: Invention Factory's BBS - New York City, NY - 212-274-8298v.32bis
Reply-To: [email protected] (Ray Normandeau)

I was wondering if you would save by switching to CompuServe's
$8.95/month membership rather than the $2.50/month membership?

If you use 2400 bps the break-even point is at 50 minutes as can be seen from
the spread sheet results below.

Hourly Meter Monthly
Minutes Hours Rate Total Rate Total

50 .83 $12.50 10.42 2.50 $12.92
50 .83 $4.80 4.00 8.95 $12.95

Ray Normandeau
Normandeau Newswire (J 5) at the Invention Factory BBS, 212-274-8110.

[TELECOM Digest Editor's Note: Could you give us more details about
how the new rate structure works? What are the prices now? PAT]

------------------------------

Subject: Extend-A-Phone
From: [email protected] (Ray Normandeau)
Date: 6 Feb 94 01:49:00 GMT
Organization: Invention Factory's BBS - New York City, NY - 212-274-8298v.32bis
Reply-To: [email protected] (Ray Normandeau)

I have an Extend-A-Phone manufactured in 1981. It is a Model R900
Handheld = c. 49.89 Mhz Base = c. 1.7 Mhz No dial pad.

I was always happy with this phone. I only used it when visiting other
people's apartments. Never needed to dial. The fact that the base at
1.7 Mhz is unlikely to be monitored by anyone is fine with me.

Anyone else have one?

Within the last year or so it stopped functioning.

When I checked battery with a multi-meter voltage seemed to be OK.

Anyone else encounter such a problem and corrected it?

If so, how?

Thanks,

Ray Normandeau
Normandeau Newswire (J 5) at the Invention Factory BBS, 212-274-8110

------------------------------

From: [email protected] (Rob Ryan)
Subject: Looking For Reviews of Routers (Harvard Labs Review)
Date: 5 Feb 1994 17:51:55 -0500
Organization: System Constructs, Inc

I'm looking for the text of a review of routers by Harvard Labs. Does
anyone out there know anything about it? Can anyone point me in the
right direction? If not, then any similar unbiased review of routers.

Thanks.

------------------------------

From: [email protected],
Subject: Help With NET2 Test Spec For X25
Date: 6 Feb 1994 08:27:02 GMT
Organization: Consultancy in Advanced Technology

Hi,

I need to do some qualification testing of an X25 implementation. Our
local telecom company informs me that the NET2 test suite is what is
required to be met but cannot supply me with a test specification
(believe it or not!). They apparently have a machine programmed with
the test suite but don't have the spec itself. Does anybody know where
I could get the Net2 test specification for X25? An ftp sight would be
the best but any info will help.

Thanks,

Dave McConnell ([email protected])

[TELECOM Digest Editor's Note: We have some readers of this Digest at
the telkom.za site. Perhaps someone will respond and help you. PAT]

------------------------------

From: [email protected] (Lars Poulsen)
Subject: Re: Clock Slip and { Once More
Organization: CMC Network Products, Copenhagen DENMARK
Date: Sun, 6 Feb 94 00:00:30 GMT

In article <[email protected]> [email protected] (Mike
Long) writes:

> About two years ago I first ran into the clock slip problem and seeing
> {{{{ on my screen. The problem finally cleared up after ...
> Now I see ^?{ combination rather than {{{{ plus a few interspersed
> random characters.

> Now my question is this: what is it about clock slip that causes a {
> character or 01111011 to appear on my screen? Now it is possible that
> I saw ^?{ before but I only remember the {{{.

> I know what to do about it, I'd just like to understand what is going
> on. I was told before that the clock at the central office could be
> slipping or was left in the wrong mode after a maintenance call.
> Given that, how does the { get to my screen and why { and not some
> other character?

When the asynchronous link is idle, it is sending "mark" bits,
11111111111111111111111111111 .... which the modem encodes into some
other pattern, which gets turned into tones, which get digitized at
the CO and sent over a trunk ....

The clock slip inserts (or drops) a bit in this other, digitized,
bit stream. This causes a temporary difference in the pattern, which
causes a couple of bit errors on the receiving end.
Exactly what comes out depends on:

- which modulation is used (2400, 9600, 14400 ...);
- whether it's a bit insert or a bit delete, and whether the
channel bank dropped a whole frame;
But for a given trunk, these factors tends to be the same.

It is common to see these with 2400 bps. For the last year, I have
been using only V.32bis, and the error correction takes care of the
junk.

Lars Poulsen Internet E-mail: [email protected]
CMC Network Products Phone: (011-) +45-31 49 81 08
Hvidovre Strandvej 72 B Telefax: +45-31 49 83 08
DK-2650 Hvidovre, DENMARK Internets: designed and built while you wait

------------------------------

From: [email protected] (Bill Mayhew)
Subject: Re: Clock Slip and { Once More
Organization: Northeastern Ohio Universities College of Medicine
Date: Sat, 05 Feb 1994 16:48:59 GMT

Modems use a scrambler polynomial which has a 16 bit cylce. This
cyclic stream of 1s and 0s has an even division between the two
values. When a call is placed, the modems sychronize the scrambler
value at both ends, The scrambler data is eclusive-or'ed with the data
at both ends so that under ideal conditions, the input and output data
are identical. The purpose of using the scrambler data is to ensure
an equal distribution between 1 and 0 while the cirucit is in an idle
marking condition while no data are transmitted. This allows the
demodulator at the receiver to stay in track with the other end.

The design of the scrambler circuit ensures that a single bit error in
the transmission will hit two adjacent characters in the output stream
due the way the shift-register is tapped and the fact it is a 16 bit
cycle. The design is no accident, as this assists in spotting
transmission errors -- though I sure wouldn't count on this as
insurance of being able to sptot errors.

For an idle line, the most common error in the direction of the
originate modem is ~r at 1200 bps. At 2400 bps, the most common error
you'll see is _w. If you are using different byte lengths other than
(8N1), you may see something else.

Sure is irriating to have a T1 span dropping frames between you and
the place you want to go. I went around on such a problem with then
Ohio Bell for several years. I'd imagine the upper eschelon of
craftpeople could have been aware of the problem because all the T1
common equpment racks I've seen (which is hardly exhaustive of all
available) have some sort of error lamp or LED that lights up and
stays on when a framing error is received. Ohio Bell eventually fixed
the problem, but didn't respond quickly because the POTS lines I was
using met applicable specifications of the regualting tariff. If I
were buying a conditioned line, things would have been different.
Since we need to support itineratnt users from variable locations,
dedicated lines were not a parctical or inexpensive consideration.
Until the problem was solved, we bought Telebit modems that did not
find the noise bothersome to their PEP protocol.

I have a feeling that all that was necessary was to flip a switch on a
T1 rack somewhere from FREE RUN to LOOP TIMING, but getting somebody
to understand what I wanted and also willing to take action proved
difficult.

Bill Mayhew NEOUCOM Computer Services Department
Rootstown, OH 44272-9995 USA phone: 216-325-2511
[email protected] amateur radio 146.58: N8WED

------------------------------

End of TELECOM Digest V14 #63
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