The World of Computer Software/World_Of_Computer_Software-02-385-Vol-1of3.iso/t/tc13-015.zip/TC13-015.TXT

Text File | 1993-01-09 | 19KB | 424 lines

TELECOM Digest     Thu, 7 Jan 93 16:49:30 CST     Volume 13 : Issue 15

Index To This Issue:                     Moderator: Patrick A. Townson

    Re: All Circuits Are Busy Now ... (Brent Capps)
    Re: All Circuits Are Busy Now ... (Richard McCombs)
    Re: Why Does Phone Bell 'Ping' on a Regular Basis? (Bill Huttig)
    Re: Why Does Phone Bell 'Ping' on a Regular Basis? (Joe Malloy)
    Re: Why Does Phone Bell 'Ping' on a Regular Basis? (Brent Capps)
    Re: Why Does Phone Bell 'Ping' on a Regular Basis? (John Rice)
    Re: Why Does Phone Bell 'Ping' on a Regular Basis? (Troy Frericks)
    Re: Why Does Phone Bell 'Ping' on a Regular Basis? (Fred Schimmel)
    Re: 976 Fraud in Toronto (Daniel Burstein)
    Re: 976 Fraud in Toronto (Jan Steinman)
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From: [e-mail] (Brent Capps)
Subject: Re: All Circuits Are Busy Now ...
Organization: Atlas Telecom Inc.
Date: Thu, 7 Jan 1993 20:03:49 GMT


In article <[e-mail]> [e-mail] (Andy
Sherman) writes:

> On 25 Dec 92 21:26:00 GMT, [e-mail] (John Higdon) said:

>> I would have thought that by now AT&T would have stopped its annoying
>> practice of drastically reducing its capacity on holidays. A number of
>> AT&T employees have told me that for reasons that are not very clear,
>> the company has traditionally blocked off a major amount of the
>> system's capacity on various holidays such as Christmas and Mother's
>> Day. This is the real reason you get the "All Circuits Busy"
>> recording, not because there is an inordinate amount of traffic.

> I can't imagine why they would deliberately turn away business, since
> they make money selling it.  Furthermore, if you go find back issues
> of the {AT&T Technical Journal} in a library, I suspect you will find
> that Mothers' Day is the acid test for new routing algorithms like
> DNHR (Dynamic Non-Hierarchical Routing) and RTNR (Real Time
> Non-Hierarchical Routing).

I strongly suspect that AT&T turned on every traffic throttling tool
in their arsenal.  That's why they're there -- to keep the switch from
being overwhelmed by the number of origination attempts.  Remember,
switches have limited internal resources -- call control buffers,
interprocess communications mechanisms, timing-critical events -- that
start breaking down when the switch gets really, really busy.  If,
say, a given interprocess communications channel gets choked with
messages, internal watchdog processes may conclude that part of the
system is stuck and deliberately swap the switch to the standby CPU,
which of course will quickly get overwhelmed and lock up.  So to
prevent this they turn on a throttling feature like LLC (line load
control) which will only give you dial tone on, say, 1 out of every 10
origination attempts.

> On 27 Dec 92 09:24:00 GMT, [e-mail] (John Higdon) said:

>> How soon we forget. Hours after the 1989 Loma Prieta earthquake, I
>> tried at some length to get though to my home from southern
>> California.  All circuits were busy. Then I tried Sprint. The call
>> went right through. Discussions right here on the Digest pointed to
>> the policy of AT&T of purposely restricting incoming access to a
>> disaster area. I, for one, was very grateful for the fact that AT&T's
>> policies are not always imitated by the competitors.

> The choke after the earthquake had a reason behind it.  It was to
> reserve some large fraction of trunk capacity for outgoing calls from
> the disaster area.  That policy and the reason for it was plastered
> all over the media, in hopes that people would wait for the "I'm OK"
> call rather than flooding the network with call attempts to empty
> houses.  I believe that the disaster assistance agencies also liked
> that arrangement, since it improved the chances of their folks on the
> scene being able to call out.

This should hardly have come as a surprise to anyone.  Disaster
planning agencies publicised this fact beforehand, and I made
arrangements with all my loved ones in the state to call a mutual
friend in Texas who would relay messages and act as a kind of
information clearing house.  When the '89 quake hit I was in Los Gatos
not far from the epicenter and was able to communicate with my husband
in San Francisco because we could both call Dallas and leave messages
for each other.  You couldn't get through to San Francisco from Los
Gatos for several hours after the quake.  All in all I thought AT&T
and Pac Tel did a fine job.  After all, the power wasn't back on in
Los Gatos until the next afternoon, but the phones were working within
15 minutes, and I don't know if they ever actually went down.

As an aside, I was working for T1 mux manufacturer DCA/Cohesive at the
time, and literally hundreds of these big (6' tall) mux cabinets were
rolling around the test lab and mfg area like loose cannons.
Engineers were scrambling like mad to keep from being crushed.  We had
a bunch of $5000 Fireberd T1 testers stacked precariously six high on
top of one cabinet, and it's a miracle they didn't fall over.
Ironically our customers were required to bolt their muxes to the
floor instead of standing them on their castors like ours were, but
one customer's mux fell *through* the floor, so bolting it down didn't
do them much good.  Fortunately, nobody got hurt at our site.

I was in Oregon working for Kentrox on T1 CSUs within two months.
That quake was the last straw for living in California.


Brent Capps   [e-mail] (gay stuff)
[e-mail] (telecom stuff)

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Subject: Re: All Circuits Are Busy Now ...
From: [e-mail] (Richard McCombs KB5SNF)
Date: Thu, 7 Jan 93 14:26:18 CST
Organization: The Red Headed League; Lawton, Ok


In comp.dcom.telecom, [e-mail] (and other in similar
words) writes:

> Or, take a lesser used route (MCI or Sprint).  For the future, the

Well I distinctly remember having trouble calling from Lawton, OK to
Fort Worth, TX using MCI, so they get saturated to.


Internet: [e-mail]
If I bounce (the maps have errors that I have no control over) then use
[e-mail]   BITNET: bo836%cleveland.freenet.edu@cunyvm

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

Date: Thu, 7 Jan 93 11:49:04 -0500
From: [e-mail] (Bill Huttig)
Subject: Re: Why Does Phone Bell 'Ping' on a Regular Basis


   The answer -- at least one possible answer -- is that the phone
company runs line tests every day at about the same time ... (The same
thing happed to me but at 6:20 AM and would wake me up) ... I don't
remember why but I ended up buying (about $4 at Radio Shack) a
polarity phone line tester; it should the polarity was reversed. Then
all I had to do was to change the red and green wire around in the
jack and I didn't have anymore pings.


Bill

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

From: Laura G. Malloy <[e-mail]>
Subject: Re: Why Does Phone Bell 'Ping' on a Regular Basis?
Organization: Bates College, Lewiston, Maine
Date: Thu, 7 Jan 1993 08:14:17 GMT


In article <[e-mail]> [e-mail]
(Glenn F. Leavell) writes:

> It seems that I've seen discussion on the following topic in the
> TELECOM Digest before, but I can't remember the answer or find
> anything relevant in the archive index.

> My parents live in Mississippi and get their local phone service from
> South Central Bell.  According to my parents, the bells in their
> phones make a 'ping' every evening around 10:15PM.  They say that the
> ping almost always occurs around the same time, but that on certain
> nights it may not occur until close to midnight.  They've called South
> Central Bell about this, and they were told that the ping was NOT
> occuring due to anything that the phone company was doing.

[deletia]

Same thing happens to us in Clinton, NY, each evening (sometimes
weekends, too) at just about 11 PM.  I've always assumed some sort of
telco testing was going on, but it would be nice to know exactly what
they are doing!


Joe Malloy/WB2RBA    German Department/Hamilton College/Clinton, NY

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

From: [e-mail] (Brent Capps)
Subject: Re: Why Does Phone Bell 'Ping' on a Regular Basis?
Organization: Atlas Telecom Inc.
Date: Thu, 7 Jan 1993 19:04:22 GMT


In article <[e-mail]> [e-mail]
(Glenn F. Leavell) writes:

> According to my parents, the bells in their phones make a 'ping'

every evening around 10:15PM.

SSB is pulling your leg.  Your CO switch is running automatically
scheduled self-diagnostics.  They start every evening at the same
time, but they're really testing the line cards and not the lines, so
only one line per card gets 'pinged', typically the first one.  I used
to have a line in Dallas that would ping every evening at 8:15 PM.


Brent Capps | [e-mail] (gay stuff)
[e-mail] (telecom stuff)

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

From: [e-mail]
Subject: Re: Why Does Phone Bell 'Ping' on a Regular Basis?
Organization: Teradyne Inc., Telecommunications Division
Date: Thu, 07 Jan 93 21:00:32 GMT


In article <[e-mail]>, [e-mail]
(Glenn F. Leavell) writes:

> My parents live in Mississippi and get their local phone service from
> South Central Bell.  According to my parents, the bells in their
> phones make a 'ping' every evening around 10:15PM.  They say that the
> ping almost always occurs around the same time, but that on certain
> nights it may not occur until close to midnight.  They've called South
> Central Bell about this, and they were told that the ping was NOT
> occuring due to anything that the phone company was doing.

This, not uncommon, occurrance is caused by automated line test
equipment. The real clue is the fact that it happens every night at
about the same time.In SCB it's probably MLT or MLT2. This equipment
can be set up to routinely test each line in an office, every night on
a regular schedule.

The phenomena is known as 'bell tap'. When the line is tested, it is
disconnected from the line finder, or line circuit, which provides
dial tone, for the one or two seconds that it takes to perform the
parametric measurements on the line. These tests are usually done at
low voltage (10-20v) and won't usually cause a phone to ring.

When the line is re-connected to the line circuit, -50v is placed back
on the line. The 50v is sometimes enough to cause the ringer magnet to
pull the clapper against the bell, one time. Also in some of the
'cheepie' phones with electronic ringers, the sounder will 'cheep'
once when voltage in initially applied (re-applied).

One solution to the problem is to reverse tip and ring on the phone
(reverse the red and green wires at the connector block.  This causes
the magnet to kick the clapper the opposite direction when voltage is
initially applied.  This will usually work, but if the phone is an
older touch tone phone, this may cause the T.T. Pad not to work (they
were polarity sensitive in older Bell Phones).

Also, it's sometimes possible to mechanically adjust the bell, so that
the -50v pluse isn't quite enough to pull the bell magnet enough to
cause a tap.

With the advent of automated line test equipment in the past 15 years
or so, this has been an on-going problem. It's much more prevalent in
Europe, where telephone instruments are of generally higher impeedance
and it takes much less voltage to ring the phone.

On the other side of the equation, the automated testing allows the
telco to recognize deteriorating outside plant cable in many cases
before the customer even recoginzes that there's a problem, and fix
it. Often out of service lines are reported by the equipment and
repaired with the customer never being aware of a problem.  A
deteriorating cable or cross connect box that could ultimately result
in 20-50 subscriber trouble reports can often be found, diagnosed, and
repaired before any customer reports occur, so that grade of services
is improved overall. (And it's less expensive to do it that way then
respond individually to each and every call as they occur), thus
everybody saves.


John Rice        K9IJ     |  "Did I say that ?" I must have, but It was
                          |   MY opinion only, no one else's...Especially
                          |   Not my Employer's....
[e-mail]     |   Purveyor of Miracles,Magic and Sleight-of-hand

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

From: [e-mail] (Troy Frericks)
Subject: Re: Why Does Phone Bell 'Ping' on a Regular Basis?
Organization: Microware Systems Corp., Des Moines, Iowa
Date: Thu, 7 Jan 1993 20:18:19 GMT


In article <[e-mail]> [e-mail] (Glenn F. Leavell) writes:

> My parents live in Mississippi and get their local phone service from
> South Central Bell.  According to my parents, the bells in their
> phones make a 'ping' every evening around 10:15PM.  They say that the

Have you tried swapping out the phone?  This would rule out some
things like EMI being picked up from something like a water softner or
a lamp on a timmer.  Some cheap (cherp, cherp) phones tend to be less
tolerant than others.


Troy Frericks                      Internet: [e-mail]
Microware Systems Corporation          UUCP: uunet!mcrware!troyf
1900 NW 114th St                      Phone: [phone]
Des Moines, IA 50325-7077               Fax: [phone]

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

From: [e-mail] (Fred Schimmel)
Subject: Re: Why Does Phone Bell 'Ping' on a Regular Basis?
Organization: Gandalf Data Ltd.
Date: Thu, 7 Jan 1993 17:42:11 GMT


It used to be that there was something called a line integrity test
(LIT) that occured in the interval just before the ring cycle began.
The circuit was re-arranged to test the line between the CO and the
phone. This is one reason why Customer Premises Equipment (CPE) needs
to identify its Ringer Equivalence Number (REN) because the test had
differing results depending on the number of ringers on the line.
Perhaps you added or removed some phones, modems, answering machines,
etc. Perhaps your local CO routinely at 10:15PM does a maintenance
check of all its lines, and this is when the ping occurs. Try calling
and asking for a test supervisor to see if they do something like
this.  Or count your equipment total REN and inform the phone company.
It could just be a misprogrammed test, or an indicator that the line
is faulty.

Perhaps someone else remembers more about LIT. I believe this was a #5
crossbar feature.


Fred Schimmel    Gandalf Data Ltd.  [e-mail]

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

From: [e-mail] (Daniel Burstein)
Subject: Re: 976 Fraud in Toronto
Organization: Panix, NYC
Date: Thu, 7 Jan 1993 02:35:24 GMT


In <[e-mail]> Tony Harminc <[e-mail]> writes:

> This past November, a company I consult for had three unauthorized
> calls to [phone] made on one of its lines.  Each call was one
> minute long and was billed at $24.  Thinking back, we remember the
> likely perpetrator -- a man claiming to be serving legal papers on
> someone who supposedly used to work at the office address.  There were
> several small discrepancies to his story, but he seemed just as
> puzzled as we were.  He asked to use the phone, and I remember that he
> did a lot of dialing, but when challenged he showed a pager with
> display and claimed he was calling his voicemail.

> Bell Canada has agreed to remove the charges, but will not tell us the
> name of the owner of this number.  We are not eager to pursue it with
> the police, because of the small amount of the fraud, but we are
> concerned that this may be part of an organized scam (else how would
> the 'process server' benefit?) and others may also have been hit.  The
> $24 charge is quite a bit higher than the usual sex and sleaze lines
> which -- according to the ads -- are mostly $10.

A similar scam has been going on in New York City. A messenger will
show up at a company with a package, and when no one there seems to
match the addressee, he asks to use the phone.  Calls a "540" exchange
(one of the extra charge numbers; the others are 550, 970, 976, and
another about to be announced) and the company gets billed for $50 or
so.

When people notice it on the bill and complain, the local telco wipes
the charge.  But how many people don't ...

Which brings up a question or two about this whole concept of
surcharged phone numbers: Aside from all the legal questions (I'd love
someone to push a strong lawsuit about misbilling and all sorts of
other things), I'd like to know the following:

Does anybody out here have any sort of breakdwon as to the users, or
rather, providors, of these services?


Thanks,

danny  <[e-mail]>

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

From: [e-mail] (Jan Steinman)

Subject: Re: 976 Fraud in Toronto
Reply-To: [e-mail]
Organization: Ascom Hasler AG
Date: Thu, 7 Jan 1993 12:08:43 GMT


In article [e-mail], Tony Harminc <[e-mail]> () writes:

> This past November, a company I consult for had three unauthorized
> calls to [phone] made on one of its lines.  Each call was one
> minute long and was billed at $24.  Thinking back, we remember the
> likely perpetrator -- a man claiming to be serving legal papers on
> someone who supposedly used to work at the office address.  There were
> several small discrepancies to his story, but he seemed just as
> puzzled as we were.  He asked to use the phone, and I remember that he
> did a lot of dialing, but when challenged he showed a pager with
> display and claimed he was calling his voicemail.

This sounds like a scam I heard about from a client in New York City.
It is simple to do, given the right information. All you need is a
bunch of numbers of pagers that display a number to call. Call those
pagers, and give the 976 number to call. The process server may have
been an unwitting victim of this hoax.

For whatever reason, my client assigned pagers to virtually all their
staff, and the numbers were sequential. The hoax was discovered one
day when every beeper in the whole joint began ringing, and people
compared numbers and discovered they were the same number. This was
not too long ago -- not everyone recognizes the significance of 976,
especially when it is in the form of a generally important interrupt,
like your pager going off!


Jan Steinman, Bytesmiths            [e-mail]
2002 Parkside Court, West Linn, OR 97068-2767 USA    [phone]
Beundenfeldstrasse 35, CH-3013, Bern, Switzerland    [phone]

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End of TELECOM Digest V13 #15
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