
From telecom-request@delta.eecs.nwu.edu  Tue Sep 19 22:23:53 1995
by
1995
22:23:53 -0400
telecomlist-outbound; Tue, 19 Sep 1995 17:49:08 -0500
1995
17:49:06 -0500
To: telecom@eecs.nwu.edu


TELECOM Digest     Tue, 19 Sep 95 17:49:00 CDT    Volume 15 : Issue 391

Inside This Issue:                           Editor: Patrick A. Townson

    Re: Variable Length Phone Numbers (Juergen Ziegler)
    Re: Variable Length Phone Numbers (David H. Close)
    Voice Compression on T1s (Jim McGrath)
    Erlang Traffic Engineering Software (Rob Clark)
    Wanted: Fixed Network Planning Tools (Martien Kuunders)
    Re: War on Payphones (Paul Buder)
    Re: War on Payphones (David Adrian)
    Re: War on Payphones (Edmund C. Hack)
    Re: War on Payphones (Maurice R. Baker)
    Evidence for Switching LD Carriers (Larry Rubin)
    Modem Bridging (Christopher Rupnik)
    Gladwin COCOT Documentation Wanted (Matt Bancroft)
    Re: 1-800-555-1212 Blocking at State University Illegal? (John 
Romano)
    New Developments in AOL/FBI Case (John Sullivan)

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



Christian Weisgerber (naddy@mips.pfalz.de) wrote:

> Recently, comp.dcom.telecom has seen some talk on the viability of
> variable length phone numbers within a country (or any specific
> network, for that matter). Many posters, especially those from North
> America, insist on their belief that phone numbers have to be of
> constant length, otherwise one must have timeouts etc.

> First, let me state that I see *no reason whatsoever* why there can't 
be
> variable length phone numbers or why a switch would have to know the
> total length of the number. If you think there is a need for such
> restrictions, please explain why you think so. Your reasons are not
> obvious.

Well, you are right. But I think this discussion is rather technical.
Besides the different requirements for the signalling systems between
a fixed lenght and a variable lenght numbering system, there are
obvious reasons in favour of a fixed length numbering system.

If you want to implement a fixed length numbering system in a network,
then you have to take serious precautions in your design of the system
into account. So in fact, you have to think quite seriously about the
future number demand and other developments, that are crucial to the
design of such a numbering system. A variable lenght numbering system
on the other hand, does not require such emphasis on those
considerations. Well, you just start to assign numbers, and if the
available numbering space is completely used, then you have to do
changes to the current numbers. In Germany this is usually done by
adding some digits to a current number. Such changes usually create
additional cost to the network operator, and the subscribers dont like
such changes at all. Therefore a fixed length numbering system has
major advantages as the need to change any numbers is rather low.

Then, in the long term, fixed length numbering system tend to have
shorter numbers in average than variable length numbering systems.
This is true for Germany. Germany in fact has a total population of 80
millions, and there are 11 digit numbers in use. Well, those long
numbers are still rather seldom to find, but Telekom seems to use such
long numbers nowadays on a regular bases. On the other side, the world
zone 1, which incorporates the USA, Canada and some Caribbean
countries, has just 10 digit phone numbers.  But the world zone 1 has
a total population of nearly 300 millions.  Therefore it should be
asked, how such a large population can be served using just 10 digit
numbers, wheras on the other hand, Germany with a significantly
smaller population needs 11 digit numbers in some places?

I think the answer is rather simple. As I stated earlier, there is no
need to define such a numbering system rather precisely. Instead you
may add and add and add digits to accomodate the "need" of local
numbers. But as there is no general outline or design structure
available, such systems tend to use the theoretcial numbering space
quite inefficiently. Local aministrations will usually start to assign
short numbers. And if it will become obvious, that such short numbers
will not suffice the upcoming demand, then you have to introduce
longer numbers. And whats even worse, most German local numbers are
not just rather short, they are in fact way too short! The German city
of Karlsruhe has a population of around 200'000.  If you consider a
large number of businesses that have a high demand for DID numbers,
then the minimum length should be 6 digits. Well, but in that city
there are also 5 digit numbers. And on the other side, Telekom has
also assigned 7 and 8 digits numbers. If you add the local area code
to such a 8 digit number, then you end up with 11 digits, which does
not include the leading 0 to initiate an area code prefixed call. So
if you want to reach someone in Karlsruhe, then you may have to dial
more digits, than to reach any subscriber in a large US metro area.

One of the reasons for this inefficient use of phone numbers are DID
numbers. Most companies in Germany have DID lines. If you want to
reach the extension 123 you could dial 6454-123. But if you want to
reach the company's operator then you just dial 6454-0. As a result of
this -0 number, you "waste" 99 phone numbers. If you do this rather
often, then you will even waste hundreds of millions of phone numbers.

Another major design flaw of variable length phone numbers that will
become obvious is the introduction of different long distance and
local networks.  This design flaw aroses from the fact, that local
numbers have no "structure" or no structure that can be easily
predicted. But this will become neccessary to allow in local networks
an efficient routing. The way this is done in the USA is rather
simple. Any local network operator can get portions of 10'000 phone
numbers. Such a portion consists of a 3 digit prefix and 4 digit
numbering space from 0000 to 9999. For the routing the fixed length of
the prefix will work extremely well, as you may add any number of such
prefixes to a routing table, even if those prefixes are used
"chaotic". So a nearly unlimited number of local operators may get
such a compact portion of phone numbers. This allows an efficient
distribution of phone numbers, and there is a single and simple
routing possible, as the number of significant digits for the routing
in a phone number is limited to 3 digits.

But fixed length phone numbers have also a very obvious advantage for
the subscribers. Because you always know, if a number is complete or
not. In a variable length numbering system, you will never be able to
tell, if the number is complete, as within the country, or even within
a city, there are shorter or longer numbers in use.

For me it seems obvious that in the long run, all major countries will
implement fixed length numbering systems.


Juergen Ziegler * juergen@jojo.sub.de * 77815 Buehl (Baden) * Germany

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



lincmad@netcom.com (Linc Madison) writes:

> Within the North American phone system, telephone numbers must be of 
an
> easily predictable length.

There are quite a few variable-length phone numbers presently in use
in North America. These are found in automated attendant systems which
prompt a caller to enter the extension of the person desired. The
difficulty is, of course, that the additional digits cannot be entered
until the call is answered and the automaton is ready.

What would it take for an originating switch to accept digits beyond 
those
it figures are necessary to complete the call, buffer them, and then
transmit them after the call is supervised? If the called party was not
an automaton, the tones might be slightly annoying to a human, but not
an insurmountable obstacle. If the caller didn't enter extra digits when
they were needed, he would still be prompted as today.

Wouldn't a scheme like this make it possible to effectively move to
variable-length numbers without a need to alter the fundamental 
character-
istics of the system? Later, after everyone got used to the new 
technique,
real variable-length numbers could be introduced transparently.

Of course, companies which advertise vanity numbers of more than seven
characters might have some problems...


Dave Close, Compata, Costa Mesa CA "Politics is the business of getting
dave@compata.com, +1 714 434 7359  power and privilege without
dhclose@alumni.caltech.edu   possessing merit." - P. J. O'Rourke

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



I would like to hear from anyone with experience using voice
compression techniques in T1 muxes. I need as much of the bandwidth of
my T1s as possible for data, but had to cost-justify the T1s by
including reductions in voice telco expenses. I will probably be using
Newbridge muxes (3600 & 3624), which seem to support a voice-path at
as low as 8kbps. Although it leaves more for data, I'm concerned about
degraded quality. Of 8, 16 or 32kbps, I'm sure 32 is the least
objectionable for the telemarketing people who will be on the phones,
but what kind of quality might I expect?  Are there other mux vendors
who provide better quality at low bandwidths?


mark

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



Anyone interested in finding some software to do Erlang
type traffic engineering calculations?

If so - please checkout http://www.iinet.net.au/~clark


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



I'm trying to get an overview of the fixed telecom network planning
tools which are on the market.  These are tools (generally PC or
workstation based) which, given certain traffic needs, costs, and
other restrictions, determine (semi)automatically the number of
switches needed, positions of the switches, and transmission capacity
needed between the switches.

If you know the names and/or the suppliers of such tools, I'd
appreciate it if you'd let me know.


M. Kuunders, m.m.l.kuunders@research.ptt.nl, +31-703326049 ICBM 52.05N 
4.24E-
KPN Research, P.O. Box 421, 2260 AK  Leidschendam, The Netherlands ------
----

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



In <telecom15.380.6@eecs.nwu.edu> coyne@thing1.cc.utexas.edu writes:

> What difference does it make to drug dealers whether or not they can
> use the key pad?  I am not a drug dealer myself, and I do not have any
> friends in that trade, but I am quite curious about this.

For pagers.  The dealers don't need them, their customers do.  They
dial the dealer's pager and the dealer calls them back.  And your
average street junkie probably isn't going to Radio Shaft to buy a
tone device -- at least until that becomes the only way to make the
call.


paulb@teleport.COM  Not affiliated with teleport.

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



In article <telecom15.380.6@eecs.nwu.edu>, coyne@thing1.cc.utexas.edu 
says:

> What is there in the basic procedure of dealing drugs as practiced in
> high crime or any other area that makes it telecommunication
> dependent?  I can see that you have to have a phone for carriage trade

[...]
> vital to their trade?  Somebody please enlighten me.

Okay, since you asked nicely -- Pagers.


adrian

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



In article <telecom15.380.6@eecs.nwu.edu>,  <coyne@thing1.cc.utexas.edu>
wrote:

> In article <telecom15.374.5@eecs.nwu.edu> henry@q.com (henry mensch) 
writes:

>>> I called the telco to complain and they explained to me that this 
was
>>> done purposely because that telephone is in "a high-crime area".  So

> This attribution looks wrong, but it does not matter.

> What difference does it make to drug dealers whether or not they can
> use the key pad?  I am not a drug dealer myself, and I do not have any
> friends in that trade, but I am quite curious about this.
 
> What is there in the basic procedure of dealing drugs as practiced in
> high crime or any other area that makes it telecommunication
> dependent? 

The drug and prostitution trade is heavily dependent on the use of
pagers and cell phones. For example, if you call your local dealer,
Bill, for a delivery, he pages a runner to make the delivery. The
runner, who may be a juvenile (won't do time that way), picks up the
drugs, makes the delivery and returns with the cash. Or he may just
make the delivery to an intermediary who then delivers to you. Again,
all this is coordinated via pagers and/or cell phones. In the sex
trade, if you call an "escort service" or a "nude maid service", the
dispatcher calls a girl in via pager. If you make a streetcorner deal
with a pimp, he coordinates his men or women via pagers.

Here in Houston, the "war on payphones" has taken two tacks. At some
locations (mainly convenience stores) the payphones are disabled at
night.  At other locations, the payphones are blocked from calling
pager and/or cellular phone exchanges. Since they started doing this,
I haven't noticed a great decrease in the drug or sex for pay trade,
but it sure makes the Telco and the Stop-N-Rob corporations look as if
they are doing something.


Edmund Hack   echack@crl.com   Houston, TX   

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



> What difference does it make to drug dealers whether or not they can
> use the key pad?  I am not a drug dealer myself, and I do not have any
> friends in that trade, but I am quite curious about this.

I suspect that one big use is to interact with paging services, in
order to activate their cohort's pagers/display a callback number/etc.



    


[TELECOM Digest Editor's Note: I have a pager here from Mobile Comm,
which is a Bell South Company. It is the brand being sold by Radio
Shack in this part of the country at the present time. Although you can
use a touch tone phone to send a message to the display window, you
can also just use it as a signal for an answering machine. If someone
calls from a rotary phone or a phone where the touch tones have been
disabled, all they need to do is dial the number and leave a message
anyway. In that case, the pager shows its own number in the display.
So, it requires an extra phone call: one to call voicemail and see who
left the message and a second call to the actual person calling. I
don't think that would be any big extra problem for a drug dealer.  PAT]

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



I am trying to find out what is considered ample evidence that the LD 
company has authorization to switch someone's LD service to them.

I get a lot of calls from LD carriers wanting to switch my service,
and they say they can do it over the phone, that there is nothing to
sign. Do they record these calls?

What steps do they take to protect themselves against accusations of 
slamming?


Larry Rubin    larry@access.digex.net
N3QGH          +1-500-OSSUARY


[TELECOM Digest Editor's Note: I think their rate of return for 
legitimate
orders versus slamming accusations is good enough they don't care if a
few bogus orders go through now and then. They are far more interested 
in making it as easy as possible for new customers who want to use their
service than they are in protecting the rights of customers of other
services slammed in error. If they get hundreds of new customers over 
some
period of time via phone call solicitation versus a couple of bad ones,
its easier to settle with the bad ones. 

Remember the door-to-door encyclopedia salesmen of years ago? Are they
still around?  They had lists of which people in the community had
school age children, and they tended to work in poorer, rural 
communities.
As a sample, they had the *one* volume of their crummy twenty-five
volume encyclopedia which had a picture in it; a nice glossy photo of
President Roosevelt. They went door to door taking orders with their
gimmick being you were selected by the publishers to get the entire 
encyclopedia for free; all you have to do is purchase the annual
updates for the next ten years. If you said you would take the free
enclycopedia but were not interested in the updates then the salesman
'questioned' whether or not he wanted to leave such valuable books at
the home of someone who 'did not care enough' to keep them up to date.
They appealed to very poor minority parents who in all fairness wanted
the best education for their children they could have. 

Needless to say, plenty of poor, uneducated people fell for the gimmick
and signed papers committing to how much they would pay each month on
the annual updates, which after ten years came to *four times* the
price of a good, recognized encyclopedia set. The set of books would
show up by parcel post a few days later and the paperwork was sent to
Chicago where it was processed by 'the loan company which lent you the
money to purchase the books for your children'. The first thing the
'loan company' did was verify the order. You see, the door-do-door
sales people were these young guys -- social dropouts for the most part -
-
who were not above lying and misrepresenting the product they were
selling. And the 'loan company' had a woman do the verifying who taped
the entire conversation. Originally they had not done that but the
stinks to the Federal Trade Commission and others got so bad about
door-to-door salespeople in general (this was 1950-60's) that the
FTC and other government agencies cracked down hard. They made all the
'acceptance companies' (that is, the companies which forwarded the
money to the salesmen then tried to collect it from the salesmen's
customer/suckers) *prove without a doubt* that their orders were
legal and in fact existed. 

The verifier was completely honest, although deceptive in her choice
of words. She told the people she was calling to verify their decision
to 'accept the wonderful free gift the publisher was making available
to school children in the community' and how much it would cost each
month for the 'free gift'. She told them she was tape recording the
conversation, and asked their approval to do so (which was also on
the tape.) Remember, she was speaking with awfully dumb people to 
begin with. At the close of the verification conversation she would
thank them 'for allowing me to tape record this as we have been
speaking so there will not be any errors in the way your order is
handled.'

And six months or so later, when the order invariably went to the
loan company's collection agency (same people just wearing different
hats and using other phone lines) the recipients of the free 
encyclopedia
would insist they did not know why they were getting letters and phone
calls from collectors for a 'loan company in Chicago' that 'we don't
owe any money to.' Meanwhile, the salesmen were busy selling their
books at another town somewhere, staying in a sleazy motel for a few
days while they milked all the suckers there before moving on.   PAT]

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



Is it possible to bridge using modems?

I would like to be able to bridge netbeui/appletalk/ipxspx and tcp/ip
over a normal modem line.  I currently use ISDN lines and Ascend
Pipeline 50's to do this, but of course this is a bit expensive. Is
there any software that will allow me to do that?


Thanks,

Chris Rupnik    chrisr@speedware.com
Speedware Corp. 514-337-5007

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



Where can I obtain programming instructions for a Gladwin Customer
Owned Coin Operated Telephone model number G05225. The phone has a
manufacture date of September, 1985. The last adress I can find for
Gladwin is:

Gladwin
Old Oakwood Rd.
Oakwood, Georgia 30566
(404)536-6023

Neither the above telphone number or address appear to be valid.


Matt Bancroft     bancroft@cis.umassd.edu


[TELECOM Digest Editor's Note: As I recall, that paticular model was
one of the first in their series. Programming was rather easy. You
take the modular cord that normally plugs into the phone line and you
plug it into an AC electric line instead for five minutes. This allows
the circuit board to get properly burned in so you can then install
the new code ... when you see a little bit of smoke start to come up 
from 
the circuit board and a peculiar odor is in the air then you know the
circuit board has been properly modified. Now you take it outside your
house, probably in an alley somewhere and you set it down and walk away.
Come back in a couple days and if it is still sitting there and has
not been too badly cannibalized or de-gutted by junk collectors who
walk through alleys at night looking in trash cans then it should be
ready for use.  grin ... I don't know where those people are now located
and I am not sure I would tell you if I did!  Those are the devil's
instruments if ever I saw any!   Maybe some reader knows something.  
PAT]

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



tedwards@Glue.umd.edu (Thomas Grant Edwards) wrote:

> University of Maryland College Park currently blocks 1-800-555-1212.
> Some students have claimed that this is illegal, is this true?

Unless the routing was changed in the past two months, 800-555-1212
should not be blocked from student phones (I went to great pains to
program the campus PBXs to not block this number).  There will be some
phones it will not work from: courtesy phones, etc. that are restricted
to campus only calling.

As far as whether its 'illegal' or not; the University, because it is
considered an 'aggegator' by FCC ruling, had to open equal access for
dorm resident phones.  For those phones it might be ... for other
phones provided for University employees I doubt its any more illegal
than it is for any other company to restrict access to certain numbers.


John Romano   Telecommunications Engineer
JHU/Applied Physics Laboratory
Eyes:  smiley@aplcomm.jhuapl.edu
Ears:  (301) 953-6061     :-)

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



I now have copies of two of the criminal complaints filed against AOL
users arrested in the operation.  Granted, this is only two cases out
of 12 arrests and a lot of search warrants.  However, neither mentions
AOL monitoring mail or listening in on chat rooms.

In one case actual files, NOT random unwarranted assertions, were 
forwarded to the FBI by a confidential informant.  The complaint 
describes this person as a "concerned citizen" who has been cooperating 
with the FBI for about 12 months and makes it clear that he or she is 
not 
a suspect in any criminal matter.  There is certainly no shortage of 
such 
concerned citizens who would be willing to forward things they came 
across to authorities.  Several of them testified before Congress when 
they were doing hearings on the CDA and the Dole/Grassley Bill.  One had 
been collecting images and reporting the senders to AOL for quite some 
time and was frustrated that no action seemed to be taking place.  I 
have 
no difficulty whatsoever believing that this individual would gladly 
collect information for an FBI operation designed to put it to a stop.

In the other case, the images were obtained by an FBI agent who went 
into 
a chat room posing as a 15 year old boy and had images sent to him 
directly from the suspect.

In both cases, the only mentioned involvement on the part of AOL is that 
AOL under subpoena, gave the FBI the user profile of the two screen 
names.  This included the actual name of the account holder, his AOL 
account number, account status, mailing address and telephone numbers, 
and other screen names associated with that account.

The FBI went on to check telephone records to confirm that calls were 
being placed from the suspect's phone number to AOL dialup numbers, as 
well as other odd bits of data.  In one case they confirmed what kind of 
car the suspect drove in some way that wasn't mentioned.  They also 
checked install dates for telephone and electric service - presumably to 
prove that the AOL profile information was correct before obtaining 
search warrants.

Say what you will about any of this, but it seems clear that AOL was 
involved as little as possible, responding to subpoenas with information 
which was not derived from monitoring of protected communications.  Nor 
is there any evidence of an AOL "enemies list" of suspected child 
pornographers.

More may come to light as other filings become available, but for now 
(gall me though it may to defend AOL) it seems clear that Pat's take on 
what happened is not supported by the facts.


John Sullivan   contributing editor
Internet Week   sullivan@interramp.com


[TELECOM Digest Editor's Note: Would you mind sharing those criminal
complaints with us?  Are they by chance about the two fellows here in
this area who were among the twelve charged?  I know it will be a lot
of typing unless you can scan it in, but I am sure readers would like
to see them.  Thanks.    PAT]

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

End of TELECOM Digest V15 #391
******************************

                                                             
