TELECOM Digest Thu, 24 Mar 94 11:06:00 CST Volume 14 : Issue 145
Inside This Issue: Editor: Patrick A. Townson
Frequently Asked Questions About Caller-ID (A. Padgett Peterson)
CATV Modems (Dominique Gabioud)
FCC Gopher Service (Robert Keller via Peter M. Weiss)
Re: Country Code For San Marino (Carl Moore)
Re: Country Code For San Marino (Bob Smeets)
Information Wanted on Women and Telecom (Melanie Spencer)
Request For Info: Strategic Planning For Local Exchange Carrier (J.
Lovell)
Re: Please Explain the Term 'Steaming Terminal' (David McCord)
Re: Who Paid For My 550? (Terry Gilson)
Re: Area Code 562 (Dave Niebuhr)
Re: Telecom Business Idea (Jonathan Welch)
Re: International Toll Free Numbers (Thierry Samama)
Obtaining Files From International Telecommunications Union (Carl Law)
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Date: Thu, 24 Mar 94 08:57:28 -0500
From:
[email protected] (A. Padgett Peterson)
Subject: Frequently Asked Questions About Caller-ID
[TELECOM Digest Editor's Note: This file will become a permanent
entry in the Telecom Archives. PAT]
Frequently Asked Questions About Caller-ID
v1.0 Mar. 1994
1) What is Caller-ID ?
First ask "What is ANI"
2) OK, What is ANI ?
ANI or Automatic Number Identification is a mechanism by which
the different telephone companies determine what account is to be
charged for a call, This information is passed between Telcos and
was originally for billing purposes.
Since the Telcos had it anyway, the decision was made to make it
available to authorized parties such as 911 service and law
enforcement agencies. ANI is also used to let a Telco operator
know who is calling.
More recently, ANI is used to report to 800 and 900 subscribers,
who made the calls they have received, in the first case so that
the 800 subscriber knows who the charge is for, and so that 900
number subscribers know who to charge.
3) Now (maybe) what is Caller-ID ?
Caller-ID (more properly CNID or Calling Number IDentification)is
a Telco service that is a byproduct of (but not exactly the same
as) ANI. In this case, only those numbers reported by subscribing
exchanges are returned, exactly which are and which are not is at
the Telco's discretion (in theory, since the Telco has all of the
numbers via ANI, *something* useful could be reported for any
call. Most Telcos do not).
The Federal Government has stated that it is their intent that
nationwide CNID be available by mid-1995.
Currently there are two types of Caller-ID. The first (often
referred to as "basic" service) just returns the calling number
or an error message and the date/time of the call.
The second ("enhanced" Caller-ID) also returns the directory
information about the calling number.
4) How is the Caller-ID information provided ?
As a 1200 baud, 7 data bits, 1 stop bit data stream usually
transmitted following the first and before the second ring signal
on the line.
The signal is provided before the circuit is complete: picking up
the receiver before the data stream is finished will stop/corrupt
the transmission.
Currently there are two types of information returned: a "short
form" which contains the date/time (telco and not local) of the
call and the calling number or error message. The "long form" can
also contain the name and/or address (directory information) of
the calling phone.
The "short form" stream consists of a set of null values,
followed by a two byte prefix, followed by the DATE (Month/Day),
TIME (24 hour format), and number including area code in ASCII,
followed by a 2s compliment checksum. Most modems/caller id
devices will format the data but the raw stream looks like this :
0412303232383134333434303735353537373737xx
or (prefix)02281334407555777(checksum)
A formatted output would look like this:
Date - Feb 28
Time - 1:34 pm
Number - (407)555-7777
5) Can a Caller-ID signal be forged/altered ?
Since the signal is provided by the local Telco switch and the
calling party's line is not connected until after the phone is
answered, generally the signal cannot be altered from the distant
end. Manipulation would have to take place either at the switch
or on the called party's line. (never say "never")
6) What is "ID Blocking" ?
Most Telco's providing Caller-ID have been required to also
provide the ability for a calling party to suppress the Caller-ID
signal. Generally this is done by pressing star-six-seven before
making the call. In most cases this will block the next call only
however some Telcos have decided to implement this in a
bewildering array of methods. The best answer is to contact the
service provider and get an answer in writing.
Currently this is supplied as either by-call or by-line blocking.
By-Call is preferred since the caller must consciously block the
transmission on each call. By-Line blocking as currently
implemented has the disadvantage that the caller, without having
a second caller-id equipped line to use for checking, has no way
of knowing if the last star-six-seven toggled blocking on or off.
7) What happens if a call is forwarded ?
Generally, the number reported is that of the last phone to
forward the call. Again there are some Telco differences so use
the same precaution as in (6). If the forwarding is done by
customer owned equipment there is no way of telling but will
probably be the last calling number.
8) What happens if I have two phone lines and a black box to do
the forwarding ?
If you have two phone lines or use a PBX with outdialing
features, the reported number will be that of the last line to
dial. Currently there is no way to tell a black box from a human
holding two handsets together.
9) I called somebody from a company phone (555-1234) but the
Caller-ID reported 555-1000.
Often a company with multiple trunks from the Telco and their own
switch will report a generic number for all of the trunks.
10) I run a BBS. How can I use Caller-ID to authenticate/log
callers ?
There are two ways. The first utilizes a separate Caller-ID box
with a serial cable or an internal card. This sends the
information back to a PC which can then decide whether to answer
the phone and what device should respond. Some of these are
available which can handle multiple phone lines per card and
multiple cards per PC.
The second (and most common) is for the capability to be built in
a modem or FAX/modem. While limited to a single line per modem,
the information can be transmitted through the normal COM port to
a program that again can decide whether or not to answer the
phone and how. There is a FreeWare Caller-ID ASP script for
Procomm Plus v2.x available for FTP from the Telecom archive.
Most such software packages will also log each call as it is
received and the action taken.
Of course for true wizards, there are chips available (one of the
first was the Motorolla MC14544TP) that can recognize the CNID
signal and tranform it into a proper RS-232 (serial) signal.
11) How is security enhanced by using Caller-ID over a Call-Back
service or one-time-passwords for dial-up access ?
Caller-ID has one great advantage over any other mechanism for
telephone lines. It allows the customer to decide *before*
picking up the receiver, whether to answer the call.
Consider hackers, crackers, and phreaks. Their goal in life is to
forcibly penetrate electronic systems without permission (sounds
like rape doesn't it ?). They employ demon dialers and "finger
hacking" to discover responsive numbers, often checking every
number in a 10,000 number exchange.
If they get a response such as a modem tone, they have a target
and will often spend days or weeks trying every possible
combination of codes to get in. With Caller-ID answer selection,
the miscreant will never get to the modem tone in the first
place, yet for an authorized number, the tone will appear on the
second ring. Previously the best solution for dial-ups was to set
the modem to answer on the sixth ring (ats0=6). Few hackers will
wait that long but it can also irritate customers.
12) What error messages will Caller-ID return ?
a) Out of Area - (Telco) the call came from outside the Telco's
service area and the Telco has chosen not to return the ANI
information.
b) Blocked or Private - (Telco) the caller either has permanent
call blocking enabled or has dialed star-six-seven for this call.
You do not have to answer either.
c) Buffer Full - (device manufacturer) there are many Caller-ID
devices on the market and exactly how they have chosen to
implement storage is up to the manufacturer. This probably mans
that the divide has a limited buffer space and the device is
either losing the earliest call records or has stopped recording
new calls.
13) Why are so many people against Caller-ID ?
FUD - Fear, Uncertainty, & Doubt or 10,000,000 lemmings can't be
wrong. There were some justifiable concerns that some people
(battered wives, undercover policemen) might be endangered or
subject to harassment (doctors, lawyers, celebrities) by
Caller-ID. As mentioned above there are several legitimate ways
to either block Caller-ID or to have it return a different
number. It is up to the caller. The advantage is that with
Caller-ID, for the first time, the called party has the same
"right of refusal".
Expect yet another Telco service (at a slight additional charge)
to be offered to return an office number for calls made from
home. Crisis centers could return the number of the local police
station.
Compiled by Padgett Peterson. Constructive comments to:
[email protected] Brickbats >nul.
------------------------------
From:
[email protected]
Subject: CATV Modems
Organization: University of Geneva, Switzerland
Date: Thu, 24 Mar 1994 08:12:15 GMT
A CATV cable has a huge bandwidth available. A part of it is usually
not used for TV channels and could be used (at least from a technical
standpoint) for data transmission, if a return channel is available.
Do you know any equipment (modem, remodulator, ...) that allows data
communication over the CATV cable. On the user side, the modem should
feature a well-known interface (RS232C, Ethernet, ...).
Dominique Gabioud
[email protected]
------------------------------
Date: Thu, 24 Mar 1994 07:21:10 EST
From: Peter M. Weiss <
[email protected]>
Subject: FCC Gopher Service
Organization: Penn State University
I don't recall seeing this posted here (
[email protected]) --
Date: Wed, 23 Mar 1994 17:12:09 -0600
From: Bob Keller <
[email protected]>
To: Multiple recipients of list <
[email protected]>
Subject: Finger FCC Releases
Taking a page from John Higgins' book, I will be temporarily putting
five days' worth of FCC Daily Digests pulled from ftp.fcc.gov in my
.plan file so that it can be accessed by fingering <
[email protected]>.
This is being done for experimental purposes, but if anyone finds it
useful in the meantime, so much the better. Be sure to open your
capture buffer first, as the file is many screens long.
It is also possible to Gopher to the FCC site [Gopher fcc.gov] as well
a regular old ftp. Reportedly, the FCC is planning eventually to have
an e-mail server and/or mailing list for accessing documents.
Bob Keller Robert J. Keller, P.C. Internet:
[email protected]
---------- Federal Telecommunications Law Telephone: +1 301.229.5208
KY3R 4200 Wisconsin Ave NW #106-261 Facsimile: +1 301.229.6875
Washington, DC 20016-2143 USA CompuServe UID: 76100.3333
------------------------------
Date: Wed, 23 Mar 94 16:44:47 EST
From: Carl Moore <
[email protected]>
Subject: Re: Country Code For San Marino
+39 549 does appear in the Telecom Archives as "supplied by British
Telecom" or words similar.
------------------------------
From:
[email protected]
Subject: Re: Country code for San Marino
Date: Thu, 24 Mar 94 13:18:41 MET
Bill Hofmann writes:
> Well, I checked with Sprint, they told me 378, however, I received a
> private communication from someone in Rome who told me that as of
> 1990, San Marino had been split from 541 and now has Italian city code
> 549, and that further both country codes 295 and 378 are disallowed
> from Rome. Can some folks in other countries check this out?
The Dutch telephone authorities mention +39 549 for access to San Marino.
Bob Smeets
------------------------------
Subject: Information Wanted on Women and Telecom
Date: Wed, 23 Mar 94 15:18:52 EST
From: Melanie Spencer <
[email protected]>
I'm looking for information on women in telecommunications -- particu-
larily statistics on participation and any cases of discrimination.
[TELECOM Digest Editor's Note: In the past, women generally were in the
front office -- line of fire -- positions directly interacting with the
subscribers as service representatives and operators while men were
in management and research. That is still true today, although not to
as great an extent as a half century ago. Which jobs are 'more important'?
I guess since the subscribers are the ones paying the bill, their inter-
action with the 'phone company' through the operators and service reps
is the most important consideration in how telco functions in my opinion,
yet their wages and the way they are treated does not always reflect
that, sorry to say. PAT]
------------------------------
From:
[email protected]
Subject: Request For Info: Strategic Planning For Local Exchange Carrier
Date: 23 Mar 1994 22:54:50 GMT
Organization: INFOnet - Iowa Network Services, Inc.
Reply-To:
[email protected]
I am asking for any resource info anyone might have regarding
strategic planning models for local exchange carriers (telephone
companies), specifically rural telephone companies.. I am working on a
thesis for a master's in telecommunications and my topic is to prepare
a strategic planning model for rural Iowa independent telephonies in a
competitive environment.
If there is info on strategic planning in a metro environment for telcos,
that would be welcome as well. I would appreciate anything -- books,
thesis materials, journals, etc. for my literature search and to ensure
that nothing has been done on this same topic previously.
Please leave any info in my email. Thanking you in advance.
Jan Lovell, Assistant Manager,
Clear Lake Independent Telephone Company,
Clear Lake, Iowa
------------------------------
Date: Wed, 23 Mar 1994 15:38:10 -0800
From:
[email protected] (David McCord)
Subject: Re: Please Explain the Term 'Steaming Terminal'
Steve <
[email protected]> wrote:
> Could someone explain what this term means. Please email.
I guess these is a corrupted reference to "streaming terminal."
On a multipoint data communications line, if two or more devices
attempt communications simultaneously, transmission fails. To avoid
this, a typical protocol arrangement provides for devices to transmit
ONLY when specifically requested to do so.
A streaming terminal is one that is in violation of this arrangement,
usually in a manner so that it is constantly transmitting and thereby
fouling operation of the entire line. This can be a serious problem.
[email protected] International Network Services
+ 1 415 254 4229 voice Mountain View, California, USA
+ 1 415 967 3247 fax
------------------------------
From:
[email protected] (Terry Gilson)
Subject: Re: Who Paid For My 550?
Date: 24 Mar 1994 08:18:54 GMT
Organization: Delphi Internet Services Corporation
On Wed, Mar 23, Jim Cluett <
[email protected] asked:
> Can anyone explain the economics of the $50 Motorola 550? The 550 is
> selling locally at a discount department store for $50. Motorola can't
> build 'em for that. The department store is acting as an agent for
> both an A and a B carrier, but I don't think they can recover enough
> from a year's contract to make up the difference. Who's subsidizing
> this? It's probably me, but I don't quite see how.
I'm not sure what it costs Motorola to make the 550, however, the
current wholesale price to the Cellular Industry is from $250 to $280
depending on where you get it, and deals with certain carriers bring
it down lower than that. The department store you bought the phone
from probably does not make anything from the on-going use of the
phone, instead they may get a one-time commission for the activation
of a number. This commission can run from $75.00 to $300.00+ depending
on the rate plan and part of the country.
It is the commission from the carrier that usually brings the phone
prices way down. Gillette's theory ... give away the razor but charge
a lot for the blades.
In states where the cellular industry is regulated, such as California,
the dealers can only sell up to $25.00 below their cost, and a quick
glance through the newspaper advertisements will give you a pretty
good idea of the cost of each phone.
In my area, which is Southern California, our average phone bill is
now around $135.00 per month including access charge and airtime. Most
Carriers can recoup the commission paid for a number within the first
year and still make some decent, or indecent ;-), profit.
Terry Gilson
[email protected]
DCN Cellular 805-379-3333
[email protected]
Westlake Village, CA
[email protected]
------------------------------
Date: Thu, 24 Mar 94 06:02:14 EST
From:
[email protected] (Dave Niebuhr)
Subject: Re: Area Code 562
In a recent TELECOM Digest Issue
[email protected] (Rich Greenberg)
wrote:
> Pacific Bell & GTE just anounced that in 1996, LA will get its fourth
> area code. 562 will overlay the present 213-818-310 areas, and will
> be used for cellular phones and pagers.
> Four area codes in one metro area. Can anybody beat that?
and thus did the Editor write:
> [TELECOM Digest Editor's Note: Well the New York City metro area has quite
> a few now: 212/718/914/907, what else? Are we counting New Jersey? PAT]
^^^ ^^^
907 is Alaska; it is 917
914 is metro NYC covering Rockland, Westchester, part of Orange and
possibly Dutchess and Putnam counties.
Add AC 516 (Long Island) and parts of ACs 201/708 (NJ) and part of
AC 203 (Ct.)
With the exception of NJ, all of the ACs listed are part of the NYC
LATA.
Dave Niebuhr Internet:
[email protected] (preferred)
[email protected] / Bitnet: niebuhr@bnl
Senior Technical Specialist, Scientific Computing Facility
Brookhaven National Laboratory Upton, NY 11973 (516)-282-3093
------------------------------
Date: Thu, 24 Mar 1994 07:09:22 -0500
From: Jonathan_Welch <
[email protected]>
Subject: Re: Telecom Business Idea
In article <
[email protected]>,
[email protected] (Dale Van
Voorst) writes:
> I am looking for input on a telecommunications business idea that I
> have. I live in a relatively small town that does not have local
> access numbers for any of the on-line services (Compuserve, Prodigy,
> AOL, etc). If you want to access these services, you must pay long
> distance charges on top of your normal membership fees.
If you're going to go to the trouble of leasing a line you might be
better off setting up a 486DX50 pc running linux and lease the line to
an internet provider. You'd then sell accounts on your machine for a
flat monthly rate. You'd have to be sure your local calling area
encompases enough subscribers so you don't end up losing money.
Jonathan Welch VAX Systems Manager Umass/Amherst
[email protected]
------------------------------
Date: Thu, 24 Mar 94 14:11:54 +0100
From:
[email protected] (Thierry Samama)
Subject: Re: International Toll Free Numbers
Reply-To:
[email protected]
Organization: Alcatel Alsthom Recherche (France)
In article
[email protected],
[email protected] (Rachid Benzaoui)
writes:
> How would it be possible to know the French equivalent numbers of American
> international toll-free numbers?
In France, international toll free numbers are of the form 05 90 mc
du, where 05 is the usual toll free prefix. Also, I believe (but that
would need to be confirmed) that toll free choke numbers are 05 70.
------------------------------
Subject: Obtaining Files From International Telecommunications Union
Date: Thu, 24 Mar 94 09:06:11 CST
From: Carl Law <
[email protected]>
Reply-To:
[email protected]
I am a new user on Usenet. I write telecom articles for various
journals and for the {Financial Times} in London, but live in Northern
Ireland where, so far, I cannot track down the ITU yearbook and
analogous publications. Could you possibly tell me the command
sequence on Usenet to punch thru to their computer in Geneva?
Regards,
Carl Edgar Law in Belfast, N. Ireland.
[TELECOM Digest Editor's Note: Well, first of all, we do not want to
confuse 'Usenet' (a collection of newsgroups circulated via 'Internet',
a network which joins together computers and other networks around the
world with the Internet itself. The Internet is much, much larger than
just the component we call Usenet, which coincidentally is just one of
a few different collections of newsgroups. There is also a collection
of newsgroups in a system called 'alt' -- they're not technically part
of Usenet -- and there are numerous regional and local collections of
newsgroups with limited circulation. What you want to know, I think,
is how to connect to the computer at ITU using the facilities of your
local site in conjunction with the Internet. Usenet has nothing to do
with it.
The network address of the International Telecommunications Union is
'itu.ch'. The 'ch' stands for Switzerland, and the ITU is located in
Geneva. For starters, you need to be using a computer (or connected
through your personal PC or terminal to a computer) which is connected
to the Internet in one way or another. If a realtime, live connection
exists, then you can connect to ITU using 'anonymous ftp', and perhaps
using other similar services such as Gopher or WEB. The instructions
for those services are detailed, and I won't cover them here right
now. Without having a realtime online Internet connection, then the
thing you would have to do is send email provided ITU has an automated
program running to process email *as though it were coming via ftp*.
At this point I will defer to our friends at ITU since we have not
heard from them in awhile anyway, and perhaps Lucio or someone else
there will forward a file dealing with the ITU public documents and
how to obtain them. I am making this deferral since I believe in the
next few days there will be an important announcement to share with
all readers of TELECOM Digest (jointly by the ITU and myself) and it
would be good to do it all at the same time. In the meantime, Carl,
what you should do is make inquiries of your system administrator
regards remote connectivity to other computers using ftp, Gopher and
similar services. The way it is done is universal, meaning not only
are the instructions pertinent to connecting with ITU, but to any site
where there may be documents you wish to obtain. PAT]
------------------------------
End of TELECOM Digest V14 #145
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