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Private Line 1
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PRIVATE LINE: A JOURNAL OF INQUIRY INTO THE
TELEPHONE SYSTEM
JUNE 1994: VOLUME 1, NUMBER 1
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TABLE OF CONTENTS
1. General Information on private line
2. The Front Cover and The Inside Front Cover
3. The Editorial Page
4. Telco Payphone Basics, Part 1
5. The Post Pay Coin Line
6. A Conversation With Motorola
7. The GTE RTSS Phone
8. California Toll Fraud Law
9. Ad rates and Miscellaneous Information
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1. General Info on private line: ISSN No. 1077-3487
A. private line is published six times a year by Tom Farley. Copyright
(c) 1994 FACTSHEET5 calls it "A great companion to 2600."
B. Subscriptions: $24 a year for subscriber's in the U.S. $31 to Mexico
and Canada. $44 overseas. Mailed first class or air rate .
(1) Make checks or money orders payable to private line
(2) A sample is four dollars. Back issues are five dollars apiece.
The magazine is black and white. Double columns. Largely footnoted.
(3) The mailing list is not available to anyone but me.
C. Mailing address: 5150 Fair Oaks Blvd. #101-348, Carmichael, CA
95608
D. e-mail address: privateline@delphi.com
E. Phone numbers: (916) 488-4231 (Voice) (916) 978-0810 (FAX)
F. You may put this file up at any internet site or bulletin board that you
wish. All I ask is that you reproduce the file it in its entirety and that
you not sell a hardcopy version of the output.
G. Comments and corrections are always welcome. I welcome
submissions and I pay with subscriptions. You don't have to write in
my style.
NB: I am now accepting electronic related advertisements for the
January, 1995 issue. This will be the first newsstand edition of private
line. Distributed by Fine Print Distributors, Austin Texas. Ads are $75
for a full page, $37.50 for a half page and $18.75 for a quarter page.
No subscription required. Subscribers get free classifieds of 25 words
or less.
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2. THE FRONT COVER AND THE INSIDE COVER
The front cover artwork of this issue is from a 1965 Western Electric
advertisement. It is an edge on photograph of five circuit boards that
were used in the Number 1 ESS. I included the text of that ad in the
inside cover page. It reads:
"Electronic components by the thousands arrayed on circuit boards.
These are at the heart of the Bell System's highly complex new
Electronic Switching System. Now being built at Western Electric, a
typical electronic system uses 160,000 diodes, 55,000 transistors,
226,000 resistors, capacitors and similar components. Over the next
few years, millions of American telephone users will benefit from the
new services ESS will offer. But for Western Electric the coming of
ESS presents a technical challenge equal to any we have faced in the 83
years we have been a member of the Bell System. Not only do we stand
behind the quality of the thousands of components, but we also make
sure that each of these precision parts is assembled exactly. For the end
requirement is that they work perfectly, each with each, and with every
other of the billions of components in the nationwide Bell System
communications network. We are able to do this job because, as
members of the Bell System, we share its goals. Working together with
people at Bell Telephone Laboratories, where ESS was developed,
Western Electric people strive for perfection that enables your Bell
telephone company to bring you the finest communications service in
the world."
-- Western Electric, Manufacturing & Supply Unit of the Bell System
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3. THE EDITORIAL PAGE
private line
a journal of inquiry into the telephone system
Setting the Agenda; A Rambling Mission Statement From Your Editor
The magazine 2600, The Hacker Quarterly, rekindled an interest in
telephones that had laid dormant with me for over fifteen years. private
line is an outlet for my interest in one the most marvelous, mysterious
and elaborate inventions that man has ever invented: the telephone
system. I hope that you find it a creative outlet for yourself as well. Let
me tell you what I think are important goals for this magazine.
1. This magazine will write for the beginner. There is a lack of good,
clear information for the beginner in telephony. Most texts and articles
assume a working knowledge of the fundamentals. That won't be the
case here. Books and magazines about telephony often read as though
one electrical engineer was writing to another. That's because they
usually are. But who writes for the beginner? This magazine will.
2. This magazine will turn articles into brochures. I want the
information developed here to do more than sit in back issues. This
material will go toward a series of beginner brochures on telephony.
The magazine itself will be consecutively paged and indexed yearly.
References will be given whenever possible.
3. This magazine will encourage questions about the information
presented. I want to be corrected if I make a mistake. I want people to
feel free to contribute and to question and to challenge anything that
appears here. The articles that I write are not the Last Word, rather, they
are my best attempt to explain some difficult subjects. They are a
starting point for a discussion of the topics involved. I have an ego as
far as presentation and layout go. But I have no ego as far as being
corrected.
I hope you contribute. I welcome the comments of hackers, futurists,
telecom people and technology buffs. Anyone who is interested in the
telephone system is welcome to participate. I am really a beginner to
telephony myself; let's learn together.
Tom Farley
privateline@delphi.com
p.s. my handle is 'Sherman' and my callsign is KD6NSP
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4. Telco Payphone Basics, Part 1
A. Telephone Company Payphone Basics, Part 1
1. A telco payphone is one that is owned and operated by the phone
company that provides local telephone service: a former Bell company,
GTE, General Telephone or another independent. Ownership aside,
however, the one thing that makes a telco payphone a telco payphone is
the fact that the machine's decision making ability resides in the phone
system and not in the machine itself. This is different than a COCOT
(customer owned, coin operated telephone) which makes most decisions
on its own. When people can choose their local carrier, the so called
alternate dial tone, ownership will be a less important criteria. You
might have MCI as your telco, for example, instead of Pacific Bell.
Let's start at the beginning.
B. The Different Coin Lines
2. There are two classes of coin phone service and three kinds of coin
lines. The first class is post-pay, in which coins are deposited after a
connection is made. Post-pay provides a dial tone without a deposit.
The second class is pre pay in which a deposit is needed before a
connection is set up. The three kinds of coin lines are called post-pay,
for its operating method; coin first, which means that a deposit is needed
to get a dial tone; and dial tone first, the pre-pay service that provides a
dial tone without a deposit. Coin first is probably a defunct operating
system. Dial tone first is by far the most common
kind of coin line.
C. What Is a Line?
3. A line can be two things in telephony: a wire that carries a phone call
or a channel in a wire or cable that carries a call. In either case, a line
connects a coin phone or a customer phone to the switching office that
provides local service. It is distinguished from a trunk which connects
switching offices to each other or switching equipment within an office
to each other. A line is almost always used in conjunction with local
service, whereas trunks are thought of as providing long distance or toll
service.
4. In addition, a line can pass different voltages to signal different
things. A trunk cannot. For example, a line can carry +48V DC to
signal keypad inhibit, +130VDC to signal coin collect, and 75VAC to
ring the phone. A trunk's voltage, however, remains the same. It must
since the cable containing the trunk is usually carrying many calls at
once; it is impossible to selectively control voltage within a channel in a
common wire. Thus, lines and trunks often use different kinds of
signals.
5. A coin line is the circuit that connects a payphone to a central office or
an end office. The line uses two copper wires, collectively called the
twisted pair. There is nothing special about the wires themselves. There
is no set
of common wires that runs to all the payphones served by a central
office. The phrase coin line is a designation. It indicates that the line
needs special equipment at the central office to work. And since the
equipment at the CO can vary, so can the kind of coin line.
6. In addition, most telco coin lines are somewhat permanently
connected to their switch. That is, the coin phone line is known to the
central office to be a coin line. You would not, for example, have an
unrestricted dial tone if you connected your lineman's handset to the
wires. Instead, you would still be prompted for an initial deposit and
you would still be asked by ACTS (1) to pay for long distance. At the
very least, polarity would be reversed and long distance calling would
be intercepted by an operator.
7. Post-pay, coin first and dial tone first refer to the kind of coin line
service that exists at a particular central office. The switching equipment
and its accessories determine the kind of coin line service. Let's look at
the two classes of lines more closely.
D. The Metallic Line
8. A line was originally defined as a "(w)ire or wires connecting stations
in a telephone or telegraph system."(2) It often used as shorthand for
transmission line. It is also called a VF or voice frequency line. And
sometimes it's called an analog line. Two wires called a twisted pair or
paired cable connect most phones to an end office or a connecting point
to the end office. This is 19 to 26 gauge insulated wire. Look inside a
service terminal to see twisted pair. The terminal is the point where your
house or office phone line and the telco wiring connects, usually on an
outside wall.(3) The phrase trunk line is often heard. That's not a
combination of trunk and line, but, again, a reference to the trunk as a
transmission line.
9. A metallic line exists if there is a direct, physical connection with the
end office and each subscriber's phone. Step by step offices, for
example, may have each customer's twisted pair directly wired to a
particular place in the switching frame. This metallic connection also
exists with open wire, which uses copper wires strung from utility
poles. In this case, twisted pair runs from the house or business to an
aerial service terminal. Two uninsulated wires then go toward the end
office, or more probably, a connecting point to the office. A metallic
line, therefore, may change from one kind of wire to another. But it
always keeps a copper connection of some sort for each subscriber
phone or payphone.
10. Both twisted pair or open wire help complete an electrical
connection or circuit between the phone and the office. Circuit is often
used interchangeably with line, creating more confusion than it should.
Since this pair forms a circuit in the shape of a loop, it is often called the
loop. The wires are also occasionally called conductors. That's because
they conduct the electricity that operates the phone as well as carrying
the conversation itself. The wires themselves are called tip and ring.
Some assume that one wire is negatively charged and the other
positively charged. Not so. Tip and ring do not refer to a pre-designated
electrical state. As mentioned before, both tip and ring will have
negative or positive voltages placed on them to signal different things.
11. Not all lines, however, are based on a physical, metallic contact
with their local switch. This is especially true with long distances
between a phone and its end office. Resistance builds in a line as length
increases. Signal strength goes down at the same time. Many means
have been used to extend the length of the coin line or the subscriber line
beyond, say, six miles.(4) At some point though, the conventional
metallic line becomes unfeasible. Amplifiers or repeaters are needed to
take the signal further. And a different operating system is needed to go
along with this equipment. In these cases, the metallic pair may
terminate at a connecting point to the central office. Special equipment
then puts many, many subscriber lines on a single cable or a group of
wires. The CO then provides a channel within the transmission line only
when it detects that a phone has gone off hook. There is no longer a
physical connection between each customer's twisted pair and the
central office equipment. Let's look at the non-metallic line.
E. The Non-Metallic Line
12. The second definition of a line is that it is the communication
channel connecting the subscriber to the local office. A line in this case
represents an individual radio frequency that a phone call is placed on.
These are called carrier frequencies. This differs from the voice
frequency that carries the call in a normal line. This kind of line is also
called carrier. Many, many conversations can be placed on a single
wire through a process called multiplexing. (5)The most familiar
example of multiplexing might be a cable TV line. A single wire or
coaxial cable can carry dozens of television channels. The simplest form
of multiplexing in telephony is called split carrier.
Split carrier
13. Split carrier uses a single twisted pair to carry more than one phone
call. It is also called subscriber carrier. Some include this in a larger
category called pair gain systems. It is not usually used to overcome
long distances but rather to provide another line when there is no free
twisted pair. In older buildings, for example, spare lines are frequently
not available. In fact, you may be using split carrier now and not know
it. "Whining sounds, echoes and slow dial tone response"(6) may
indicate that your telephone line is being split and that your line is on the
carrier side. Another sign might be if your modem does not work on
your telephone line but does on your neighbor's. That's because the
modem is using a carrier of its own to transmit information. The two are
rarely compatible. A line on the carrier side is only a voice grade line.
14. The voice frequency or VF channel is the normal, background
path that carries a conversation on a twisted pair. You'll also hear the
terms base band, voice channel and voice path. This is the first channel
of two on split carrier. The second channel is created by transmitting a
radio frequency at, say, a constant 100 kilohertz. That's a hundred
thousand cycles per second. By comparison, the AM radio band begins
at about 540 kilohertz. The signal of the second line is impressed on the
steady carrier frequency. This causes the carrier signal to move up and
down or modulate according to the changes in speech. So, two
channels are now on one line. One conversation doesn't affect the other
because you can't hear radio frequencies unaided. You now have a
carrier line and not a voice frequency line. Subscriber carrier needs
special equipment. I doubt that any coin phone uses this technique
because of the number of voltage driven signals that must pass down the
line. Never-the-less, some telcos may use split carrier for a public
phone instead of a party line in rural areas. Perhaps. Let's look at more
complicated multiplexing schemes. Again, these are examples of non-
metallic lines.
Analog multiplexing
15. Both split carrier and voice frequency lines use analog signals.
That's because normal speech, music and tones are all analog signals,
once they're on the phone line. They are analogs, electrical
representations of speech.(7) They are not altered or converted to a
digital form. In other words, routine traffic in the local loop. Analog
multiplex systems are used primarily for trunk traffic, that is, handling
calls between switching offices. Analog carrier or N carrier is rarely
used in the local loop. So, I'll discuss it more in the section on trunks.
Some multi-channel analog systems do tie a customer's phone to its
local switch but I have not found much information on them.
Specialized equipment would be needed for coin phones; installed at the
point where the multiplexer connects to the twisted pairs. This is needed
to translate payphone signals from the central office to the voltages that
control the phone. As I mentioned before, a channel in a cable cannot
handle different kinds of direct current signaling. But twisted pair can.
Hence, a need for an interface.
16. It seems that most telcos decided that if they were going to install a
carrier system for the local loop, they were going to use digital
techniques. Both digital and analog multiplex systems use amplifiers or
repeaters to keep signal strength up over long distances. Even so,
analog signals degrade with distance. But digital signals remain stable
for the length of their trip. That's because they are not an electrical
representation of speech but a mathematical or numerical
representation.
Digital multiplexing
17. You've probably seen a sine wave of an analog signal. It's a rise
and fall pattern. By plotting its coordinates on graph paper, you know,
C-3, B-4, A-2 and so on, we can record its shape in a numerical or
digital form. And the more points we plot the more accurate the record
becomes. Digitizing produces its plots by instantaneously measuring
the ups and downs of signal strength. In T1, a signal's strength is
measured or sampled two things: 1), the strength level itself and 2), the
time at which it occurs. These two measurements or electrical plots are
converted to binary numbers or bits. An eight bit group makes up a
byte. Blocks and blocks of these fast moving digits then represent
speech.
18. Sampling takes a lot of measurements. But it is not continuous,
even at eight thousand times a second. There are always small gaps.
These breaks and blocks differ an analog signal from a digital one. A
digital signal is made up of discrete units whereas an analog signal is a
continuous unit. Built in error checking and uniform rules for encoding
and decoding enables digitizing to faithfully reproduce a signal over
thousands of miles. Fike gives some good examples in "Understanding
Telephone Electronics." A digital carrier system makes the most sense
when it ties into a digital central office. This saves the step of converting
digital signals back to the analog ones that a simple end office can deal
with.
19. T1 or T carrier is the most common form of digital transmission
used in the local loop. T1 is used primarily for trunks but it also
provides tens of thousands of local lines to central offices and remote
switches. This system converts the normal analog signal of a subscriber
pair into a digital signal The signal is abbreviated as DS. A typical digital
multiplex system might be Western Electric's SLC-96. (Subscriber loop
carrier, version 96) It can accept 96 local subscriber lines. But only five
wires may run to the distant office since the signals are multiplexed.
We'll look at how it interfaces with the twisted pairs of the local loop in
the discussion of the local switch.
F. The Local Switch
20. The kind of coin line service provided usually depends on the
equipment installed at the local switch. The type of switch itself is often
less of a concern than the options that go with it. Post-pay operation, for
example, usually depends on an end office with step by step switching
equipment. But step by step can be converted to pre-pay. On the other
hand, most crossbar switches and all electronic switches have been
configured for pre-pay service already.
21. Most central offices controlling payphones need the hardware that
enables automated coin toll service (ACTS).This is a system wide
program that handles most long distance calls from payphones. It's
what you get when you dial a 1+ call from most of the country. The Bell
System designed this program in the late 1970's for use by all the
regional Bell companies as well as subscribing independents.(9) Calling
card service was developed a few years later.(10) This required
additional equipment. Not having this equipment means that a particular
CO may not provide coin line service. This is why you'll often see
payphones in a town grouped to a certain prefix. It's a sign that that
exchange has had certain hardware installed. In addition, the kind of
trunk lines and local lines that the CO connects to will also influence the
way that an office is configured.
22. I'm not sure if it's profitable for me to spend much time discussing
individual switches. Many, many books have been written on them and
their variants.(11) Comparatively little has been spent on discussing step
by step offices or switches below
the central office. So, I'll do that. The discussion of the individual coin
line may give more information an a particular switch. The post-pay
section, for example, deals with the community dial office in detail.
We'll look at it in general here and then mention other end offices.
G. The End Office
23. The end office is your local switch, the one that your subscriber line
or coin line is first tied to. It is at the bottom of the switching hierarchy,
a so called class five office. This is usually a central office but not
always. Many, many rural communities are served instead by a
community dial office or CDO. These are mostly step by switches,
serving far fewer lines than a normal central office handles. Slightly
closer communities may be served by a digital switch called a remote.
The CDO depends on a central office that can be quite a distance away.
They are usually connected by an analog carrier or T1 to the central
office. Most CDO's don't have trunks to the outside world. Long
distance service needs to go out through the central office. A CDO may
not generate its own dial tone. But it does generate the power necessary
for the local phones to work. Some CDO's are called package offices.
24. Package offices seem to refer to a particular switching arrangement,
particularly the No.5 Crossbar package community dial office.(12) This
was a system of trunks and hardware that retrofitted certain CDO's. The
dial office had to use the Number 5 crossbar as its central office switch.
This package brought many features of the number 5 to rural areas.
This was an expensive arrangement. These offices had to have enough
traffic and revenue to justify it. I expect that they have probably been
replaced in former Bell System country, since greater revenue drives
quicker upgrading. I would welcome hearing about any crossbars that
are still in operation. So, what kind of CDO took its place?
H. The remote switching system
25. The RSS No. 10 or Remote Switching System was the Bell
System's answer to improve rural service in about 10% of their outstate
CDO's.(13) A subscriber' s line connected to the RSS. The RSS uses
T1 to connect with an electronic office or ESS as far as 175 miles away.
They were originally configured to work with the No.1ESS and then the
1AESS. Most but not all of these older CO's have been retired. An
electronic switch, the RSS No.10 shares much of the same architecture
as its bigger brothers. Even, so, the CO controlling the switch has to
have certain hardware installed in order to work with it.
26. Wire pairs from the local loop would terminate inside a small
building containing a remote switch and the T1 carrier facility. The RSS
provides power to the loop and the T1 equipment sends the subscriber
traffic to the ESS office. A payphone would be enabled by a special
circuit board inside the T1 service cabinet. This plug in module
provides the proper interface to the switch.(14) The RSS would provide
the power necessary to implement all the voltages needed for signaling
the coin phone. One interesting aspect is that a TSPS operator could
handle a coin call from as much as thousand miles away, since it is the
distance from the CO to the operator that is now a controlling factor, and
not the distance from the payphone to the central office. Another remote
switch seems to be the DMS-10.
27. The DMS-10 switching system is a Northern Telecom product
designed to Bell System standards. It handles 200 to 6000 lines. Why
did Bell use an NT product? Cost. The DMS-10 is a small digital
switch. It can provide some custom calling services that may generate a
little more revenue than a normal rural switch. This may help the telco
generate a faster return on its money in a low traffic area. The ultimate
remote switch is probably the No. 5A Remote Switching Module.
28. The No. 5A Remote Switching Module or RSM, is, as you've
guessed, the specific remote switch for the No.5ESS. T-1 or fiber optic
takes the local traffic to the No. 5. The big difference here is that this
switch can pass long distance calls to the network without going
through the central office first. A CDO doesn't normally have trunks to
the outside world. With this CDO, however, the trunks are so arranged
that long distance traffic may go directly to a toll office and not first to
the CO. The term CDO is applied less and less as the years go on.
People often just call these switches remotes or modules.
29. It's impossible in an introduction to cover all the possible
configurations of the end office. There are many, many kinds of
arrangements. The most important thing to remember is the dependence
of the CDO or remote switch on the central office. Microwave radio
may be used in some areas to connect to a central office. A cellular
phone site is also an end office. It provides dial tone. I know that
Ericksson digital switches have been installed in many Motorola built
cell sites.
I. A few thoughts on step by step
30. Step by step switching is still with us. And probably for a little
longer. In fact, step by step may outlast crossbar, a different kind of
switching system deemed superior to step by step, or SXS as it's
sometimes abbreviated. Apparently, the Bell System choice for SXS
was Western Electric's No.355A. In 1974, step by step was used by the
Bell System for 22 million phone lines, one half million of which were
coin lines.(15) By 1980, 15 million lines were still in service. Step by
step was to be phased out by 1990.(16) That would have eliminated the
800 central offices with SXS in ten years. Does anyone have an updated
census of the regional holding companies, the former baby bells? The
story outside of the former Bell System is very different.
31. Telephony magazine used to publish a directory and buyers' guide
that was invaluable. It was a roster of the non-Bell operating
companies, a state by state guide to the independents, including GTE. It
list thousands and thousands of exchanges with step by step. The last
one I have is from 1987. Very few crossbars are noted in the West. I
understand that Automatic Electric did not make a crossbar. GTE
supposedly relied on makers like International Telephone and Telegraph
(ITT) to supply one when needed. It would have made sense for A.E.
to concentrate making step by step equipment. It's well suited to the
small towns that independent phone companies catered to. Step by step
offices probably have more add on equipment than any other. They need
it to fit in with the increasingly digital world.
32. A good example are touch tones. An SXS office couldn't process
them before, say, the mid 1960's. Now each office must. But step by
step manufactured after this time would have the right circuitry built in.
Coin service is another problem. Converting an office to dial tone first
was costly. And as coin phone signaling changes so must the CO. More
add on equipment needed. Want to implement ACTS? 911? Getting an
electro-mechanical office to implement these features is quite a task. And
while the telcos may want to put in custom calling everywhere, they
have many problems with step by step. Trunking is another matter, too.
Common channel signaling is seemingly bypassed, ignored or badly
implemented throughout thousands of miles of step by step country.
Not all exchanges, after all, have the enabling hardware to do System 7.
I'll cover this more in the next issue.
It's my experience that the most fun with the phone system comes at the
outer edges of it. There are as many hidden doors and gates there as
there are in Alice's Wonderland. But where do they lead? In the next
issue I will continue this discussion on basics. I'll try to cover trunks in
general, some terms on signaling, and the role of the operator and
TSPS.
J. References
(1) Automated coin toll service, or a derivative thereof, is the automated
operator that you get when dialing a 1+ call from most telco payphones.
For instance, if you dial, say, 1+(916) 213-9999 (an imaginary
number), a computer generated voice will come on the line to tell you
how much to deposit. You then hang up. You'll get a good insight into
the rates charged and the kind of coin service an area provides by dialing
the same number from different payphones in different areas. Do the
same with COCOTs. Listen for switch sounds in the background. You
may even be connected to a billable, long distance number without being
charged. That shouldn't happen. But it does sometimes. As Goldstein
says, "Anything is possible." My advice? Go rural. And go GTE.
(2) Douglas-Young, John. "Illustrated Encyclopedic Dictionary of
Electronics. "West Nyak, Parker. 1981. 335 Out of print but worth
looking for. This hardback is a good, one volume dictionary of
electronics. The section on electro-acoustics is great. His wife is Carol
Young who is the author of the readily available "New Penguin
Dictionary." This book, unfortunately, is much harder to understand
and less complete.
(3) Martin, John T."Chilton's Guide to Telephone Installation and
Repair." Radnor, Chilton Book Company. 1985. 5 A great how-to
book. I'm not sure if this edition is still in print but a revised version
should be.
(4) Among others, Schillio, Robert F. 'A Circuit That Stretches Coin
Telephone Service' Bell Laboratories Record. 51:4 (April 1973) 120.
Don't write off these early articles. They provide many clues as to why
things were done in a certain way, even if a particular piece of
equipment is no longer in service or a practice discontinued.
(5) Fike, John L. and George E. Friend. "Understanding Telephone
Electronics". 2d ed. Carmel, SAMS. 1990 16. Now in its third edition,
this book is widely available. You should buy this book. It assumes a
working knowledge of electronics. A beginner can push through most
of it with dedication. The second edition, however, has only a two page
index for a 284 page technical work.
(6) Martin, 53
(7) Strangely, I've seen a normal analog signal referred to as an AC
signal. And tones are often called AC signals. Yet, the only true AC
signal used is the voltage that rings the phone. How can a DTMF pad
use AC signaling when only DC voltage is present? Does AC really
refer, instead, to the shape of an alternating current waveform? An
alternating current is in the shape of a sine wave. Does this explain AC
signaling?
(8) Rey, R.F., ed. "Engineering and Operations in the Bell System". 2d
ed. Murray Hills, N.J. AT&T Bell Laboratories. 1983 373
(9) Staehler, R.E. and W.S. Hayward. Jr. 'Traffic Service Position
System No. 1, Recent Developments: An Overview' The Bell System
Technical Journal. 58:6 (July --August 1979) 111 Tough article but lots
of interesting details. Find a place you can check this out for a week; it's
really too long for photocopying but too essential to let go.
(10) Confalone, B.E., B.W. Rogers and R.J. Thornberry, Jr. 'Calling
Card Service--TSPS Hardware, Software, and Signaling
Implementation' The Bell System Technical Journal. 61:7 (September,
1982) 1676 Another essential. Find a corresponding article in the Bell
System Record if you find the B.S.T.J. too intimidating.
(11) Fike gives a good, basic description of switches. If you want to
bury yourself in the subject then check out G.E Schindler,ed.
"Engineering and Operations in the Bell System: Switching Technology:
1925 -- 1975." Murray Hills, Bell Laboratories. 1982. Or, if you want
something practical, read Agent Steal 'Central Office Operations' 2600:
The Hacker Quarterly. 7:4 (Winter, 1990) 12--21
(12) Schluttenhofer, R.A.'Two-Way Trunks For Package Offices' Bell
Laboratories Record (November, 1965) 402
(13) Sevcik, Richard W. and D. Paul Smith. 'Custom calling comes to
Clarksville (upstate New York)' Bell Laboratories Record. 58:2
(February, 1980) 63. Fascinating article about a little known subject, the
Remote Switching System.
(14) Some may contend that the T1 line is a trunk in this situation and
not a collection of subscriber lines. A trunk, after all, is a circuit
between switches. They are partially correct. A remote unit is not a fully
functional switch. It cannot operate without the central office. It may not
generate its own dial tone. It can be viewed as an extension of the CO
and not as an independent office. A PBX is also a switch. But its lines
to the CO are treated as lines and not trunks. The PBX is not functional
without certain central office features. It is not able , for example, to
pass long distance traffic to the world without the CO. Line and trunk
are often used interchangeably in a discussion of traffic between the
CDO and the central office.
(15) Peterson, Gerald H. "Improving Coin Service For Step-by-Step".
Bell Laboratories Record (February 1974) 41
(16)Rey, 735
-------------------------------------------
5. THE POST PAY COIN LINE
A. Introduction to Post-pay
1. Post-pay coin phones still exist in many rural communities. Little
towns like Jordan Valley, Oregon or Buhl, Idaho are typical. These
phones quite often still take a dime for a local call. Their operation is
simple. You lift the handset. The central office returns a dial tone. You
dial your number. The payphone shorts out the transmitter and the
keypad when your party answers. You now have a few seconds to put
in your dime. This frees up the transmitter so that you can talk. Coins
are not returned unless rejected. A lack of coin return isn't a problem
since you don't put in any money unless your call goes through. You
are often timed out after ten seconds or so if no money is deposited.
You can call the operator without a dime and in most cases 911.
Pranking is supposed to be a problem. Most of the towns I have been in
with post pay, however, have only one or two public phones to begin
with. You would probably be spotted easily if pranking was your
hobby. Post-pay is a nice system. Let's look at it further.
B. History of post-pay
2. The debate over providing post-pay or pre-pay coin service began
after the first installation of a non-attended coin phone in 1899.(1) Coin
first operation was more complex since it had to allow for coin return in
case a call did not go through. The coin phone and the central office
would also need more equipment. Post-pay was simpler but it took up
more of the operator's time. She frequently had to wait until the caller
found the right change so that she could then connect the call. With coin
first, however, the initial deposit was made before the operator came on
the line. The argument against coin first was more serious than
monetary: an operator could not be raised in an emergency without a
deposit. The debate did not last long. Operator time was too valuable to
waste. "(T)raffic holding-time savings"(2) pushed public safety
concerns aside. Fagen contends that from 1906 the Bell System
concentrated on providing coin first, pre-pay operation. Schindler,
however, points out that panel switching systems in the twenties
allowed for dial tone first and coin less calls to "operators, service
codes, and selected 'official numbers'." In any case, coin first or pre-
pay became the rule and the simpler, slower post-pay became the
exception.(3)
C. Post-pay today
3. Post-pay has survived at the outer edges of the phone system, in
little towns and distant villages. It has been that way for a long time.
Rey contends that post-pay operation was chosen for rural service
because of the "long distance between the local community dial office
and the resultant large cost of returning coins on unreturned calls."(4)
This is confusing. Returning coins is not terribly expensive by itself.
Post pay coin phones, for example, do return coins if a coin is invalid.
But pre-pay equipment is more costly than pre-pay. Post-pay is cheap to
install and maintain. It is compatible with the switching equipment at the
end office. As stated before, a payphone is dependent on the equipment
it is tied to. Most post-pay phones are not directly wired to a full
featured central office with a modern switch. They are instead first
connected to a simple CDO.
D. The community dial office
4. A community dial office is an end office that serves a few dozen lines
to perhaps 2000 lines. The last census of the Bell System in 1983
revealed 3,700 of these offices, more than any other kind of switch.(5)
A CDO is a step below the central office in rank and relies on the CO for
many things. It may not, for example, generate its own dial tone. In
many ways the end office acts as a remotely controlled switch. The
switching equipment itself is often the simple but reliable step by step.
Rey predicted that the now defunct Bell System would replace all
CDO's serving under step by step control by 1990. Perhaps the regional
companies did. GTE and other independent phone companies certainly
have not.
5. Community dial offices were first installed in the late 1920's when
direct dialing began replacing operator connected calls. CDO's were
widely deployed over the next forty years. They provided the backbone
of local switching in rural America, or outstate as Bell System lingo
used to put it. We'll look at post-pay in the context of a CDO. But not
all CDO's have post-pay. Many, many of the newer CDO's have pre-
pay service, especially the ones owned by the former bell companies.
Post-pay coin service was a part of CDO design since the beginning.(6)
But the real definition of a CDO is that it relies on a central office for
many functions, not that it provides post-pay. The reason that a CDO
has post-pay is because, usually, the low volume of calls. Such light
traffic might never justify the more expensive pre-pay. And coin
service, like regular subscriber service, is always more expensive in
rural America.
E. The subscriber loop network
6. A post-pay coin phone might be three to eight miles from the dial
office, however, the central office might be dozens and dozens of miles
away and the operator several hundred miles away. Some CDO's and
remotes handle local calls without first going to a central office. But
some may route a call out to the central office and then back through the
CDO. Once the connection is set up the call may be dropped back to the
local switch, freeing up the channel to the central office. This service
requires repeaters, line extenders, extra cable, miles of additional poles
and increased maintenance. Remote payphone lines need additional
equipment on top of that required for routine service. The small number
of coin calls near a community dial office might never justify pre-pay
service. As we will see, a relay to place reverse polarity may be all that's
needed at the CDO. A post-pay line presents nothing special to the dial
office. It is wired to the switching frame along with the other flat rate
phone lines. There are, however, trunking arrangements that have or
had to do with post-pay.
F. Post-pay trunks
7. Much of what is written about CDO's continues the uncertainty over
what is a trunk. Different writers at different times use both terms. This
is unfortunate but not surprising; the line from a CO to a CDO is a
hybrid. Let's use the word trunk for now. So, when talking about the
CDO we have the following: 1) a trunk from the CDO to the central
office, 2) a trunk from the CO to the a non TSPS operator, or, 3) a very
long trunk to a TSPS operator. Signals may be passed on the voice path
or on a data circuit. The thousands of CDO's and the dozens of possible
trunk configurations in rural America result in the greatest hope for the
trunk hopping telephone enthusiast; many of these trunks are still
controlled by tones and not digital signals. I'll introduce trunks in the
next issue when I finish up the discussion on basics. For now, let's
look at what you might find in former Bell System territory. I do not
know enough to comment on a GTE system, although the last two post
pay phones I used were both in independent areas.(7)
Post-pay and RTA
8. Coin trunks are usually provided between the CDO and the central
office to handle coin traffic. A trunking arrangement must also handle
the coin traffic between the CDO and the operator position. This
enables the operator in most cases to know that they are handling a
post-pay call. The traffic service position system (TSPS) was given
many new features in 1979. One important feature was the remote
trunking arrangement or RTA.(8) This was an expensive and
complicated system of trunks designed to bring the benefits of TSPS to
rural areas. A full service operator could now handle rural calls a
thousand miles away. Enabling hardware was installed in dozens of
rural or outstate central offices in the years after. Still, that does not
mean full service. Not for post-pay. You can't make a 1+ call for
instance. That's a limitation of the simple post-pay phone and the
equipment at the CO. Three kinds of trunks were set up for post-pay
calls. Which kind a CO uses depends on what kind of hardware was
purchased for the central office.
(a) Dedicated post-pay trunks. Self explanatory. These channels
are used only for post-pay calls. Might be necessary where the serving
central office does not pass automatic number identification or (ANI) to
the operator. This would be for very simple central offices. Most CO's
put their long distance traffic in digital form. The caller's number is
encoded as well. This data stream is decoded at the operator position.
They then know what number you are calling from. Not passing ANI
means a lack of equipment at the CO or that the trunk can't handle in. In
any case, all long distance calls from the post-pay phone go directly to
the operator. If the calls weren't intercepted then someone could clip
into the lines.
(b) Combined post-pay trunks. These handle regular traffic and
coin traffic. A more efficient use of the trunk. A dedicated channel isn't
left unused all the time, waiting for a call. The central office must have
ANI. This allows TSPS to automatically check a data base of all
American payphone numbers. The operator is then alerted that they are
dealing with a post-pay call by a lamp that is lit on the TSPS console.
The operator must handle the rest of the call. I am unsure of how they
do this. I do know that non-TSPS operators place a 1+ call. If the
connection is made then they tell you to deposit your money.
(c) Combined post-pay trunks with service tone identification.
Signals the operator with a tone. Alerts the operator to a post-pay call.
The central office generates this instead of passing ANI. It seems that
this would be less costly for the local office than providing the
equipment to encode ANI.
9. Not all remote areas can be economically served by the remote
trunking arrangement. Much of independent phone company traffic
goes to a non TSPS operator. Let me know if you know more. Or if
you know whether any of these trunking arrangements still remains.
There have been many changes now that most long distance traffic is on
fiber optic cable. Let's end this introduction to post pay by discussing
its signaling.
G. Post-pay signaling
10. Post-pay signaling is basic, reflecting the simplicity of the
community dial office equipment. There are two essential kinds of
signaling: answer supervision and coin deposit tones. Let's look at
supervision generally and then answer supervision in particular.
Supervision
11. Supervision is a mostly automatic activity of the phone system. It is
a process. Supervision is the way that phone equipment looks for and
responds to, phones going on hook and off hook. It's sometimes called
switch hook supervision. Supervision has also been described as "the
constant monitoring and controlling of the status of a call."(9)This
implies a great deal. Perhaps too much.(10) Since supervision is a
process rather than one simple signal it is a little more difficult to
understand. The language of signaling, in addition, makes this even
harder. You'll read such cryptic phrases as "supervision is passed
through the switching network" or "the call was suped." Let's look at
answer supervision in general.
Answer supervision
12. This happens when we answer the telephone. It is quite a process:
(a) Lifting the handset off the phone causes the switch hook buttons to
rise. This trips a relay inside the set that closes the contacts with the
phone line. This, in turn, connects the phone with the central office;
(b) Voltage now flows in the loop. The phone is now consuming power
like any electrical appliance. This flow is then detected by the switching
equipment;
(c) The central office now stops the ringing voltage. After all, you've
just answered the phone;
(d) The CO then cancels ringback for the calling party. This is the
"ringing" sound that you hear when you call a number. It's
produced and canceled by the CO;
(e) Switching equipment then sets up a connection between both parties
so that conversation can take place.
13. Answer supervision involves many things. The only real signal,
though, is the one made by the phone going off hook. The rest is
automatic. The chief requirement for the central office is to quickly
detect a request for service. This is the "constant monitoring" part of
supervision that we noted earlier. The other part, "the controlling of the
status of the call" should be obvious now; a number of things happen
when we pick up the phone. To repeat, by answering the phone the call
is supervised. Let's look at a variant.
Reverse battery answer supervision
15. Payphones use a type of answer supervision called reverse battery.
Post-pay depends on this almost exclusively. This signal is not peculiar
to coin phones but they do use it for special functions. Reverse battery
can prevent a call from taking place until a coin is deposited in the
payphone. The phone system changes the telephone line's electrical
status to do this. Sound confusing? The terminology is. But the actual
technique is simple, certainly well fitted to the CDO and a post-pay coin
line.
16. Reverse battery is a supervisory signal. It tells the payphone to
disable its transmitter and keypad until a coin is deposited. This prevents
a free call by not allowing any speech or any DTMF signal to be
transmitted until a coin is deposited. This prevents you, for instance,
from retrieving messages on your answering machine with the keypad
on a post pay coin phone. Reverse battery depends on receiving answer
supervision first. The end office detects that the called party has gone
off hook in the normal way. Instead of connecting the two parties,
however, a special relay is tripped at the switching office. This relay
changes the normal electrical condition of the line. Let's take this step by
step.
17. A post-pay coin line has the tip side wire grounded and the ring
side wire closed.(11) This is a little difficult to explain.(12) Both tip and
ring are closed when a normal phone is off hook. Closing the circuit
completes a connection with the central office. With post-pay, the tip is
grounded, usually to a chassis ground. That's just a screw or bolt inside
the payphone housing that a wire runs to. Tip is grounded or shorted
out when the handset is lifted. But the ring side wire is closed, allowing
a connection to the CO with one wire. You are able to dial your number
with this setup.
18. A connection is then made. Answer supervision is returned to the
central office by the called phone. It trips the special relay, the line
circuit relay, at the CO. This causes the tip and ring positions on the
coin phone line to be reversed. It closes the tip side and grounds the ring
side. This change of electrical status is the reverse battery signal. The
pay phone's coin relay senses this change. It's meant to. The relay is
polarity sensitive, engineered to short out the transmitter and keypad. In
other words, it works one way and not another. The line's status returns
to normal after a coin deposit. That's because a coin trips the rate relay .
That frees up the contacts and the line returns to normal.
19. Many electrical appliances won't work well or at all with the wrong
kind or quantity of electricity. Anything with transistors or integrated
circuits, such as a DTMF keypad, are especially vulnerable. Just
changing the voltage from a positive to a negative state is enough to
damage many things. This is fairly easy to understand. What is difficult
to understand, however, is that reverse battery does not mean reverse
voltage or reverse electrical polarity.
20. Freeman(13) and Reeve(14) state that a reverse battery signal uses
negative voltage and not positive. Yet Fike writes about "reversing the
polarity of the tip-ring pair."(15) Reeve further states that in post-pay
signaling "the line circuit reverses the battery polarity applied to the
loop."(16) How can this be? How can one talk about reversing polarity
when all the information shows that there is no change?
21. We usually think of polarity as a positive or negative state. In this
context, however, reverse polarity means that tip and ring have become
reversed, not voltage. Polarity is used in its broadest sense: the
condition of being polar or opposite. Tip and ring positions become
opposed in reverse battery, therefore, reverse polarity refers to a change
in position and not voltage. Reeve confirms this in his last footnote to
the chapter on coin line services. He explains that the keypad inhibit
signal should not be "confused with reverse battery, which is the
reversal of the battery and ground potentials on the tip and ring
leads."(17)
22. So, answer supervision causes reverse battery which prevents a call
until a coin is deposited. Depositing that coin resets the relay which puts
the line back to normal polarity. The only other important group of
signals for post-pay are coin deposit tones.
Coin Deposit Tones
23. A coin deposit tone is a signal that alerts an operator or a piece of
equipment that a certain coin has been put in. There are no specific post-
pay coin deposit tones. Since post pay is not compatible with automated
coin toll service, it could be assumed that dual tone frequency signaling
may not be necessary. But some post-pay phones are tied to TSPS
operators. Coin deposits total on their consoles while they watch and
listen to the tones. The central office probably sends the amount to
TSPS on a data circuit or a channel that connects the two. So, some
post-pay coin lines may demand the current models of telco payphones.
In addition, the newest phones, such as the D model, are far more
reliable than their predecessors. It might be risky to box to the operator
if you don't know which model you're dealing with. Bell System
practice was to systematically upgrade their coin phones over time. I
doubt that any older phones are left in service. Let's quickly look at
some payphone history, to give you an idea of the what might be
possible.
24. Western Electric came out with the 1A1 in 1965,(18) the product of
six years of research. It used a single frequency oscillator to produce a
2200 Hz tone for each coin. A nickel produced a single tone, a dime
two, and a quarter five. In 1968, the "C" type set was introduced. It had
a DTMF pad instead of a rotary dial. The single frequency oscillator
remained. It wasn't until 1979 that Bell Labs introduced a retrofit kit for
the A & C models.(19) This changed them from single frequency to
dual frequency They were now compatible with ACTS. The totalizer, or
coin counter, was changed from an electromechanical device to one
without any moving parts. This was done by using a piezoelectric
transducer, an electronic pad that each coin fell on when it was
deposited. There are three pads, one for each kind of coin. A nickel,
dime or quarter produces a certain amount of current when it falls on its
specific transducer. This current then triggers the oscillator to produce
a tone of 1700 Hz and 2200 Hz. I understand that the current model, the
"D" , is not a retrofit but simply a new phone with the new technology.
And then there was the Western Electric E.C.P.T., but that's another
story.
25. Automatic Electric should use similar coin signaling schemes in
order to be compatible with the rest of the telephone system. But even
the oldest of schemes can be used if the phone company operator places
your call. Three slot coin phones date from the 1920's, although they
were manufactured well into the 1960's. Some of these still exist,
although probably none in the former Bell System territory.(20) Most
three slot phones were modeled after a phone called the Gray pay
station.(21) These were produced by an independent company that
Western Electric later worked with. There were three coin chutes. They
could allow two tones at once if coins were put in at the same time, an
irritation to the operator. A nickel would strike a bronze gong,
confusingly called a bell. The tone was around 1100 Hz. A dime hit this
gong twice. A quarter would hit a helical flat wire, even more
confusingly called a cathedral gong and produce a lower tone of around
800 Hz. These tones were distinct enough for an operator to recognize.
They were not recognizable, however, to most automatic switching
equipment; ACTS, for example, never planned to incorporate the tones
of three slots.
(1) Fagen, M.D., ed. "A History of Engineering and Science in the Bell
System: The Early Years, 1875 -- 1925." New York: Bell Telephone
Laboratories, 1975. 156
(2) Fagen, 155
(3) Dial tone first operation began its reintroduction to the Bell System
in 1966. The reason? Public safety. The tests were in Hartford,
Massachusetts, the site of the first coin telephone. See A.E. Ruppel and
G. Spiro. 'No Dime Needed' Bell Laboratories Record (October, 1969)
296
(4) Rey, R.F., ed. "Engineering and Operations in the Bell System". 2d
ed. Murray Hills, N.J. AT&T Bell Laboratories. 1983. 473
(5) Rey, 461
(6) Schindler, 32
(7) Although the Bell System provided, perhaps, 75% of America's
population with service, they never covered more than half of the
geographical area of the country. This left a huge amount of the United
States, especially the West, with a welter of different operating systems.
Automatic Electric, the manufacturing arm of General Telephone and
Electronics, produced some fascinating and somewhat quirky equipment
over the years, both for wholly owned companies such as GTE of
California and for hundreds of independent telephone companies. Las
Vegas, Santa Barbara, Palm Springs and the Delta country of California
are good areas to investigate as well as much of the rural west. Some
eastern states still have party lines and rudimentary service as well. Feel
free to write to me about your favorite independent provider.
(8) S.M Bauman, R.S. DiPietro, and R.J. Jaeger Jr. "Remote Trunk
Arrangement: Overall Description and Operational Characteristics" Bell
System Technical Journal. 58.6 (July--August 1979) 1119
(9) Rey, 816
(10) Some maintain that addressing, or dialing, is part of supervision.
By dialing a number you control the status of a call. True enough.
Operators do too, however, by asking you to put in more money or to
dial a number again. ACTS controls a great deal of coin calls. Are these
supervisory signals?
(11) Reeve, Whitman D. "Subscriber Loop Signaling and Transmission
Handbook: Analog." New York: Institute of Electrical and Electronics
Engineers. IEEE Press. 1992. 217 A great book. The best, most current
explanation of the local loop. Excellent chapter named Coin Line
Services. Find this book. It's usually checked out. Do an inter-libary
loan if you have to.
(12) Nothing is more frustrating to explain than the various
combinations of tip, ring and ground. But nothing is more important to
understanding coin phone signaling. I put some illustrations in the
second issue that explain this better.
(13) Freeman, Roger. L. "Reference Manual for Telecommunications
Engineering." Wiley Interscience. New York. 1985. 81 Well worth
browsing though. Look for it in the reserve section. Freeman is a well
respected authority.
(14) Reeve, 217
(15) Fike, 193
(16) Reeve, 217
(17) Reeve, 223
(18) Stokes, R.R., 'A Single-Slot Coin Telephone' Bell Laboratories
Record (January, 1966) 20 Details the 1A1, the payphone that became a
standard.
(19) Habib 'Coin Handling Goes Electronic' Bell Laboratories Record
(April, 1979) 95
(20) I used a three slot last year in Jordan Valley, Oregon. It was a beat
up Automatic Electric, with half its armor missing. My 1+ call to Boise
was intercepted by an operator with the, I believe, Telephone Utilities of
Eastern Oregon. It was great, I felt like I was in Mayberry, trying to
place a call to Mount Pilot.
(21) Fagen. M.D. ed., "A History of Engineering and Science in the
Bell System: The Early Years (1875--1925)" 159 The picture of the
three slot phone is nearly identical to the ones that W.E. produced nearly
fifty years later. A.E. types are a little bulkier and rounded on the edges.
And, yes, you should look at Fagen's book, too. It's curiously
subtitled, this 1000 page monster actually covers many things past the
1950's.
More next issue . . . (August)
------------------------------------------------------
7. A CONVERSATION WITH MOTOROLA
In the hardcopy edition I reprinted a Motorola ad from earlier in the
year. The illustration depicts a group of grimly faced emergency
services people. Firefighters, EMTs, doctors and police stare out from
the gloomy looking page. The artwork seems to be done in pencil and
charcoal. I reprint the text of the ad first in quotation marks. My
comments follow.
"ATTENTION: PUBLIC SAFETY ANNOUNCEMENT
Tampering With Motorola's Communication Technology Is Nothing
Short of a Crime
Motorola has been at the forefront of communications technology for
more than 60 years. Today, we offer a greater array of communications
products than ever before. We are proud of our products and the vital
services that they bring to our customers which are of unparalleled
public importance.
Theft of communication services and so-called High-Tech piracy
threaten the entire communication industry's reputation for reliability.
This conduct not only damages the reputation of Motorola, Inc. and the
communication industry, but undermines the very integrity of America's
public and private communications services.
Motorola intends to combat this conduct by aggressively maintaining
and enforcing its rights to its hardware and software technology.
Anyone who has knowledge of illegal activities or has questions
concerning such activities is urged to contact Motorola Inc. immediately
at 1-800-325-4036. Contacts will be kept confidential and may be made
anonymously.
Motorola"
This curious ad has been placed for many months in the three
largest ham radio magazines: CQ, QST and 73 Amateur Radio Today.
I thought at first that Motorola was talking about cell fraud. But how can
a pirated call affect "the very integrity of America's "public and private
communication services"? And why are they advertising in amateur
radio magazines? Are the real hackers in radio? What's going on? The
ad said to call with questions. So I did.
I talked to a Mr. John England. He said the ad had nothing to
do with cell fraud. Instead, it had to do with pirating commercial radio
services, you know, car to car, car to dispatcher, that sort of thing.
England said that they knew about amateurs who, for a price, would set
up a commercial radio and its software to work on emergency services
frequencies. He said that Motorola is working with "all the appropriate
federal agencies" in their investigations. He admitted, however, that no
one had ever been convicted of doing what the ad was concerned with.
He mentioned, somewhat sheepishly, that there were other ways to stop
an activity without imposing a criminal penalty. Like having someone
pay a fine. Oh, really?
Hackers are rotting in jail for nothing more than a low-rent
economic crime or because they supposedly invaded, according to the
most crippled definition possible, someone's electronic privacy. And yet
Motorola and the Feds will negotiate with people who deliberately
interfere with emergency services? Someone who gets in the way of
fire, police or ambulance service should go to jail. But I know of no one
in the hacker community who has ever sought to do such a thing.
Radio amateurs take great pride in a good public image. They do
a great deal of self-policing. Some amateurs have done stupid, criminal
things, like making false distress calls. But rarely do they go to jail.
Licenses are pulled and fines imposed. I suppose that Motorola could be
trying to scare people off. England said that the "bad news bears know
exactly who they are." A proactive approach is always good, generally.
I think though, that you won't see a warning from Motorola about
experimenting with cellular phones. If there's trouble it seems more
likely that the Secret Service will be involved, that you will be arrested
and that you will go to jail. I doubt that much negotiating will go on,
even if you were just calling a mailbox. Sounds like you're safer
playing with the police. Go figure.
-----------------------------------------
7. THE GTE RTSS PHONE
In this article I reproduced an ad for a General Telephone and
Electronics Red Telephone Switching System phone. I asked for help in
identifying some of the strange acronyms and abbreviations. I ask for
comments from the readers of the electronic version as well. The ad is a
photograph of the phone with text. Yes, the phone is a nice red color.
My magazine is, unfortunately, in black and white. Still, you may find
the ad in 'Air Force' magazine and some other mainstream publications.
It looks similar to a generic ISDN phone but with the Autovon keys and
with some sort of LCD dis
play. The display looks to be about 2" by 4".
Here's the text:
Look where you can go with One GTE RTSS phone
ANDVT
AUTOVON
CLASS A DIALLINE
DEFENSE SWITCHED NETWORK
JCSCAN
KG-81/94, TRUNKS & MULTIPLE REMOTE SUBSCRIBER UNIT
KY-3 AUTOSEVOCOM
LAND MOBILE RADIO
LONG-HAUL HOTLINES
ON-BASE HOTLINES
RED SWITCH NETWORK
SATCOM RADIO
STU-II KY-71/ PARKHILL KY-65/75
STU III
TACTICAL GATEWAY DSVT KY-68
TACTICAL SWITCH DROP
UHF RADIO
VHF RADIO
With GTE's Red Telephone Switching System (RTSS), a single
phone gives you total Red/Black voice communications access to all
these places . . . with unequalled security. It also provides robust
connectivity and interoperability with other existing and future secure
voice systems - - tactical, strategic, and commercial. A 20-year life-cycle
support program is backed by a proven GTE worldwide field support
and logistics system. You, too, can order RTSS under Contract No.
F34608-88-D0007 from the DoD through HQ EID, Tinker AFB,
Oklahoma.
If you use more than one phone for secure/non-secure
communications, you haven't been authorized RTSS. -----------------
GTE Government Systems"
This ad details an exciting looking phone. I know nothing about it. Let
me know if you can help by filling in the details. I'll get the guessing
game going. Much has been written about Autovon. It utilizes the four
right hand buttons: flash overide, flash, intercept and priority. These
correspond to the four extra tones that are built into most DTMF IC's.
These silver box tones are not often used by most telcos but they are
used by Autovon to prioritize phone calls when they are first placed.
Anyway, the Red Switch Network would have to piggyback onto
Autovon if it is being included in this phone. Wouldn't it? And what are
Red/Black voice communications? One of the colors probably stands for
secure voice communications. And I mean secure. It's likely that an
imbedded chip in the phone does the NSA certified encryption. So, you
have a secure line immediately with no need to interface with anything
else. As such, it is probably classified as a "controlled cryptographic
item." It probably allows only one person to speak at a time when it's in
the secure mode.
KY-3 AUTOSEVOCOM should stand for automatically secure voice
communications. Comsec stands for the obvious: secure
communication. There are, apparently, many forms of comsec. Some of
them are KY-57, ANDVT, and KG-84. The field radio receiving this
traffic is called, I think, a processor. Motorola makes a unit called the
Sunburst II processor.
---------------------
8. CALIFORNIA TOLL FRAUD LAW
Many laws relate to telephones. Here's the text of one along with my
comments. (This is far less confusing in the hard copy edition since I
am able to italicize my comments.) Broad ranging code sections give the
police the power to move against nearly any one at any time. In reality,
the law is mostly used against high profile criminals, gangs of
criminals, people who get caught red handed and people who can't
afford to challenge bad law.
California Penal Code Section 502.7 Obtaining telephone or telegraph
service by fraud
"(a) Any person who knowingly, willfully, and with intent to defraud a
person providing telephone or telegraph service, avoids or attempts to
avoid, or aids, abets or causes another to avoid the lawful charge, in
whole or in part, for telephone or telegraph service by any of the
following means is guilty of a misdemeanor or a felony, except as
provided in subdivision (g): . . ."
(The main clause. Rather generic on purpose. You may be charged with
this at first if you are arrested for something telephonic. The initial
charge is the booking charge. The DA decides the specific charges later,
often making it more detailed with the help of the rest of this code
section.)
"(1) By charging the service to an existing telephone number or
credit card number without the authority of the subscriber thereto or the
lawful holder thereof. . . ."
(Prohibits telephone theft by wrongful billing or credit card fraud.)
"(2) By charging the service to a non-existent telephone number
or credit card number, or to a number that associated with telephone
service which is suspended or terminated, or to a revoked or canceled
(as distinguished from expired) credit card number, notice of the
suspension, termination, revocation, or cancellation of the telephone
service or credit card having been given to the subscriber thereto or the
holder thereof. . ."
(Legitimate card holders can't be jailed for mistakenly using an expired
card. Or, at least, they're not supposed to be. There's not much risk of
this provision being abused since most cards are canceled automatically
upon expiration.)
"(3) By use of a code, prearranged scheme, or other similar
stratagem or device whereby the person, in effect, sends or receives
information. . ."
(I am not sure what this refers to. Can anyone give me an example of
what the legislature meant by this?)
"(4) By rearranging, tampering with, or making connection with
telephone or telegraph facilities or equipment, whether physically,
electrically, acoustically, inductively, or otherwise, or by using
telephone or telegraph service with knowledge or reason to believe that
the rearrangement, tampering, or connection existed at the time."
(Prohibits fraud by technical means. What's so unfortunate is that credit
card thieves are put into the same section as hackers. This might explain
some law enforcement paranoia, since the two groups of people fall
under the same section. Tone generators would probably be prohibited
by this subsection.)
"(5) By using any other deception, false pretense, trick, scheme,
device, conspiracy, or means, including the fraudulent use of altered or
stolen information."
(Legitimate means to us are probably tricks and schemes to the
uninformed. Does an Internet dialout mean anything to an assistant
district attorney who intends, someday, to log onto Prodigy?)
"(b) Any person who does either of the following is guilty of a
misdemeanor or a felony, except as provided in subdivision (g):
"(1) Makes, possesses, sells, gives, or otherwise transfers to
another, or offers or advertises any instrument, apparatus, or device
with intent to use it with knowledge or reason to believe it is intended to
be used to avoid any lawful telephone or telegraph charge or to conceal
the existence or place of origin or destination of any telephone or
telegraph message. . ."
(The first part of this paragraph prohibits the selling or distributing of
an assembled toll fraud device. The second part is a little cryptic. It
refers to a device that can mask a caller's location. Sounds like a call
forwarding device. I'll have to look into the committee reports to see
what tool so spooked the legislature that they made it illegal.)
"(2) Sells, gives, or otherwise transfers to another, or offers or
advertises plans or instructions for making or assembling an instrument,
apparatus, or device described in paragraph (1) of this subdivision with
knowledge or reason to believe that they may be used to make or
assemble the device."
(Prohibits distributing plans for a toll fraud device. You can't even give
them away. But it's selective. An issue of Harper's was pulled off
shelves in the early 1970's for an article on blue boxing. And yet 2600
did not get their summer 1993 edition pulled in California because of the
red box schematic. Tap was shut down, I believe, for printing articles
on toll fraud devices. And yes, you can buy books on how to make C-
4, modify an AR-15 to fire on full auto, or learn how to cut the brake
lines on a bus. Just look in the back of Soldier of Fortune or order a
catalog from Paladin Press. In fact, I could publish a magazine called
KILL!, containing articles on how to beat, torture and maim people in
dozens of ways. And it would be legal. So long as I didn't put in a red
box schematic. Do you think any telco executive would worry about my
new zine? Of course not, in fact, they'd probably try to sell me an 800
number for my new business. The concern of the legislature and the
telco is about profits and the control of technology. Don't believe
anything else.)
"(c) Any person who publishes the number or code of an existing,
canceled, revoked expired, or nonexistent (!) credit card, or the
numbering or coding which is employed in the issuing of credit cards
with the intent that it be used or with the knowledge or the reason that it
will be used to avoid the payment of any lawful telephone or telegraph
bill is guilty of a misdemeanor. Subdivision (g) shall not apply to this
subdivision. As used in this section publishes means the communication
of information to any one or more persons, either orally, in person or by
telephone, radio, or television, or electronic means, including, but not
limited to, a bulletin board system, or in a writing of any kind, including
without limitation, a letter or memorandum, circular or handbill,
newspaper, or magazine article, or book."
(Okay, we get it. It's illegal to talk about calling card numbers if you
intend to defraud a telephone company. It's even illegal to talk about
something that doesn't exist. But what if you are talking and writing
about numbering schemes because you are simply interested? Intent
must be proved by act. There has to be some overt evidence that you
intend to defraud. Usually. Nowadays, I think that mere possession of
such material will get you in trouble.)
"(d) Any person who is the issuee of a calling card, credit card, calling
code, or any other means or device for the legal use of
telecommunications services and who receives anything of value for
knowingly allowing another person to use the means or device in order
to fraudulently obtain telecommunications services is guilty of a
misdemeanor or a felony, except as provided in subdivision (g)."
(This makes it illegal for telco people to let someone else use their
equipment, codes or credit cards.)
"(e) Subdivision (a) applies when the telephone or telegraph
communication involved either originates or terminates, in this state, or
when the charges for services would have been billable, in normal
course, by a person providing telephone or telegraph service in this
state, but for the fact that the charge was avoided, or attempted to be
avoided, by one or more of the means set forth in subdivision (a)."
"(g) Theft of any telephone or telegraph services under this section by a
person who has a prior misdemeanor or felony conviction for theft of
services under this section within the past five years, is a felony."
(A felony if you have a prior under this law. You go to state prison for
at least a year. Misdemeanors can't be punished by more than a year in a
county jail.)
"(h) Any person or telephone company defrauded by any acts prohibited
under this section shall be entitled to restitution for the entire amount of
the charges avoided from any person or persons convicted under this
section."
"(i) Any instrument, apparatus, device, plans, instructions, or written
publication described in subdivision (b) or (c) may be seized under
warrant or incident to a lawful arrest, and, upon the conviction of a
person for violation of subdivision (a), (b), or (c), the instrument,
apparatus, device, plans, instructions, or written publication may be
destroyed as contraband by the sheriff of the county in which the person
was convicted or turned over to the person providing telephone or
telegraph service in the territory in which it was seized."
(The police can seize anything that might be used in a prosecution. They
can do it with a warrant or they can grab it if they take you in for, say,
loitering. You have no hope that the police will return contraband.
None. Material that may or may not be contraband will probably be
kept as the investigation moves forward. There is little hope that
anything suspicious will be returned until after trial. It's possible
evidence, after all. You could be waiting for many, many months or
more.)
"(j) Any computer, computer system, computer network, or any
software or data, owned by the defendant, which is used during the
commission of any public offense described in this section or any
computer, owned by the defendant, which is used as a repository for the
storage of software or data illegally obtained in violation of this section
shall be subject to forfeiture."
(Hope you can loose your computer while the Powers That Be decide
your fate. With the proper warrant they can confiscate everything. You
then chew your fingernails for months while they search your files and
decide on strategy. Maybe they'll move forward with your case. Maybe
not. Securely encrypting your most sensitive files would seem wise. A
case would have to be built on other things. But if they do issue a
warrant then you have probably been watched for some time. So, they
may have other evidence. And they'll be mad as hell about not breaking
a particular file. They may become more determined. It's up to you and
your lawyer to figure out how to proceed.
Some hackers are thieves but not all thieves are hackers. I understand
that the legislature wanted to have one code section just for toll fraud.
But experimenting with the phone system is a far different thing than
seeking to exploit it. Anyone who thinks that a red box tone can hurt the
security of the network or cause damage to a switch is a fool or a
corporate liar. In the next issue I'll reprint Penal Code Section 502.8,
the law prohibiting cellular phone fraud.)
--------------------------------------
9. PRIVATE LINE INFORMATION
The Rates
A full page ad costs $75.00. A half page costs $37.50. A quarter page
costs $18.75. This applies to the first newsstand edition which will
come out in January, 1995. There is no requirement to be a subscriber
in order to advertise. You can reserve this rate for all of 1995 by placing
an ad in January's edition. You don't need to pay in advance to reserve;
just tell me that you intend to do it. Payment and camera ready art work
for the first month's advertisements are due one month before each issue
comes out. A photocopy of the page that the ad is on will be sent out
once a particular issue is completed. Classified ads of 25 words or less
are free to subscribers. Comments? Corrections?
e-mail Tom Farley -- privateline@delphi.com THANK YOU!
