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--------------------------------------------------- PRIVATE LINE: A JOURNAL OF INQUIRY INTO THE TELEPHONE SYSTEM JUNE 1994: VOLUME 1, NUMBER 1 ----------------------------------------------------- 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 ---------------------------------------------------- 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. ------------------------------------------------------- 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 --------------------------------------------------------- 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 ------------------------------------------------------ 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 display. 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!