Alternate Long Distance (March, 1984) ------------------------------------- First of a persistent series how the companies work and a guide to MCI SWAGIMA. That's the word that National Public Radio uses to describe long-distance services. It stands for SBS (or Skyline), Western Union (or Metrofone), Allnet (or Combined Network Services), GTE Sprint, ITT, MCI, and of course AT&T. And there are many more, each of which will eventually be covered in our pages. Right now though, we would like to give you an idea of what these systems are and how they work. Except for AT&T, all of the above systems work in a fairly similar manner. (This will be changing very soon and very dramatically under the terms of the Bell divestiture.) Each system has its own series of networks, i.e. landlines, lines leased from AT&T, microwave relays, satellite links, etc. They each have local city access numbers, although some like Allnet and MCI have special ways of using a "travel" service by dialing a special number, while Sprint uses a "travelcode" to access nodes outside the subscriber's city. On others, like Metrofone, you can use the same authorization code from any of their access points. A long-distance telephone company consists of four major parts: You have your input - that is, a local access number or a toll-free "800" number to access the system. When you do this, a device called a "switch" answers, giving you the familiar computer dial tone. When you enter your authorization code and destination number, you are routed over their network. The heart of the system is the controlling system, which includes the "switch." This is the computer that checks the authorization code, has provisions for time-of-day restrictions, travelcodes, accounting codes, and the like. They have a few provisions, which the long-distance services don't appear to use, such as the infamous "speed number" recording, which was a favorite of many phone phreaks (for reasons you'll soon know if you don't already). The system checks to see if the location being dialed is on the network, and acts accordingly. It makes a log of numbers called, the authorization code, and time usage, which is stored on a word processing tape and then read by another system for billing. Some companies charge in one minute increments, although the system has the capability to record time usage in 6-second increments. There are quite a few different systems in use today. A couple of the most common ones are made by Northern Telecommunications, which is based in Dallas, Texas. Another company that sells similar equipment is Rockwell Wescom. MCI allegedly is in the process of buying new switches from them, and they will be installed by Dynacomp Telecommunications, also based in Dallas. Microwave Links Most of the low-cost services, at one point or another, use microwave antennas to transmit calls. Each microwave station is located about 30 miles from each other to make up for the curvature of the earth since microwaves travel in a straight line. Each of these stations has four dishes (at least). One dish is used to receive from a previous station and one is used to transmit to that station. The other two dishes do the same thing to the destination station - one receives and one transmits. So if you make a call 3,000 miles away, you may wind up going through 100 different microwave stations, many of which you can see next to major highways. This is how the alternate long-distance companies manage to charge less than AT&T; they use their own systems. But this is also why, in many instances, the sound quality is poorer on the alternate services. Remember, a chain of microwave towers is only as strong as its weakest connection. A Look at MCI MCI (Microwave Communications Inc.) was the first new kid on the block, way back in 1967 when the idea of an alternate phone service was almost unheard of and practically illegal. MCI was first used solely by businesses who wanted to communicate between the cities of Chicago and Cleveland. That was it. And even with this amazingly limited system, MCI ran into problems with AT&T, who didn't want anybody trying to do what they did. Lawsuits followed, with MCI eventually getting a promise of eventual equal access to the AT&T network. In fact, MCI's legal action is largely considered to be one of the motivating factors behind the breakup of the Bell monopoly. Now MCI is the biggest of the alternate services (they have well over a million subscribers at present, having opened their doors to residential customers a mere five years ago) and also one of the hardest to penetrate. The system has 5-digit codes that are entered before the 10-digit phone number, a total of 15 digits. But these codes only work from one location, making it rather unlikely to find one by guesswork. If you want to use the system from another city, you have to sign up for MCI "credit card" service, which costs an additional $5 a month (on top of an initial $5 a month charge for the regular service). Here you get a list of 48 phone numbers around the country and a 7-digit code, which can be used from any one of them. Most code seekers prefer scanning the "credit card" numbers since more numbers work overall. However, a strong argument can often be heard in favor of the 5-digit numbers that are located in densely populated areas like Los Angeles or New York. Naturally, the odds of finding something increase under those circumstances. No Proven Method for Finding Codes MCI, being the oldest of the companies, has learned quite a bit in that time. Therefore, no major bugs are still crawling around on their system. Hackers have many theories on number patterns, of course. For example, numbers like 22222 or 12345 tend not to work. In other words, your guess is as good as ours. As far as what they do when they know a code is being abused, MCI seems to be more interested in changing the code rather than laying a trap, as other companies have been known to do. Of course, this doesn't mean that they're incapable of doing such a thing. MCI Features The MCI tone sounds like all the others (a hollowish, medium-pitched, steady tone), but it has its own set of recordings, depending on what you do to it. If you enter an invalid code, you'll hear a mechanical female say: "THEE AUTHORIZATION CODE YOU HAVE DIALED IS INVALID TWO ZERO THREE" and then an ESS reorder that trips over itself (listen to it and you'll understand). If you dial someplace you're not supposed to call (for whatever reasons), you'll hear: "THEE NUMBER YOU HAVE DIALED IS NOT ON THE NETWORK TWO ZERO THREE" and the reorder. Each MCI dial-up has its own 3-digit identity code and they tend to be similar the closer together they are. Many businesses are installing MCI "dedicated lines" in their offices, which takes away the task of having to dial the MCI access number. In addition, you don't have to enter an authorization code and you don't even have to have touch tones. You simply pick up the phone and there's your MCI dial tone! According to MCI, you have to make at least $75 worth of out-of-state calls per month for this system to pay off. Of course, you can't access operators, directory assistance, 800 numbers, and that sort of thing because 1) MCI doesn't support any of those services and 2) they're certainly not going to let you connect to something they can't charge you for. Of course, if you know what you're doing, you can route calls in such a way that numbers that aren't supposed to go through for you will work, and God knows where it finally shows up! This doesn't involve extra codes, blasting the line with tones, or anything overly suspicious. All you need is the right combination of area codes. Now this has been proven to work with MCI dedicated lines; it's rumored to work on dial-ups as well... Finally, MCI is starting to offer its own phone booths at airports, which we'll report on as soon as we find one. And of course, there's MCI Mail, an electronic overnight mail service started up last fall, which hackers are currently probing.