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- **********************************
- * The TMC Primer *
- *--------------------------------*
- * Written by: Cap'n Crax *
- *--------------------------------*
- * December 17, 1986 *
- **********************************
-
-
- This file was originally intended to be a "data file" of info on TMC ports,
- formulas, etc, but I decided that it would serve a better use as a "tutorial"
- of sorts. But first a bit of background info...
-
- Who is TMC?
-
- TMC (TeleMarketing Communications) is a long distance service serving all 50
- states. While not as well known as MCI or Sprint, they are a fairly large
- company. They are capable of setting up business communications systems,
- PBX's, and residential service. Unlike most LDC's, however, they operate on a
- "franchise" basis, which means that each franchise of the company has little
- information about any other franchise, although they do use the same lines and
- the same type of equipment.
-
- So, what can they do for me?
-
- Well, for most of us, TMC offers many new potentials for abuse. One of the
- primary weak points of the company is the code formats that they decided to
- use. Codes on all TMC ports are seven digits. If they were generated
- randomly, this would be a reasonably secure system from sequential code
- hacking. But TMC doesn't use random codes. Instead, they use a checksum based
- formula system, with different formulas on each port. I assume that this is
- because they wanted a wide displacement of the codes over the seven-digit
- series, so that a sequential code hacker wouldn't be able to get 2 or 3 good
- codes in a row. Or perhaps they are just very stupid. In any case, it's
- interesting that they seem to have never thought of what could happen if
- anyone ever managed to figure out any of these formulas. Anyway, that's what
- this file is about.
-
- Great! What else can you tell me?
-
- Well, TMC seems to use some form of the Dimension PBX system for their billing
- system (Their ads say that the switching equipment is digital). This makes
- TMC ports easily identifiable by the "Hi-Lo" bad code siren. For those who
- worry about such things, TMC is one of the "safer" companies to use. This is
- largely because, unlike "unified" companies like MCI, TMC franchises don't
- really care if another franchise is losing money. Since each franchise is
- independent of all others, there are many 800 ports, one for each franchise.
- If you use an out-of-state 800 port, you are free from such worries as ANI,
- which I have never perceived as a major threat to the code-user anyway. Also,
- TMC offers lots of opportunities for the aspiring security consultant
- (hehehe).
-
- Ok, so where's some real info?
-
- Right here. I am going to explain as much about TMC hacking as I can manage,
- without actually handing out codes. First, an example port. The example I am
- using is the 800 port for Louisville, KY.
-
- 1-800-626-9600
-
- This is the port. If you are not familiar with TMC, you may want to call it
- to see what it sounds like. So let's say you call it and recognize it as a
- TMC. What next? Well, a good bet would be to run a standard "code-hack"
- program on it... Set it for seven digits, 1+ the number, and note that TMC
- codes start with 0 on more than 50% of the ports I have seen. So let's say
- that you then get this list of (fictional) codes...
-
- 0347589
- 0347889
- 0348179
- 0350358
- 0355408
-
- At first glance, this may look like a series of "random" numbers. But, look
- closer. These numbers are based on a checksum. It is as follows...
-
- Code Format: 03xabcy
- x+y=13
- (In the first code, x=4 and y=9, and, of course, 4+9=13)
- a+c=15
- (Here, a=7 and c=8, and 7+8=15)
- b=1 to 9
- (Digit "b" is unrelated to the rest of the numbers. It could, for example, be
- varied from 1-9 to possibly find more working codes)
-
- Also note that 0+5 would equal 15, since the 0 is really a 10. Really!
-
- Please note that the above formula is only fictional. I wouldn't want to
- possibly cause loss to TMC by giving away codes on their system!
-
- Is that all?
-
- No, of course not. TMC, in their love of telecom enthusiasts, has also put an
- additional prize in the Krackerjack box. The vast majority of TMC ports have
- "Outside Line" codes, which is a 2 or 3 digit number, that, when entered after
- certain codes, will give an AT&T dialtone. This is apparently a holdover from
- the fact that they are using PBX equipment. Anyway, if anyone is asking why
- you'd want an AT&T dialtone, (does anyone need to ask?) it will allow
- unrestricted calling. This, of course, means 976's, 900's, Alliance
- Teleconf., international calling, etc... Naturally, I can't list any of these,
- but I can say that if it is 2 digits, it would start with any number from 2-9
- and end in 8 or 9. If it is three digits, it will almost always start with 6,
- and be followed by any two digits. Some possible outside line codes would be
- 59, 69, 89, 99, 626, 636, 628, etc... These, of course, are only examples of
- possible codes. As I mentioned, these O/S line codes are entered after the
- seven digit code. The O/S line codes only work after certain 7-digit codes,
- and from my experience, the 7-digit codes that they work with normally can't
- be used for the usual 7 digits+1+number dialing. I can find no apparent
- pattern to the codes that they do work with, so you will have to find them by
- trial-and-error.
-
- What, you want more?
-
- Ok, well, here's a few 800 ports...
-
- 1-800-433-1440 1-800-227-0073 1-800-331-9922 1-800-451-2300
- 1-800-354-9379 1-800-248-4200 1-800-531-5084 1-800-351-9800
-
- Closing.
-
- Please note that this article is only intended as an overview of TMC and why
- they would/wouldn't be a good choice for your long distance needs. And
- goodness me, don't use any of this information in an illegal way!
-
-