STATION ID - 7047/3.12 9x Datakit Network FOR OFFICIAL USE ONLY This is a 9x system, restricted to authorized persons and for official 9x business only. Anyone using this system, network or data is subject to being monitored at any time for system administration and for identifying unauthorized users or system misuse. Anyone using this system expressly consents to such monitoring and is advised that any evidence of criminal activity revealed through such monitoring may be provided to law enforcement for prosecution. "DATU for Dummies" ... a brief introduction to the powers of DATU, written for the person who has never even heard of one. Well, before I even start, I'd like to shout that phreaking ain't dead yet. It's mutated, yeh, but so has your bone structure and so has the human genome. They still exist, and so does phreaking. A big foo if you don't agree with me. If you do, contact me somehow (telepathy works well). With that in mind, and the satisfying feeling that 'gee, I just learned something today, and I want to tell yall about it', I'm going to edjuhmicate you about DATU. All the info in this article is 100% guaranteed, cause it came from where it counts - good ole Ma Bell and her Technicians Guide, which I'd recommend that you acquire, if you haven't already. It costs a buck eighty five, and can be acquired from your local ma bell ;) or POES (the internal bell document ordering system, for those of you who don't know). If you've never heard of DATU, it stands for Direct Access Test Unit. Hekimian labs (www.hekimian.com) previously marketed DATU, but I believe that they have discontinued it in favor of newer testing systems. Not to fear! It's still one of the most widely used dial up test boards, at least it is on the east coast. What can you do with DATU? Well, you can perform lots of tests with it. It can be used to locate pairs ala Fox-Hound, if you have an inductive amplifier, it can be used to make your neighbor sound like Darth Vader when he uses the phone, it can even be used to remotely short out lines (a kind of temporary disconnect). You can perform busy line verifications, to find out if your neighbor really is on the phone or if his line is 'troubled', and you can inject a 577Hz tone into any line within the scope of the DATU. For the curious, the physical DATU device is nothing more than a printed wiring card, located at the CO, which allows you to dial in and run tests on a trunk. It is connected to a No Test trunk, for those of you that care/know. If you haven't picked up on it already, the DATU is a dialup, analog device with voice menus. When you call a DATU, you'll hear a steady tone. If you sit there for 7 seconds without entering the access code, it'll disconnect automatically and wait for the next call. One important thing to remember when playing with this: when the DATU is in use, it is busy. In use meaning performing any sort of test, even if you've hung up and ordered it to make your neighbor sound like darth for the next ten minutes. So, use common sense when you play with it -- bell needs this thing too, so try and avoid office hours in your experimentation or they might notice you. Yes, I mentioned the necessity of an access code. When you dial up and hear the tone, you enter a four digit access code which is usually very easily guessable (2222, 5555, 1234, etc, etc). After entering the code, you wait a few seconds, until you get a nasty voice prompt. The nasty voice will say 'Dial seven digit subscriber line number'. This, if it's not obvious enough, means to enter the phone number (sans area code) of the line you want to test. The DATU can only operate on lines which originate at its particular central office. If you enter a number which is outside of its control, you will receive an error message, 'Invalid prefix'. After the error message, you will receive a tone again, at which point you can hang up or try another number. If at any point in your transactions with the DATU more than seven seconds elapses between digits, the DATU will automatically hang up and reset. Two notes regarding hacking the code itself: if you enter the correct code, you will immediately hear the tone resume. If you enter an incorrect code, you will hear nothing but silence, followed, after a long break, by a *click* as the DATU hangs up on you. Now the DATU will give you one of two responses, either 'OK', or 'Busy Line'. In the first case, you can use the full range of DATU functions, including all the intrusive ones. If however the line is busy, only the least intrusive tests can be performed, the low level tone injection and the audio monitor/BLV. The tests are selected by dialing the 'test code' which they've been assigned. I've reproduced the applications chart for all of the DATU tests at the end of this article, directly from the Technician Guide Book. Below are the test functions, along with their availability. Function/Test Code Can use on 'OK'? Can use on 'Busy Line'? m00m00m00m00m00m00 m00m00m00m00m00m m00m00m00m00m00m00m00m0 Audio monitor/"2" Hell yeah Hell yeah Short to Ground/"3" Hell yeah Hell no High Level Tone/"4" Hell yeah Hell no Low Level Tone/"5" Hell yeah Hell yeah Open Line/"6" Hell yeah Hell no Short Line/"7" Hell yeah Hell no Say Menu/"8" Hell yeah Hell yeah After selecting the test, it will be held for as long as you remain on the line, up to a maximum of ten minutes per test, at which point the DATU will disconnect you. You can order the DATU to hold the test after you disconnect by pressing the '*' key after starting it. By pressing '*', you order the DATU to hold the test for 5 minutes. By suffixing the '*' with a number between 1 thru 9, 0 for 10 minutes, you order the DATU to hold the test for X minutes, X being the number you entered. You can also change the line you are working on, do this by pressing the '#' key followed by the seven digit number of the line to switch to. You may have seen the audio monitor function and thought 'hey, now i can eavesdrop on Fred'. Well, you can't. If you happened to use it while fred was on the phone, you'd hear a bunch of scrambled crap. Traffic on busy lines is scrambled to thwart perverts like you ;). Its really only good for finding out whether or not fred is on the phone. The low level test tone, option number 5, is the only test you can perform if the DATU returned 'Busy Line'. The only one other than number 2, audio monitor, that is. It basically makes anyone on the phone sound like Darth Vader. What it really does is inject a low level 577Hz tracing tone into the line. This tone is interrupted four times per second. The tech guide states that it 'can only be heard with one side placed on ground' (Tech Guide, page 7.3-5). You can use this, say, if you are at a big mess of wires (ie a box), looking for freds pair. You call up the DATU on some random pair, find out that fred is on the phone, and then enter '5' to activate the low level tone on freds line. Then you hit * and hang up, leaving yourself with 5 minutes to check all the pairs for a this tone. When you've found the tone, you've found fred. It's useful to use an inductive amp for this, that way fred never notices a thing except some pitch alteration. It's just like a Fox/Hound thing. The high level tone test is exactly the same, except with a more audible tone. It is preferable for locating a pair. If fred isn't on the phone, go high level. For reference, the high level tone is also a 557Hz tone, interrupted 4 times a second, for identification. However, one side need not be placed on ground in order to detect it. That's the only major difference between the two. Short to ground is also interesting. With this function, the ring and tip wires of the pair being tested are physically shorted at the CO. This is useful to check the resistance/load between any arbitrarily chosen point on the pair and the central office. Needless to say, this renders the pair unusable for the duration of the test. Open line, option 6, also renders the pair unusable. When you select open line, the battery is shut off on the line, and ground is disconnected. This somewhat simulates what would happen if there was a blackout at the CO, as the line is completely dead, with no power whatsoever. However, Bell reccommends, in the Technicians Guide, against using this as a simulation of blackout. I don't know why, but they do. Maybe the short duration has something to do with it, as DATU limits the test to, at most, 10 minutes. 'Say menu', option number 8, needs no real explanation. When it is selected, the DATU will list off which tests it can perform on the line. Not too complicated, eh? With appropriate test gear, you can do all kinds of analyses on a pair with the aid of DATU. However, things like that are beyond the scope of this article. With the information I've given you, you should be able to figure the rest out for yourself. Well, that's really all that there is to say that's directly related to DATU. I'm sure that you can find some interesting uses for it, in fact, I hope that you do. If you liked this article, drop me an email. My current address is mrnobodyNO@SPAMbitches.org. Take out the 'NO' and the 'SPAM', please. Also if you don't get a response from that address in one or two days, try spacetoadNO@SPAMhotmail.com. Same deal with that address regarding 'NO' and 'SPAM'. Phreaking isn't dead yet; lets keep it alive. So what if the older dudes nailed bell down, there're still plenty of us who haven't, for whom its just as much of an adventure. And plus, there're still plenty of cool things to play with. mrn. ATyP/100% original, 100% unstoppable IMF. ps- if you're on the east coast, definitely drop me a line, even more definitely if you found this useful. moOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOo|oOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOm Addendum -------- This chart may come in handy as a quick reference, it is excerpted directly from the Technicians Guide, page 7.3-4. Applications Situation Function m00m00m00 m00m00m0 Verify busy line Audio Monitor Locating pair in a terminal High Level Tone Identify pair when line busy Looking for one side open Low Level Tone Locating pair in cable Locating faults (grd, shunt, X's etc.) *Do Not consider this conditio- Open Line ning for breakdown* Reading resistance back to CO Short Line Looking for open pair To test loop balance Short to Ground moOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOo|oOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOoOm Bibliography "Technicians Guide Book" Rev. August 15,1991, Pub. by Bell Atlantic/Diamond State Telephone. No ISBN or ISSN. http://9x.tc - Spreading HP in the new millenium