How Ma Bell Works by the Jolly Roger In this article, I will first describe the termination, wiring, and terminal hardware most commonly used in the Bell system, and I will include section on methods of using them. ------------- LOCAL NETWORK ------------- The local telephone network between the central office/exchange and the telephone subscribers can be briefly described as follows: From the central office (or local exchange) of a certain prefix(es), underground area trunks go to each area that has that prefix (Usually more than one prefix per area.) At every few streets or tract areas, the underground cables surface. They then go to the telephone pole (or back underground, depending on the area) and then to the subsribers house (or in the case of an apartment building or mutliline business, to a splitter or dis- tribution box/panel). Now that we have the basics, I'll try and go in-depth on the subject. ------------------ UNDERGROUND CABLES ------------------ These are sometimes inter-office trunks, but usually in a residential area they are trunk lines that go to bridging heads or distribution cases. The cables are about 2-3 inches thick (varies), and are either in a metal or pvc-type pipe (or similiar). Rarely (maybe not in some remote rural areas) are the cables just 'alone' in the ground. Instead they are usually in an underground cement tunnel (resembles a small sewer or storm- drain.) The manholes are >heavy< and will say 'Bell system' on them. they can be opened with a 1/2 inch wide crowbar (Hookside) inserted in the top rectangular hole. There are ladder rungs to help you climb down. You will see the cable pipes on the wall, with the blue and white striped one being the inter-office trunk (at least in my area). The others are local lines, and are usually marked or color coded. There is almost always a posted color code chart on the wall, not to mention Telco manuals de- scribing the cables and terminals, so I need not get into detail. Also, there is usually some kind of test equipment, and often Bell test sets are left in there. -------------- BRIDGING HEADS -------------- The innocent-looking grayish-green boxes. These can be either trunk bridges or bridging for residences. The major trunk bridging heads are usually larger, and they have the 'Western Electric' logo at the bottom, whereas the normal bridging heads (which may be different in some areas-depending on the company you are served by. GTE B.H.'s look slightly different. Also, do not be fooled by sprinkler boxes!) They can be found in just about every city. To open a bridging head: if it is locked (and you're feeling destructive), put a hammer or crowbar (the same one you used on the manhole) in the slot above the top hinge of the right door. Pull hard, and the door will rip off. Very effective! If it isn't locked (as usual), take a 7/8 inch hex socket and with it, turn the bolt about 1/8 of a turn to the right (you should hear a spring release inside). Holding the bolt, turn the handle all the way to the left and pull out. To Check for a test-set (which are often left by Bell employees), go inside - First check for a test-set (which are often left by Bell employees). There should be a panel of terminals and wires. Push the panel back about an inch or so, and rotate the top latch (round with a flat section) downward. Release the panel and it will fall all the way forward. There is usually a large amount of wire and extra terminals. The test-sets are often hidden here, so don't overlook it (Manuals, as well, are sometimes placed in the head). On the right door is a metal box of alligator clips. Take a few (Compliments of Bell.). On each door is a useful little round metal device. (Says 'insert gently' or' clamp gently - do not overtighten' etc..) On the front of the disc, you should find two terminals. These are for your test set. (If you dont have one, dont despair -I'll show you ways to make basic test sets later in this article). Hook the ring (-) wire to the 'r' terminal; and the tip (+) wire to the other. (By the way, an easy way to determine the correct polarity is with a 1.5v LED. Tap it to the term. pair, if it doesnt light, switch the poles until it does. When it lights,find the longer of the two LED poles: This one will be on the tip wire (+). Behind the disc is a coiled up cord. This should have two alligator clips on it.. Its very useful, because you dont have to keep connecting and disconnecting the fone (test set) itself, and the clips work nicely. On the terminal board, there should be about 10 screw terminals per side. Follow the wires, and you can see which cable pairs are active. Hook the clips to the terminal pair, and you're set! Dial out if you want, or just listen (If someone's on theline). Later, I'll show you a way to set up a true 'tap' that will let the person dial out on his line and receive calls as normal, and you can listen in the whole time. More about this later... On major prefix-area bridging heads, you can see 'local loops' ,which are two cable pairs (cable pair = ring+tip, a fone line) that are directly connected to each other on the terminal board. These 'cheap loops' as they are called, do not work nearLy as well as the existing ones set up in the switching hardware at the exchange office. (Try scanning your prefixes' 00xx to 99xx #'s.) The tone sides will announce themselves with the 1008 hz loop tone, and the hang side will give no response. The first person should dial the 'hang' side, and the other person dial the tone side, and the tone should stop if you have got the right loop.) If you want to find the number of the line that you're on, you can either try to decipher the 'bridging log' (or whatever), which is on the left door. If that doesnt work, you can use the follwing: --------------------------- ANI # (Automatic Number ID) --------------------------- This is a Telco test number that reports to you the number that youre calling from (It's the same, choppy 'Bell bitch' voice that you get when you reach a disconnected #) For the 213 NPA - Dial 1223 408 NPA - Dial 760 914 NPA - Dial 990 These are extremely useful when messing with any kind of line terminals, house boxes, etc. Now that we have bridging heads wired, we can go on... (don't forget to close and latch the box after all... Wouldnt want GE and Telco people mad, now, would we?) ------------------------------------- "CANS" - Telephone Distribution Boxes ------------------------------------- Basically, two types: 1> Large, rectangular silver box at the end of each street. 2> Black, round, or rectangular thing at every telephone pole. Type 1 - This is the case that takes the underground cable from the bridge and runs it to the telephone pole cable (The lowest, largest one on the telephone pole.) The box is always on the pole nearest the briging head, where the line comes up. Look for the 'Call before you Dig - Underground cable' stickers.. The case box is hinged, so if you want to climb the pole, you can open it with no problems. These usually have 2 rows of terminal sets. You could try to impersonate a Telco technician and report the number as 'new active' (giving a fake name and fake report, etc.) I dont recommend this, and it probably won't (almost positively won't) work, but this is basically what Telco linemen do). Type 2 - This is the splitter box for the group of houses around the pole (Usually 4 or 5 houses). Use it like I mentioned before. The terminals (8 or so) will be in 2 horizontal rows of sets. The extra wires that are just 'hanging there' are provisions for extra lines to residences (1 extra line per house, thats why the insane charge for line #3!) If its the box for your house also, have fun and swap lines with your neighbor! 'Piggyback' them and wreak havoc on the neighborhood (It's eavesdropping time...) Again, I don't recommend this, and its difficult to do it correctly. Moving right along... ------------------------------ APARTMENT / BUSINESS MULTILINE DISTRIBUTION BOXES ------------------------------ Found outside the buliding (most often on the right side, but not always... Just follow the wire from the telephone pole) or in the basement. It has a terminal for all the lines in the building. Use it just like any other termination box as before. Usually says 'Bell system' or similar. Has up to 20 terminals on it (usually.) the middle ones are grounds (forget these). The wires come from the cable to one row (usually the left one), with the other row of terminals for the other row of terminals for the building fone wire pairs. The ring (-) wire is usually the top terminal if the set in the row (1 of 10 or more), and the tip is in the clamp/screw below it. This can be reversed, but the cable pair is always terminated one-on-top-of-each- other, not on the one next to it. (I'm not sure why the other one is there, probably as aprovision for extra lines) Don't use it though, it is usually to close to the other terminals, and in...
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