Cable Pair Indication M P

| e iNFERNO `95. e | 
P D D P 
+ -------------------------------------------------------------------- + 

Its amusing to read about the number of myths that Cable Pair Indication 
has drummed up in it's existance. Most people KNOW the CPI number, yet 
don't know that it is CPI and don't know what it does. People have put 
fowards all sorts of suggestions ranging from a coin pulse generator to 
ROUs (Remote Observation Units). None of this is evan near the truth 
and the fact is that to the casual phreak it has little indirect use. 

The CPI `number' is 176, coupled in with the other B.T SALT test numbers 
for Systems X and Y and the other varying test lines for more primitive 
systems. It, as far as I know, works everywhere in England (I could be 
wrong) and is bascially an automatic Osciallator. 

B.T use Osciallators to identify line cable pairs in CAB or PILLER boxes 
(The green B.T things you find at road sides.). The basic idea is that 
they apply an oscilating tone to the line from the phone termination 
point in the subscribers house and then go to the nearest CAB box, open 
it and use a standard BT amplifier that they can wave around the box a bit 
making themselves look important and it will start to beep when near to 
the subscribers line. This is because it picks up the tone that the 
oscillator is giving out. 

Now, B.T have gone a bit hi-tech and instead of wasting man-power, they 
have set up this `176' number that will eliminate the physical use of the 
oscillator because it's all done for them... 
The engineer dials `176 + Full standard code' and, if lines are free he 
will here a series of beeps to identify connection, then he can zip round 
to the CAB box, wave his amplifier around a bit and bing - the line has 
been identified. 

This could be useful to tap someones line due to the fact you don't have 
to go anywhere near their house, just their area (it can only be used in 
local area). A side affect it does have it that it engages the subscribers 
line you enter so no calls may be made to that house, although calls may 
be made out without the subscriber ever knowing.. which could be used with 
a little imagination to conjour up some pretty mean deeds.. 
 .. MED 

Back to document index 

6Mb free web space. Click here. 6Mb free web space. Click here.