File: A HISTORY OF BRITISH PHREAKING

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		 $   The History Of British Phreaking  $
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		 $     The second in a series of       $
		 $     THE HISTORY OF.....philes       $
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		 $	 Written and Uploaded by:      $
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		 $$$$$$$$$$$$-=>Lex Luthor<=-$$$$$$$$$$$
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		 $	   The Legion Of Doom!	       $
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With thanks to Peter McIvers for the list of frequencies mentioned later in
this phile.

NOTE: the British Post Office, is the U.S. equivelent of Ma Bell.

   In Britain, phreaking goes back to the early fifties, when the technique of 
'Toll A drop back' was discovered. Toll A was an exchange near St. Pauls which 
routed calls between London and nearby non-London exchanges. The trick was to 
dial an unallocated number, and then depress the reciever-rest for 1/2 second. 
This flashing initiated the 'clear forward' signal, leaving the caller with an 
open line into the Toll A exchange. He could thjen dial 018, which forwarded 
him to the trunk exchange- at that time, the first long distance exchange in 
Britain- and foll ow it with the code for the distant exchange to which he 
would be connect ed at no extra charge.

   The signals needed to control the UK network today were published in the
"Institution of Post Office Engineers Journal" and reprinted in the Sunday 
Times (15 Oct. 1972).

   The signalling system they use: signalling system No. 3 uses pairs of
frequencies selected from 6 tones separated by 120Hz. With that info, the
phreaks made "Bleepers" or as they are called here in the U.S. "Blue Box", but
they do utilize different MF tones then the U.S., thus, your U.S. blue box that
you smuggled into the UK will not work, unless you change the frequencies.

   In the  early seventies, a simpler system based on different numbers of   
pulses with the same frequency (2280Hz) was used. For more info on that, try to
get ahold of: Atkinson's "Telephony and Systems Technology".

   The following are timing and the frequencies for boxing in the UK and other 
foreign countries. Special thanks to Peter McIvers for the phollowing inpho:

British "bleeper" boxes have the vaery same layout as U.S. blue boxes. The 
frequencies are different, though.  They use two sets of frequencies, forward 
and backward.  Forward signals are sent out by the bleeper box; the backward 
signals may be ignored (it's sort of like using full duplex).  The frequencies 
are as follows:

U.S.:
US:	     700    900    1100   1300	 1500	1700
Forward:    1380   1500    1620   1740	 1860	1980 Hz
Backward:   1140   1020    900	   780	  660	 540 Hz

for example, change the 900 Hz potentiometers in your box to 1500 Hz. All 
numbers 1-0 (10) are in the same order as in an American box. The ones after 
this are thier codes for operator 11, operator 12, spare 13, spare 14, and 15. 
One of these is KP, one (probably 15) is Star; it won't be too hard to figure 
out. The signals should carry -11.5dBm +/- 1dB onto the line; the frequencies 
should be within +/- 4Hz (as is the British equipment). Also, the 1VF system is
still in operation in parts of the U.K. This would encode all signals 1 to 16 as binary numbers; for instance, a five is 0101.	There are six intervals per 
digit, each 50ms long r a total of 300ms.  First is a start pulse of 2280 for 
50ms.  Then, using the example of five (0101), there is a 50ms pause, a 50ms 
pulse of 2280, a 50ms pause, and a 50ms pulse of 2280.	Finally, there is a 
50ms pause that signals the end of the digit.  The frequency tolerance on the 
2280 Hz is +/- 0.3%; it is sent at -6 +/- 1dBm.  An idle line is signaled by 
the presence of a 3825Hz tone for more than 650ms. This must be within 4Hz.

France uses the same box codes as the US, with an additional 1900Hz 
acknowledgement signal, at -8.7 +/- 1dBm per frequency.

Spain uses a 2 out of 5 mf code (same frequencies as US), with a 1700 Hz 
acknowledge signal.

Other places using the 1VF system are:
Australia, 2280Hz +/-6Hz, 35ms/digit at -6dB.
Germany, France: same as Australia; also, some 1VF systems in the UK.
Switzerland: same as Australia, only it uses 3000Hz, not 2280.
Sweeden: same as above, but at 2400Hz.
Spain: some parts use 1VF with 2500Hz.

There is one other major system: the 2VF system.  In this system, each digit is
35ms long.  The number is encoded in binary as with the 1VF system.  Using the 
example of five (0101), here's how the American 2VF system was sent:
2400 pulse, pause, 2040 pulse, pause, 2400 pulse, pause, 2040 pulse, pause. The
digits and pauses are all 35ms long, for a total of 280ms per digit. Other 
countries are still using a similar high/low pair with the same timings.  Some 
parts of Italy use the 1VF system with 2040Hz; some use the 2VF system with 
2040 and 2400 (same as original US) Hz. The Netherlands uses a 2VF system with 
2400 and 2500 Hz pulses. With the 2VF system, all frequencies should be within
2Hz.

Also, here are some specs for American phone equipment:
Dial Tone: 350+440Hz, -17.5 to -14.5 dBm/tone.
Off-Hook (ROH): 1400+2060+2450+2600(!) on/off 5 times per second
Busy: 480+620Hz; solow busy: 0.5 +/- 0.05 sec = 1 period
(about twice a second), at -28.5 to -22.5 dBm/tone.

Ring: 440+480 Hz at -23.5 to -20.5 dBm/tone.
A ring is modulated at 20 +/- 3Hz, 2sec on, 4sec off.

Call waiting: 440Hz, on 1 second.

Recorder Connection: 1400Hz, beeps every 15minutes.
Multiparty line ring: sam% frequency and modulation as ring, but 1sec on, 2sec 
off (twice as fast).

  Now, back to British Phreaking:In the early days of British phreaking, the 
Cambridge University Titan Computer was used to record and circulate numbers 
found by the exhaustive dialing of local networks. These number s were used to 
create a chain of links from local exchange to local exchange across the 
country, bypassing the trunk circuits. Because the internal routing codes in 
the UK network are not the same as those dialed by the caller, the phreaks had 
to discover them by 'probe and listen' techniques or more commonly known in the
U.S.--SCANNING. What they did was put in likely signals and listened to find 
out if they succeeded. The results of scanning were circulated to other 
phreaks. Discovering each other took time at first, but evenutally the phreaks 
became organized. The "TAP" of Britain was called "Undercurrents" which enabled
British phreaks to share the info on new numbers, equipment etc.

   To understand what the British british phreaks did, think of the phone
netowrk in three layers of lines: Local, trunk, and international. In the UK, 
Subcriber Trunk Dialing (STD), is the mechanism which takes a call from the 
local lines and (legitimately) elevates it to a trunk or international
level. The UK phreaks figured that a call at trunk level can be routed through 
any number of exchanges, provided that the right routing codes were found and 
used correctly. They also had to discover how to get from local to trunk level 
either without being charged (which they did with a bleeper box) or without 
using (STD). Chaining has already been mentioned but it requires long strings 
of digits and speech gets more and more faint as the chain grows, just like
it does when you stack trunks back and forth accross the U.S. The way the 
security reps snagged the phreaks was to put a simple 'printermeter' or as we 
call it: a pen register on the suspects line, which shows every digit dialed
from the subscribers line.

   The British prefer to get onto the trunks rather than chaining. One way was 
to discover where local calls use the trunks between neighboring exchanges, 
start a call and stay on the trunk instead of returning to the local level on 
reaching the distant switch. This again required exhaustive dialing and made 
more work for Titan; it also revealed 'fiddles', which were inserted by Post 
Office Engineers. What fiddling means is that the engineers rewired the 
exchanges for thier own benefit. The equipment is modified to give access to a 
trunk with out being charged, an operation which is pretty easy in Step by Step
(SXS) electromechanical exchanges, which were installed in Britain even in the 1970s (NOTE: I know of a back door into the Canadian system on a 4A CO., so if 
you are on SXS or a 4A, try scanning 3 digit exchanges, ie: dial 999,998,997 
etc. and listen for the beep-kerchink, if there are no 3 digit codes which 
allow direct access to a tandem in your local exchange and bypasses the AMA so 
you won't be billed, not have to blast 2600 every time you wish to box a call.

  A famous British 'fiddler' revealed in the early 1970s worked by dialing 173.
The caller then added the trunk code of 1 and the subscribers local number. At 
that time, most engineering test services began with 17X, so the engineers 
could hide thier fiddles in the nest of service wires. When security reps 
started searching, the fiddles were concealed by tones signalling: 'number 
unobtainalbe' or 'equipment engaged' which switched off after a delay. The 
necessary relays are small and easily hidden.

 $There was another side to phreaking In the UK in the sixties. Before STD was 
widespread, many 'ordinary' people were driven to occasional phreaking from 
sheer frustration at the inefficient operator controlled trunk system.
This came to a head during a strike about 1961 when operators could not be 
reached. Nothing complicated was needed. Many operators had been in the habit 
of repeating the codes as they dialled the requested numbers so people soon 
learnt the numbers they called frequently. The only 'trick' was to know which 
exchanges could be dialled through to pass on the trunk number. Callers also 
needed a pretty quiet place to do it, since timing relative to clicks was important

 The most famous trial of British phreaks was called the Old Baily trial. Which
started on 3 Oct. 1973. What they phreaks did was to dial a spare number at a 
local call rate but involving a trunk to another exchange Then they send a 
'clear forward' to thier local exchange, indicating to it that the call is 
finished;but the distant exchange doesn't realize because the caller's phone is
still Off the hook. They now have an open line into the distant trunk exchange 
and sends to it a 'seize' signal: '1' which puts him onto its outgoing lines.
Now, if they know the codes, the world is open to them. All other exchanges 
trust his local exchange to handle the billing; they just interpret the tones 
they hear. Mean while, the local exchange collects only for a local call. The
investigators discovered the phreaks holding a conference somewhere in England 
surrounded by various phone equipment and bleeper boxes, also printouts listing
'secret' Post Office codes. (They probably got them from trashing?) The judge 
said: "some take to heroin, some take to telephones" for them phone phreaking
was not a crime but a hobby to be shared with phellow enthusists and discussed 
with the Post Office openly over dinner and by mail. Their approach and 
attitude to the worlds larges computer, the global telephone system, was that 
of scientist s conducting experiments or programmers and engineers testing 
programs and systems. The judge apeared to agree, and even asked them for 
phreaking codes to use from his local exchange!!!

	     $-The End-$

Look for my other phine philes:      The History Of E.S.S.
				     Electronic Toll fraud devices (Boxes)
				     Bell Security Tactics
				     & other typed in philes on many subjects.

And coming soon to a Phreak Board near You: All you ever wanted to know about
any Central Office, from SXS, PANEL to E.S.S. #1.

Later on......$-=>Lex Luthor<=-$
Remote sysop of Plover-net 516-935-2481 and Sysop of: The Legion Of Doom!
	      305-COE-XXXX
If your good, you'll find out the #.

[Courtesy of Sherwood Forest ][ -- (914) 359-1517]

