68 lines
4.6 KiB
Plaintext
68 lines
4.6 KiB
Plaintext
Other Fone Information
|
|
======================
|
|
|
|
Voltages & Technical Stuff
|
|
--------------------------
|
|
When your telephone is ON-HOOK, there is 48 volts of DC across the tip
|
|
and the ring. When the handset of a fone is lifted a few switches close
|
|
which cause a loop to become connected between you and the fone company, or
|
|
OFF-HOOK. This is also known as the local loop. Once this happens, the DC
|
|
current is able to flow through your fone with less resistance. This causes
|
|
a relay to energize which causes other CO equipment to realize that you
|
|
want service. Eventually, you will end up with a dial tone. This also
|
|
causes the 48 VDC to drop down to around 12 VDC. The resistance of the loop
|
|
also drops below the 2500 ohm level; FCC licensed telephone equipment must
|
|
have an OFF-HOOK impedance of 600 ohms.
|
|
When your fone rings, the telco sends 90 volts of pulsing AC down the
|
|
line at around 15-60 Hz, usually 20 Hz. In most cases, this causes a metal
|
|
armature to be attracted alternately between two electromagnets; thus, the
|
|
armature often ends up striking two bells of some sort, the ring you often
|
|
hear when non-electronic fones receive a call. Today, these mechanical
|
|
ringers can be replaced with more modern electronic bells and other
|
|
annoying signaling devices, which also explains why deaf people can have
|
|
lights and other equipment attached to their fones instead of ringers.
|
|
When you dial on a fone, there are two common types of dialing, pulse
|
|
and DTMF. If you are like me, you probably don't like either and thought
|
|
about using MF or blue box tones. Dialing rotary breaks and makes
|
|
connections in the fone loop, and the telco uses this to signal to their
|
|
equipment that you are placing a call. Since it is one fone that is
|
|
disconnecting and reconnecting the fone line, if someone else picks up
|
|
another fone on the same extension, both cannot make pulse fone calls until
|
|
one hangs up. DTMF, on the other hand, is a more modern piece of equipment
|
|
and relies on tones generated by a keypad, which can be characterized by a
|
|
0,1,2,3,4,5,6,7,8,9/A,B,C,D keypad. Most fones don't have an A,B,C,D
|
|
keypad, for these frequencies are used by the telco for test and other
|
|
purposes.
|
|
|
|
|
|
Scanning Phun Fone Stuff
|
|
------------------------
|
|
Scanning is the act of either randomly or sequentially dialing fone
|
|
numbers in a certain exchange when you are looking for several different
|
|
things. These things could be carriers, extenders, ANI, "bug tracers,"
|
|
loops, as well as many other interesting "goodies" the fone company uses
|
|
for test purposes.
|
|
When scanning for carriers, your local BBS probably has some scanning
|
|
programs, as these became popular after the movie WARGAMES, but what these
|
|
do are to call every fone in an exchange, or a specified range of fone
|
|
numbers in certain exchanges to look for possible carriers and other
|
|
interesting computer equipment. So, if your computer finds a carrier, or
|
|
what seems like a carrier, it will either print it out or save it in some
|
|
file for later reference. With these carriers one finds, one can either
|
|
call them and find out what each is or, if one of them is interesting, one
|
|
can hack or attempt to break into some interesting systems available, not
|
|
to the general public, of course.
|
|
Scanning telephone "goodies" requires time and patience. These goodies
|
|
usually cannot be traced by most unmodified modems, as the frequencies and
|
|
voice transmissions cannot be differentiated from other disturbances, such
|
|
as the annoying operator saying, "We're sorry... blah blah..". Anyway, to
|
|
scan these, you usually get a regular carrier scanner and, with the modem
|
|
speaker on, sit by your wonderful computer and listen in on the scanning
|
|
for any interesting tones, voices, or silences, which could be telco fone
|
|
phun numbers, for us of course! Then write these down, and spread them
|
|
around, use, abuze, etc. if you dare. Anyway, most telefone goodies are
|
|
located in the 99xx suffixes of any fone exchange. If you found everything
|
|
you think in the exchanges you have scanned, try the 0xxx and 1xxx suffixes
|
|
in that order. You might even find loops, ANI, and other phun things if you
|
|
mess around enough.
|