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.