Using RINGBACK in the NPA (502) by Predat0r Ringback is used by the phone company to test a line to make sure it is working. Anyone can do it from their own home phone. The format is as follows. NXX-XXXX. Where NXX is the ringback prefix, and XXXX is the last four digits of the calling station. (your phone number) Some exceptions to this are non Bell-Systems exchanges like (GTE, et al.) The following are ringback prefixs listed in decreasing order of use. 958 - 959 - 750 - 350 - 270 - and 820 Examples: NPA-NXX-XXXX / 502-958-1234 You do not need the area code, just use the format NXX-XXXX in example NXX = 958 ringback prefix and the XXXX = the calling stations last four digits. If the correct ringback code is dialed an ESS "dialtone" will be heard. At this point a DTMF test is available if the calling line has touch tone service. Press 1234567890 in a 15 second period and a double burst of a single tone will interrupt the "dialtone" to indicate proper functioning. If a wrong digit is hit the test will reset in 15 seconds with a single, single tone burst. To activate ringback: Flash the hookswitch like using call waiting and the dialtone will be replaced with a single tone. Go on hook and the station will ring. Pick up the phone and the single tone returns. Going on hook again or pressing a key will terminate the procedure, but flashing again and hanging up will allow the procedure to be repeated. This text file is for informational purposes only. But everything works, and Ma-Bell really can't do anything to you for using ringback so have fun.