paul@dual.UUCP (Baker) (10/27/84)
> I thought DTMF meant 'Dual Tone Multi-Frequency'. Contrary to > popular usage, TOUCH-TONE and DTMF are not the same. TOUCH-TONE is > what the keypad on your telephone produces. DTMF is used for sending > call information from one central office to another. > By the way, the tones used for DTMF are not the same as the tones > generated by your telephone pad. I'm afraid the above just isn't true. DTMF is the same as Touch-Tone (tm). Look, for example at the EIA specification RS-470 describing Telephones. It specifically states DTMF and gives frequencies. The signalling method subject to being fooled by "Blue-boxes" is known as MF. The publication which gave out the MF frequencies was apparently hastily removed as soon as the implications were realized. These frequencies are not produced by the DTMF or Touch-Tone (tm) pad in ones telephone and certainly not by a dial phone ! Paul Wilcox-Baker.