amb@cs.columbia.edu (Andrew Boardman) (08/16/89)
In article <telecom-v09i0297m05@vector.dallas.tx.us> kent wrote: >The phone on my desk says Ameritech on it. The designers knew that >people expect to hear tones when they dial a push button phone, but >they are not using tones to communicate with the PBX, so they have two >single tones which alternate with each keystroke. ROLM PBXen (this one at least) have one uniform tone that is sounded when any key is pressed. Real DTMF of fixed length and fixed intervals is sent out the other end, though, even on a call to another phone on the PBX. (If one dials very fast, it can take quite a while for the PBX to finish pulsing out the tones. It is possible to tie up a ROLM extension by calling it and, when the other party ansers, dialing very very fast, such that the PBX has to spend quite a while pulsing out the appropriate tones. Even after one hangs up, the other party *can't* until the PBX is done playing it's measured frequencies. (Unplugging the phone or hanging up won't work; when the phone is plugged back in, the call-in-progress light will still be lit, and when the phone is taken off-"hook", you will still hear that beep-beep-beep.)) Andrew Boardman amb@cs.columbia.edu ROLM is a four letter (and if you really have to, ab4@cunixc on bitnet) word.