Echo Canceler

Hi, the general concept of an echo canceler is to preserve the original signal (only) and suppress noise that exists from repeaters, amplifiers, wiring, etc. A significant component of this "noise" is phase-shifted from the original signal which can appear as an echo of the original wave form. In the bad old days of analog voice comm, a bad echo canceler might cause the line quality to be like a bad overseas cable, with actual audible "echo". The DTMF signals are not as "timing" dependent as the voice or data components and so probably would be unlikely to be affected. It depends on exactly what is "bad" about the echo canceler, though! hope this helps your understanding. -Will

If the echo cancellation circuits are bad, you won't have communications with the distant end. Telecom switches use echo cancellation on trunks. If the DTMF signals aren't being recognized it's either your phone is hosed (Make sure it's not set for dial pulse) or the line card is bad.

Try a different phone and if your problem is the phone, the new phone will work.

If you've got a line connection that isolates your phone from the house wiring, try that. You could have a grounding problem.

This question was closed by the author