Phantom Fax Tones

[Raffles666]

Has anyone tried the 'fax tone cutting over a VoIP call' problem with version 3 yet?

In case you haven't heard of it, VoIP calls would suddenly get a fax tone over the top of their voice call.

This was sorted after a bit of investigation - but the answer is a wierd one (clue - it's a bit like phantom DTMF dialling).


Old school Alchemy engineer - trying to keep up with the times

 

[IPGuru]

The problem is OoutOfBand DTMF
The DTMF detection in the IPO was a little aggressive & speach could somtimes be interpreted as a DTMF keypress so the command was sent to the remote site to send a DTMF digit

Turning of OutOfBand DTMF in the voip line will cure the problem (but may cause difficulties with auto attendants etc.)

 

[Raffles666]

We tried this - and this was NOT the case. The DTMF problem was due to hands free dialling.

Imagine two phones very close to each other - both using handsfree dialling at exactly the same time. DTMF tones from phone 1 were being interpreted by the microphone on phone 2 (and vice-versa).

Hence, the mis-dailling. Took me ages to find that one.

You guessed the 'faxtone over voice' solution now?

cheers





Old school Alchemy engineer - trying to keep up with the times