Skip navigation

Monthly Archives: June 2009

We’ve had a recent issue with IAX2 trunks whereby any DTMF tones played locally are not audible at the remote side of the connection…

Interestingly tones were audible on inbound and internal calls, however, this means that IVR’s are completely non-navigable.

The problem turned out to be due to the fact that it appears DTMF traffic was being sent out over a separate UDP port to the rest of the IAX traffic….calls sounded fine, but DTMF traffic was being blocked due to it running on port 4571.  We’ve opened the range 4569-4571 and now all is working fine….