[Asterisk-Users] Brief silence followed by DTMF tone on T1 line

[Kevin P. Fleming]

Hunt, Bill wrote:
> Every once in a while calls get interrupted with a brief silence
> followed by a DTMF tone on our T1 lines. We are using a TE411P card. It
> does not happen on SIP connections, just the T1. Has anyone experienced
> this or know a possible cause?

Yes, it's called talk-off. It happens when the VPM on your TE411P
mis-detects a DTMF tone during normal conversation.

There is a DTMF threshold setting that can be adjusted in the TE411P
driver to combat this problem; contact Digium Technical Support and they
can help you adjust it (which can be done without interrupting the
operation of your system).