Can't Send Tones

I have PBX in a Flash set up and working well on an SIP trunk outbound. I’ve begun having difficulties sending DTMF tones. So when I reach an auto attendant, and I enter one or more digits, nothing happens. This behavior started around the time I set up a new Aastra 57i phone. Do you think that might have changed a setting? I can still dial the phone OK to reach outside parties, but can’t get auto-attendants on the other end to respond at all. The behavior occurs with my Aastra phone and also with XLite soft phone too.

Thanks for any thoughts you may have!

Jim S.

Try changing the DTMF setting in the extension setup to inband. Make sure the phone is using ulaw or alaw when you do that.

Yeah, I had this barrel of fun too.
I had to change the DTMF settings in the trunk.

Try adding either dtmfmode=rfc2833 or dtmfmode=auto in the PEER section of the trunk settings
Can’t remember if you need to do amportal restart in the CLI for it to take effect though. Try that if it doesn’t work at first.

As John metioned, also check to see that the extensions have DTMF rfc2833 (should be in there by default)

I will try both. The funny thing is everything was working great before I installed that Aastra phone. I suspect the install script did something to my settings…


Jim S.

I changed the dtmfmode in the outbound trunk dtmfmode=inband, and voila, I can now transmit tones. Thanks much Magpye and JMullinix.