I would like to say that I am fairly new to Asterisk 1.4 but I have been getting around so far. I do have 1 issue which is when I try to call my cellphone to listen to my voice mail, the cellphone carrier doesn’t recognize when I hit * on the phone to enter the password. I have been researching DTMF and I have tried changing
dtmfmode=inband
dtmfmode=auto
dtmfmode=rfc2833 and even
dtmfmode=route. And nothing works. Is there a feature to turn on dtmf or am I completely looking in the wrong direction? Any help would greatly be appreciated. Thank you. 
Two things to consider, what is sending the DTMF (aka your phone) and how it is getting there (IAX to a VoIP-ISP, Zaptel? etc).
We had problems with an our Cisco 2600 router which served as the VoIP to PSTN gateway. Unless Asterisk and our Cisco 7960 desk phones were configured in a very specific way, DTMF didn’t work at all.
[quote=“ShakataGaNai”]Two things to consider, what is sending the DTMF (aka your phone) and how it is getting there (IAX to a VoIP-ISP, Zaptel? etc).
We had problems with an our Cisco 2600 router which served as the VoIP to PSTN gateway. Unless Asterisk and our Cisco 7960 desk phones were configured in a very specific way, DTMF didn’t work at all.[/quote]
I just have a regular house phone connected to my RT31P2 Linksys adapter. In the linksys it have the option to change the DTMF mode but when I change it to what corresponds to what is in my SIP.CONF file, it still doesn’t work. Any other suggestions?