Asterisk not advertizing rfc2833 when receiving SIP call


I have people call me using my SIP-URI. In one instance I have a conference bridge call me and if I’m the right person picking up the phone it expects me to press “1”.

Now despite having the configuration in sip.conf set to rfc2833 I am not able to get the touch tone through.

Running wireshark and looking at the SDP packets we think we know why but we’re not sure at this point if this is an asterisk bug or a configuration issue.

  • The conference bridge sends an INVITE without SDP.
  • My asterisk sends OK with SDP. This SDP is missing telephone-event/8000. Hence the other side is assuming I’m not signaling in rfc2833.
  • Then I press “1”. My asterisk indeed sends rfc2833 however the other side ignores it as I have not advertized in in my SDP.

I hope I’m making sense here. Anyone experienced this issue?