SIPDtmfMode() — Changes the DTMF method for a SIP call
SIPDtmfMode(method)
method
Changes the DTMF method for a SIP call. The method can be either inband, info, or rfc2833.
inband
info
rfc2833
exten => 123,1,SIPDtmfMode(rfc2833) exten => 123,2,Dial(SIP/123)
Appendix A, VoIP Channels