What is DTMF type?
What is DTMF type?
Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers.
What is RFC2833 DTMF?
RFC 2833 (RTP Payloads for DTMF Digits, Telephony Tones, and Telephony Signals) specifies an RTP payload format for carrying dual-tone multi frequency (DTMF) digits, and other line and trunk signals. RFC 2833 specifies a packet format for DTMF digits, line events, and trunk events.
What is the default payload type for a DTMF event?
RTP Event (RFC 2833) uses dynamic payload type ranging from 96 to 127 (I think default is 96). It’s opposed to some other codecs which use static payload type like G.711Mu (payload 0) and G.711A (payload 8). Moreover both the end points during SDP negotiation can use different payload type for DTMF.
What is DTMF out of band transport?
DTMF Out-of-Band Transport Method When using the Out-of-Band transport method, the DTMFs and the voice are transmitted in two different streams where the voice is sent over RTP, but DTMF is sent either in RTP or SIP depending on the chosen transport method (Out-of-Band using RTP or Out-of-Band using SIP.
What is the default payload type under dial-peer?
For example if UAC sends 96 payload type in SDP offer and UAS sends 101 in SDP answer, both UAC/UAS must entertain the payload type of remote end for sending purpose. So this means that UAC will send DTMF in payload 101 whereas UAS will send in 96. AFAIK default payload type can be set to any other value under dial-peer.
What is the difference between UAC 96 and UAS 101 payload type?
For example if UAC sends 96 payload type in SDP offer and UAS sends 101 in SDP answer, both UAC/UAS must entertain the payload type of remote end for sending purpose. So this means that UAC will send DTMF in payload 101 whereas UAS will send in 96.
