![]() ![]() This field indicates an ability to use NOTIFY for DTMF tones and the duration of each tone in milliseconds. NOTIFY-based out-of-band DTMF relay is negotiated by including a Call-Info field in the SIP INVITE and response messages. When a gateway receives an INFO message containing DTMF relay information, it sends the corresponding tone. The SIP INFO method sends DTMF digits in INFO messages. One uses SIP INFO methods, and the other uses SIP NOTIFY methods. Cisco has two out-of-band procedures for DTMF relay.
0 Comments
Leave a Reply. |