5/28/2023 0 Comments Dtmf online![]() ![]() Female voice is known to once in a while trigger the recognition of a DTMF tone. ![]() When sent as audio, only uncompressed codecs such as G.711 (alaw and ulaw) can carry DTMF reliably. Two methods are available, either as audio tones transmitted encoded into RTP packets just like voice or as named telephony events in specially marked RTP packets according to RFC 2833 (obsolete) or RFC 4733. Inband means that DTMF is transmitted in the same network connection as the audio of the phone conversation. A typical application where you’d want control of the duration of the keypress is controlling an electric door opener. This is a tricky issue: You cannot expect to have control over the duration of DTMF signals when using SIP INFO in general, or RFC2833 before Asterisk 1.4.0: For example, cell phone carriers transmit keys pressed on your GSM phone to fixed length signals regardless of how long you pressed that key. ![]()
0 Comments
Leave a Reply. |