I am using asterisk 14. from ringing RTP start sending .I am concerning about bandwidth. So it start consumes bandwidth from ringing. Is there any way to send RTP only once user picked up phone and start conversion ? Regards.
This depends on dialplan configuration and what you have dialed. Asterisk can be forced to provide ringing as inband media or out of band, it will also forward ringing as media if it is received as media. If you provide the console output it should be possible to see what is happening but the answer may be that you can’t change it.
Before the conversion start really,Asterisk only created connect for the two ends via SIP, so that they could send audio or video stream through RTP when they really start to conversion.
Asterisk will use early media if it receives it and knows where to send it.
Whilst there is a common mistake of starting dialplans with Answer, which will ensure that ringback is sent as normal media, if the downtream system sends ringback as early media, and Asterisk has received SDP, it is likely to forward it to the caller.
If you have the choice of late offer SDP, in the SIP client, and don’t answer, Asterisk will have nowhere to send any early media. (If the downstream UAC only uses early media for ringback, this means the caller will not hear anything. In any case, most devices do not use late offer SDP.)