need help on 3cx question

[davidlee]

is SIP protocol itself includes Codecs(audio) description ? im quite confuse this.. is suppose SDP is handle audio codecs description right instead of SIP ? appreciate anyone can help on this ?

 

[NickD_3CX]

VoIP Generally consists of 2 Protocols, SIP and RTP. SDP is a part of the SIP.

You can even see this if you capture a call in e.g. Wireshark, and you will see that the SIP information is in the Message Header, and the SDP information is in the Message Body.

But yes, the SDP is where the Media Negotiation happens