An SDP message consists of several lines of text in the format = . A typical file or message contains three main sections:
: The core part where the actual parameters are defined, including: Media Type : Whether it is audio, video, or text ( m= ). Network Address : Where to send the media ( c= ). Port Numbers : Which port is listening for the stream. SDP.mp4
: Specifies when the session is active ( t= ). An SDP message consists of several lines of
: Which compression formats (e.g., H.264, VP8) are supported ( a=rtpmap ). How it Works (Offer/Answer Model) Systems use an Offer/Answer model to connect: The Secret Protocol Making Video Calls Work | SDP in WebRTC Port Numbers : Which port is listening for the stream
The is a text-based format used by communication systems (like SIP or WebRTC ) to agree on technical details before a call begins. It doesn't carry the actual video or audio; instead, it acts as a "blueprint" or "technical handshake". Key Components of an SDP Message