This introduction is meant for beginners. This beginners' made easy tutorial is to give a brief introduction to SDP before one ventures into the long RFC documents. However, if you are a veteran please go through this short tutorial and suggest modifications.
What is SDP?
SDP is the short form of Session Description Protocol. It is used to describe multimedia sessions in a format understood by the participants over a network. Depending on this description a party decides whether to join a conference or when or how to join a conference.
The owner of a conference advertises it over the network by sending multicast messages which contain description of the session e.g. the name of the owner, the name of the session, the coding, the timing etc. Depending on these information the recipients of the advertisement take a decision about participation in the session. We will go through the basic structure next.
SDP is generally contained in the body part of Session Initiation Protocol popularly called SIP. If you want to know about SIP please go through the Introduction to SIP a Made Easy Tutorial.
You can go through this presentation as an Introduction to Session Description Protocol(SDP) (Opens .pdf in new window) to get started.