In the earlier sections (Sections 2–16), we have considered the Session Description Protocol (SDP) signaling messages that are used for negotiations of capabilities related to network, transport, session, media, and security attributes. During negotiations, SDP signaling messages are sent back and forth between the endpoints. These endpoints can be humans and/or automat. However, it is critical that the security of these individual SDP signaling messages be provided during negotiations. Each of these Request for Comments (RFCs) related to Sections 2–16 also describes how security needs to be assured for those individual SDP signaling messages. We have described all of the security features described in those RFCs of Sections 2–16 so that the SDP signaling messages described in the subsequent sections create a unified global security picture by virtue of having all of them together in one place. The security parameters for media stream/payload (e.g., audio, video, and/or data [test, graphics, and/or animation]) are negotiated using SDP before the setup of the call. During the actual media transfer between the endpoints, those security algorithms/parameters/features are used as agreed upon before the call setup using SDP.