SAP Overview

Session announcements are handled by two protocols: the Session Announcement Protocol (SAP) and the Session Description Protocol (SDP). These two protocols display multicast session names and correlate the names with multicast traffic. Only SAP has configuration parameters that users can change.

SDP is a session directory protocol that is used for multimedia sessions. It helps advertise multimedia conference sessions and communicates setup information to participants who want to join the session. SDP simply formats the session description; it does not incorporate a transport protocol. A client commonly uses SDP to announce a conference session by periodically multicasting an announcement packet to a well-known multicast address and port using SAP.

SAP is a session directory announcement protocol that SDP uses as its transport protocol.

For information about supported standards for SAP and SDP, see Junos OS Multicast Standards.