User's Manual 28 Document #: LTRT-89730
Mediant 3000
Figure 1-3: Mediant 3000/TP-8410 Functional Block Diagram
1.1.2 SIP Overview
Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol used on
the E-SBC and gateway for creating, modifying, and terminating sessions with one or more
participants. These sessions can include Internet telephone calls, media announcements,
and conferences.
SIP invitations are used to create sessions and carry session descriptions that enable
participants to agree on a set of compatible media types. SIP uses elements called Proxy
servers to help route requests to the user's current location, authenticate and authorize
users for services, implement provider call-routing policies and provide features to users.