User`s manual

User's Manual 1. Overview
Version 2.2 17 July 2007
The figure below illustrates a typical MediaPack VoIP application.
Figure 1-1: Typical MediaPack BRI VoIP Application
1.3 SIP Overview
SIP (Session Initialization Protocol) is an application-layer control (signaling) protocol used
on the MediaPack 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 Description Protocol (SDP)
messages 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.
SIP also provides a registration function that enables users to upload their current locations
for use by Proxy servers. SIP, on the MediaPack, complies with the IETF (Internet
Engineering Task Force) RFC 3261 (refer to http://www.ietf.org
).