The Cisco Session Initiation Protocol (SIP) Calls MIB
module is designed to provide protocol-specific
information on SIP calls which are currently active.
SIP is an application-layer signalling protocol for
creating, modifying and terminating multimedia
sessions with one or more participants. SIP is defined
in RFC 3261 (June 2002).
The endpoints in a SIP communication are called user
agents. A user agent is an application which contains
both a User Agent Client (UAC) and a User Agent Server
(UAS). A UAC is an application that initiates a SIP
request. A UAS is an application that contacts the
user when a SIP request is received and that returns
a response on behalf of the user. This MIB module
provides information on SIP calls and the user agents
initiating these calls. Also, it provides a way to
manage media forking of SIP calls.