Cisco User Agent Session Initiation Protocol (SIP) MIB module. SIP is an application-layer signalling protocol for creating, modifying and terminating multimedia sessions with one or more participants. These sessions include Internet multimedia conferences and Internet telephone calls. SIP is defined in RFC 2543 (March 1999).
This MIB is defined for the management of SIP User Agents (UAs). 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. The response accepts, rejects, or redirects the request.
A SIP transaction occurs between a client and a server and comprises all messages from the first request sent from the client to the server up to a final (non-1xx) response sent from the server to the client.