Session Initiation Protocol
OverviewHistoryProtocol operationNetwork elementsSIP messagesTransactionsInstant messaging and presenceConformance testing
The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, modifying, and terminating communication sessions that involve multimedia elements such as voice, video, and messaging. It operates at the application layer of the Internet protocol suite and is widely used in Internet telephony, private IP-based telephone systems, and mobile communication over LTE networks t