SIMPLE (instant messaging protocol)

SIMPLE, the Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions, is an instant messaging (IM) and presence protocol suite based on Session Initiation Protocol (SIP) managed by the Internet Engineering Task Force. == Purpose == SIMPLE applies SIP to the problems of: registering for presence information and receiving notifications when such events occur, for example when a user logs in or comes back from lunch; sending short messages, analogous to SMS or two-way paging; managing a session of real-time messages between two or more participants.

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