SIMPLE (instant messaging protocol)

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In computing, SIMPLE (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). Like XMPP, and in contrast to the vast majority of IM and presence protocols used by software deployed today, SIMPLE is an open standard. Both are IETF standards or proposed standards. Despite its name, SIMPLE is defined by about 30 documents or more than 1000 pages (7 times more than HTTP 1.1, 15 times more than SMTP and IRC). Some parts have been standardized, e.g. RFC 3428. Other parts, in particular IM sessions, are still under discussion. However, several implementations are already available, including the Microsoft Windows Messenger.

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.

See also

• SIP Communicator
• Microsoft Office Communicator

External links

• SIMPLE Working Group: Drafts Status Pages
• Rich Presence - A New User Communications Experience Technology White Paper