5RFC 3921. Extensible Messaging and Presence Protocol (XMPP) : Instant Messaging and Presence http://www. ietf. org/rfc/ rfc3920, txt, 2004
6RFC 3922. Mapping the Extensible Messaging and Prese - nee Protocol (XMPP) to Common Presence and Instant Messaging. http://www.ietf. org/rfc/rfc3922, txt, 2004
7RFC 3923. End - to - End Object Encryption in the Extensible Messaging and Presence Protocol (XMPP). http://www. ietf. org/rfc/rfc3923. txt, 2004
8SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE). http://www. ietf. org/html, charters /simple-charter. html,2007
9Zhang Yun chuan. Standardized Instant Messaging Protocols : Comparative Analysis of SIMPLE and XMPP. Journal of Wuhan University of Science and Technology (Natural Science Edition), 2005,4
10Petrack S . SIMPLE Aims for IM Interoperability . Network World,2004,21(3) : 39