How does iChat start a conversation?

I want to know which protocol does iChat use to start a conversat开发者_JAVA百科ion with other client in LAN ?

is it SIP? or SIP + XMPP? start a session with SIP and exchange message with XMPP? thanks a lot!

It uses Bonjour, XMPP but using multicast DNS for presence, and peer-to-peer connections instead of a server. The protocol was designed by Apple and then openly documented by the XMPP Standards Foundation as XEP-0174: Serverless Messaging.

So, I understand how does ichat work now. DSN-SD + XEP-0174.
unfortunately there isn't any java library for XEP-0174, but the connection is based on socket.
thanks for everyone's attention.