I am working on a project of P2P instant messenger, like ichat, but just for LAN.
I use jmdns library for service discovering, and test with pidgin and log in as a Bonjour user. as so far,the service _presence._tcp.local. is well discovered,
then we know the user's information in LAN like name@host:port, so how to start a conversation with Bonjour client ?
I looked into XMPP, but it do not support P2P, but I can hardly find the library for the extension jingle which supports P2P.
maybe I should use SIP to make a conversation? but the packet format is compatible with Bonjour ? or I have to study the structure of packet exchanged?
Can anyone explain a little about how does ichat work for LAN?
Many thanks for your kind help！
I think you're a little confused.
Bonjour is a mechanism for finding a service. It is not for communicating with a service. Once you have found the name@host:port information, you are finished with Bonjour.
The next step will require you to talk a protocol that the service understands. The token _presence in the service string indicates that this is an XMPP service. You will need to talk XMPP to it. You cannot talk SIP to it. Have you tried opening an XMPP connection to the host and port you have found?
You talk about SIP and Jingle. These are used to set up an audio or video call. If you are writing an instant messaging program, you do not need to do this. XMPP alone is enough.
If you do want to support audio or video, then you will need one of those protocols. Because the service you have found is an XMPP service, you will need to use Jingle. If you don't have a library that can speak Jingle, you will have to write the code yourself. There is nothing in the Bonjour information that identifies a SIP service, so you cannot use SIP - unless you can make a different Bonjour query and find a SIP service.
I infer that you are working in Java. The most popular XMPP library for Java seems to be Smack.