analyse protocol of a internet chat (java and mobile clients)

Hi there. I'm interested, how this internet chat works: [login to view URL] How can messages be read and transmitted with an external software etc. They provide a java applet on their website, a download version and they provide mobile clients for Android and iOS. I don't want to use it for spamming or something. I am just interested in the protocol. I tried to analyse it myself, but I never got any results. A tool that might help you is Wireshark. Thanks for help Lars-Daniel