CONNECT (logon_id) CHAT_INITIATED( lobby_id, participants ) CHAT_JOINED( lobby_id, logon_id ) POST_CHAT(sender_id, chat_id, message) (SEND_MESG) CHAT_POSTED( chat_id, sender_id, message) (RECEIVE_MESG) REQUEST_CHAT(initiator_id, participant_list) (NEW_CHAT) CHAT_INITIATED( chat_id, participants ) CHAT_REQUESTED( chat_id, initiator_id, participants ) JOIN_CHAT( chat_id, logon_id ) CHAT_JOINED( chat_id, logon_id ) LEAVE_CHAT( chat_id, logon_id ) CHAT_LEFT( chat_id, logon_id ) DISCONNECT (logon_id) CHAT_LEFT( chat_id, logon_id )