US Patent 7966368 Communicating messages over transient connections in a peer-to-peer network

Systems and methods useful in communicating messages over a peer-to-peer network, optionally over transient connections to participants in a collaborative session (e.g., an “electronic whiteboard” session), are described. Examples include establishing a session for data transfer, wherein participants easily enter and leave the session without losing data or connections between the participants. Participants in a session may gain access to and catch up with data previously transmitted. Various data structures are useful for communicating messages. Such data structures may be used for transmitting message data or identification data to participants.