JXTA Concepts

Each peer is given a 128-bit unique identifier (UUID). These are not guaranteed to be globally unique.
Advertisements are XML documents that describe the existence of peers, peer groups, pipes, or services.
A peer is an entity that can understand all the required protocols.
Messages are the basic unit of communication. They should operate on asynchronous, unreliable, uni-directional transport. Messages contain an envelope and a body.
A peer group is a virtual entity that speaks the set of peer group protocols. There are no membership requirements. The World Peer Group includes everyone.
Pipes are communication channels for sending and receiving messages. They are unidirectional and asynchronous. Their endpoints can be moved among peers.
- A point-to-point pipe connects exactly two peers, sender and receiver.
- A propagate pipe connects multiple peer endpoints together.