JXTA NOTE:Network Organization

 
The JXTA network is an Ad-Hoc, multi-hop, and adaptive network composed of connected peers. Connections in the network may be transient and, as a result, message routing between peers is non-deterministic. Peers may join or leave the network at any time; which results in ever changing routing information.
The only common aspect that various JXTA applications share is that they communicate using JXTA protocols. The organization of the network is not mandated by the JXTA framework, but in practice four kinds of peers are typically used:
minimal edge peer
A minimal edge peer can send and receive messages, but does not cache advertisements or route messages for other peers. Peers on devices with limited resources (e.g., a PDA or cell phone) would likely be minimal edge peers.
null-featured edge peer
A full-featured peer can send and receive messages and will typically cache advertisements. A simple peer replies to discovery requests with information found in its cached advertisements, but it does not forward any discovery requests. In any JXTA deployment most peers are likely to be edge peers.
Rendezvous peer
A rendezvous peer is an infrastructure peer, it aids other peers with message propagation, discovery of advertisements and routes, and most importantly it maintains a topology map of of other infrastructure peers, which then used for controlled propagation, and maintenance of the distributed hash table. Each peer group maintains its own set of rendezvous peers and may have as many rendezvous peers as needed. Edge peers send search and discovery requests to their rendezvous peer which in turn may forward requests it cannot answer to other known rendezvous peers using the topology mapped distributed hash table.
Relay peer3
A relay peer s an infrastructure peer, it aids non addressable (firewalled/NAT'd) peers with message relaying. A peer may request an in memory message box from a relay peer to facilitate message relaying whenever needed.