For long time, the internet protocol was the only solution to transport information thru internet network.

But this protocol has limitations and developers need a new protocol to communicate, JXTA is the answer, here is a list of limitation of the internet protocol:

• A connected device can use the same public IP than other local area network device (behind gateway)

• Devices sharing the same public IP cannot accept external connexion on the same TCP/UDP Port
• Packet are transmit point to point (or point to multipoint) using gateway, but no optimization for the packet path

Some problems can be solve using some special services (build over IP), but not compatible between them.
JXTA is the solution, a universal protocol to communicate over internet using peer to peer technology.

JXTA can be implemented in different way; in any case programming with JXTA will give you all this advantage:

• Connected devices had a unique identifier, enabling accessing separately two devices in same local area network, or even two instances on the same device!

• Packets are transmit using peer to peer, enabling packet path optimization and powerful multicast transfer
• Packets can be routed thru a peer that didn't run the same software than the original sender, all JXTA peers are inter-connected
• Packets can pass thru firewall to connect to any device having access to internet
• Developing using JXTASocket it's same as standard Socket, only difference is addressing

In something’s like 2 hours I had convert a complete TCP/IP project to JXTA Technology using JXTA Socket... Most time spend on using JXTA address instead of ip address.

JXTA Home, Tutorials: http://www.jxta.org