Communicating with peers outSide LAN

I wonder if it is possible to communicate with peers on another LAN (with 
no NAT between networks)
I know that we can use RDV and Relay Peers do do this, but isn't it 
possible to do whithout.
Naturally, The multicast discovery can't pass through router :) 

For exemple I've got one LAN in 192.168.0.0 and another in 192.168.1.0
Peer1 is 192.168.0.10 and peer2 is 192.168.1.10

Assuming Peer1 knows IP address and port of JXTA on Peer2, how can I get 
Peer2 advertisement ?

If Peer2 as published a PipeAdvertisement, can Peer1 connect to him ?

If it is possible It will be wonderfull, I'll not have to use RDV and 
Relay :)

thanks

Cyrille

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Cyrille Folleau
Ingenieur Informatique
Tel : 01 41 38 42 37
Dassault Data Services
22 quai Gallieni
92156 Suresnes Cedex