[jdev] S2S behind a gateway

[Reno]

Case:
I have a jabber server/router behind a gateway. that gateway is connected with 
DSL connection to WAN with multiple desktops on the LAN side (does that mean 
NAT?). Jabber clients can talk inside the LAN.

I have only the basic components installed in my XCP controller (CM, TC). 
Toiled through the help files but without example I'm afraid I can't go 
further.

Question:
How so users in my LAN can talk/transfer file with YM, MSN, other jabber users?
what components I need to install? and what are the configurations paramater?

Sorry if I ask too many, but I really feel lost. If anyone can point me to a 
website that'd be great.

Rgds,
Reno