FRM-92050 Java.net.NoRouteToHostException: operation timeout

Hi,
i got the problem when i try to access the applications via VPN.
release 1159 in linux server

FRM-92050 Java.net.NoRouteToHostException: operation timeout

FRM-92050 Failed to connect to the server

Within the LAN, everything is fine; users can connect to form server. But when users connect externally (Internet) using proxy authentication (squid), they got FRM-92050 error. (details: Java.net.NoRouteToHostException: operation timeout.).

any tips?

thanks,
peri sekar