I have a Nortel VPN Client connecting to an external server from our office network. The internet connection was previously connected to a Cisco 2811 Router and a single IP address was used to translate all internal IP addresses for internet access. Now we just installed a Cisco PIX 515 Firewall and same translation was done using the single IP Address on the Outside interface of the Firewall. But i noticed that though the VPN client still connects, after a while it gives an error and disconnects. Any idea what could be the cause of this? Thanks.