Subject Connect to FB database through VPN

I have FB3 database at a customer site and was able to log in remotely because they had Port Forwarding set on their router for Port 3050 and I used the connection string - IP Address:Database Alias.  Now they have moved to a VPN (OpenVPN) and removed the Port Forwarding on port 3050.  I have setup OpenVPN on the remote computer and they have provided me with the clientbundle for the SSL stuff. I can open the VPN and log onto their server but when I try to connect to the database I get the error:

Unable to complete network request to host Failed to establish connection.

Is there something different I should be doing to connect to a FB database through a VPN?

Any help would be appreciated.

Bill Zwirs