To add onto Rod's reply, the SmarterStats service uses a standard TCP port that should listen on port 50003. You should be able to telnet to this port from the SmarterStats primary server to the remote server IP.
You'll want to run the following command in a CMD prompt on the remote server:
netstat -anbp | tcp
You should see the IP address of your remote server listening on port 50003 with the process owner being sssvc.exe, if not, please ensure the service is running. If the service is running, the process may be failing to bind to the IP address.
If this is the case, we would recommend opening a support ticket with us so we can further troubleshoot the issue with you.
I hope this helps.
Technical Support Specialist / Internal IT