In order to achieve peak performance, SurfBouncer uses the UDP protocol to transmit data. Sometimes, an ISP will block UDP on their network in order to prevent encrypted traffic.
Additionally, there are times when network congestion and latency cause the UDP protocol to drop packets and even lose the connection. If this is occurring, you will see a 'Replay-window backtrack occurred' error in the log.
To resolve these issues, we operate TCP servers in addition to UDP servers . These servers operate on either port 80 or 443. We recommend port 443 as the first choice. Port 443 is rarely blocked. However, if port 443 does not work, try port 80. If you can surf the net, port 80 is open.
(NOTE: If UDP works, do not use the TCP servers as performance over TCP is normally not as good as over UDP.)
To switch to the TCP servers:
1 - Exit SurfBouncer OpenVPN, if you are connected
2 - Download the TCP configuration file below (right click and "save as")
3 - Use this file to replace the current file in your config directory
For users of the Windows 32 (XP) version of SurfBouncer, the location of the config directory is
C:\Program Files\SurfBouncer OpenVPN\config
For users using the Vista or Windows 7 32 bit version of SurfBouncer, the location is
For users using the Vista or Windows 7 64 bit version of SurfBouncer, the location is
C:\Program Files (x86)\OpenVPN\config
Now, launch the application and then right click on the GUI icon to select the TCP option
Log in as normal
Test the connection to determine if the problem is solved
For Mac users:
For Tunnelblick users using the beta versions prior to March 3, 2010, download the file and place in your home directory, 'Library', 'Openvpn' folder.
For Tunnelblick users with version 3.0 or greater, download the file and place in your home directory, 'Library', 'Application' 'Support', 'Tunnelblick', 'Configurations' folder
In some cases, the Mac will save the file with a '.txt' extension. Remove the '.txt' to use the file. The file name should end with '.ovpn'. After copying the files, exit Tunnelblick and restart it. (It may ask you for your Mac password before allowing for the VPN login to appear.
If the TCP server works, then there is nothing else for you to do.
You can switch between server types by disconnecting and selecting a different option. The SurfBouncer option is the default configuration. Your choices may look slightly different depending on how many options are installed on your system.