Firewalls create barriers in order to prevent unauthorized access to a network. A firewall is a system or group of systems that enforces a control policy between two networks. Firewalls exist to welcome incoming traffic as well as to block traffic. Firewalls exist in both software and hardware form.
If you have a firewall installed on your system you may need to have the firewall grant access to Dark Age of Camelot. Please refer to your firewall manual for further instruction.