The local connection capability works by creating a reverse ssh tunnel to crossbrowsertesting.com (216.37.72.238). This connection is initiated on your pc by a java applet which is launched when you start a local connection. You need to have the ability to initiate a tcp connection via port 22 (tcp) to crossbrowsertesting.com (216.37.72.238). This traffic will be ssh traffic. Your firewall administrator should be able to create a rule to allow you to initiate a tcp connection on port 22 to 216.37.72.238.