The port may be closed as the modem / router and the provider side. In addition, it can be blocked by your firewall. Using standard Windows tools, you can check whether the closed port that the program uses for its operation.
In order to check open/closed ports in Windows, you must use the command line. To run press the key combination "Windows+R". After these steps, a window will open. It is necessary to enter "cmd". Then press "Enter".
The screen will appear a black window, which experts call the Windows command prompt. You can now run the very tool that will allow you to view a list of closed ports. Enter in the command prompt "netstat".
After typing, press "Enter". In the command prompt window will display information about all the open ports on your computer. This will be followed by the domain name of your personal computer and are separated from it by a colon. Note that all portsthat are not specified in this list are private. And if a port that your app uses included in this list, it will be necessary to close the application is able to function normally.