Usually Cpanel can be opened from:
https://mydomain.com:2083
http://mydomain.com:2082
http://cpanel.servername.com
Many times local firewalls allows access only to sites on Port 80. In such cases you can use http://cpanel.servername.com
Note:http://cpanel.servername.com is the web based proxy which provides you the option to access your cPanel via http port 80
You can execute the following commands to check if the ports are blocked.
For Windows
-Click [...]