There are many reasons why you might need to determine what process is using a particular port or, conversely, what port(s) a particular process has open. There are also a number of tools such as lsof ...

Port forwarding is a crucial networking technique that allows you to make a computer or device on your local network accessible to the internet, bypassing the security features of your router. This is ...

You could try telneting to port 139 from an outside machine. If you get anything other than an access denied, you likely have an open port.