What is a port?

Posted on March 17, 2015 @ 8:42 pm

"In computer networking, a port is a software construct serving as a communications endpoint in a computer's host operating system. A port is always associated with an IP address of a host and the protocol type of the communication. It completes the destination or origination address of a communications session. A port is identified for each address and protocol by a 16-bit number, commonly known as the port number which ranges from 1 to 65535." Source: en.wikipedia.org

An example for the use of ports is when you are browsing the web/internet. By default, HTTP uses port 80 and HTTPS uses port 443. When you open a website through your browser, your computer connects to the website's server through port 80, all communication and data is then passed through that connection. Another is the domain name system (DNS) which uses port 53 and Simple Mail Transfer Protocol (SMTP) that uses port 25 now if the administrator of your network doesn't want you to send emails all he/she have to do is block or close port 25 on the network's firewall or port 80/443 if he/she wants to stop you from browsing the internet

In layman terms a port is like the doors on your house, you can walk through a door to go to other places. If you do not want anyone to enter your bedroom all you have to do is close and lock your door. Now if you are getting the "No open port found" error this means that DroidVPN cannot find any open port to connect to our servers. It basically means that your current ISP(eg: Airtel) is blocking your device to communicate to other devices outside your network. This normally happens if you do not have a data plan on your mobile phone or you are connected to a severely restricted WiFi network (Eg: School WiFi). If you do not have a data plan your ISP blocks all ports since they are expecting you to not use your internet connection.

TIP: You can also visit our Recommended settings page to see what port settings are currently working for your ISP and Country.

Related article: Cannot connect because port X is closed