One day i need to communicate with my friend through internet which is not with my network. I found the software team viewer. its very interesting. Its very simple to use also. Just open the software and generate the code for you host (computer). Get the team viewer generated password which host you want to connect. then paste then code and click connect. But its only one way communication.
Above i taken the screenshot of the software.You can view very clearly. Rightside you can see two box ID and password. thats for you host. and left side one box thats for you need to paste the ID of which host you need to connect.
If you need that software download it.