Using UltraVNC instead of TeamViewer
Sebastian Wright 
I have happily using TeamViewer over the internet for some time - perhaps too long because it just told me I must pay for the commercial version (too expensive for me). So I'm trying to find an alternative. I then tried UltraVNC which looked promising - I installed it on two PCs on my home LAN and it worked straight away. But then I realised that the address I used was a local one "192.168...etc" I presumed it would be no trouble at all to switch to using a WAN address but I can not find any documentation on it. I did find a couple of things that sort of hinted at a solution but they were full of jargon I didn't understand.
So now I am after - either a not-too-complicated way to arrange for a WAN address or perhaps a different alternative to TeamViewer that will work over a WAN.
1 Answer
UltraVNC (like many other VNC applications) doesn't have the capabilities as TeamViewer because TeamViewer (and the like) route themselves out to the Internet over HTTPS (so they can circumvent firewalls) but, and the most important thing to remember about the likes of TeamViewer is that they are clients that connect to a remote management server that deals with the connection requests and then makes the connections between users. Much like a telephone exchange - you dial a number and the exchange (which isn't at your location) makes the connection to the recipient. Notice on TeamViewer that, to connect to a remote machine, you have to enter a unique ID and PIN? This is, essentially, the telephone number of the remote device that your remote user tells you and then gives you the PIN to ensure the connection is private to only those who know the PIN.
UltraVNC (and the likes) don't have the functionality to automate the routing out the the Internet so you have to manually forward ports on your router to the computer you wish to control. This port forwarding is the same for any other port forwardwing requirement. Be warned, however, that opening ports to the Internet is dangerous. It is best to use a VPN so that you can create a secure tunnel to your location. You would only need to open the VPN port as, once connected to the VPN, you would, typically, have full access to your network as if you were at that location.
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