When you have TOT Fiber and you need incoming connections from the Internet to your house (for example you do need Port Forwarding for example monitor Security Camera's or if you do torrents) please note that TOT has recently switched users over to Carrier Grade NAT.
What this means that ANY outside connection from the Internet (except of course Email and Web browsing etc) will fail.
What is Carrier Grade NAT:
https://en.wikipedia.org/wiki/Carrier-grade_NATSolution is to call TOT and ask to switch over to Bridge MODE (or as the Thai's say) BIT mode.
If you have no idea what I am talking about. Don't worry it means it doesn't affect you