then you must use DHCP reservation to save all the users ..and in virtual server ( or port forwarding ) block it except for your dad's
How can we do that? Please explain more, I'm not really a professional in this. Sorry for all the questions!
It didn't help a lot since the firmware of the router in the link is old.. Mine is 3.11.7 Build 100603 Rel.56412n
the first thing you do is update the firmware .. then install teamviewer 7 on your pc and pm the user and password so i can log into your pc .
8 days later
There is a much easier way. Your TP-link router has IP bandwidth control
http://www.tp-link.com/en/products/details/?model=TL-WR741ND#over
(I use it for my TP-link router to limit internet speed for each user).

Go to the router settings, bandwidth control control setting, choose enable, line type adsl and put engress (upload speed) and ingress (download speed) of your connection. Press save. Then go to rules list, click add and put all ips other than yours to a low max speed and min speed 1. I usually put all dhcp clients at low speed and I use static ip not in dhcp range for my pc (since your ip changes from time to time in dhcp). Also put a min speed limit for your ip and max ip the whole connection speed.
Limiting Internet Usage on phone can be done in a more complex way for example using hotspot from MikroTik and limiting user Upload/Download Speed and even controlling the bandwidth he/she can use per day .
@khatib1 you are right .. i didn't know the router can do this without a different firmware