One of most asked questions about internet sharing is "How to control bandwidth for a specific user"... there are some firmwares like Tomato etc. for this purpose but they support very few routers and are difficult to understand...
You cannot always say NO to your dear neighbors, when they ask for your wifi key... and people are always greedy to exploit free facilities :/
I bought TP-Link TL-WR740N router from Rawalpindi Saddar, for 2800 PKR, six months back.
You can easily control bandwith with it ...
here is screen shot of the people using my wifi, only one is my computer, all other are brother, sisters and neighbor's devices, so in this situation i really need to limit their bandwidth.
How to Control Bandwidth...?
You can control bandwidth of a specific user or all users, however i suggest to reserve unlimited bandwidth for your devices.... and limit bandwidth of all other devices...
In DHCP List of the router, it displays MAC address of all devices connected to the router...
Click address reservation and reserve ip under 100 for your own devices, e.g 192.168.1.50 etc (reserve IP for those devices you wish to provide all available bandwidth)
Like i have reserved IPs for five devices which are in my own use.
then go to Bandwidth control > Rules list,
and For ip 100-required, put desired download and upload speeds in kbps... like i have allowed 40 kbps (5KBps)
router's, default settings start IPs from 100... so only reserved IPs under 100 will get maximum speed.
Dont forget to change router's setting page password in "System tools".
so now i happily give key to my neighbors to use my wifi.
I hope this will be helpful for you.
if you have any query, you can ask here.