Ok, so not too long ago, they upgraded my apartment block to a 10M infrastructure (glass fiber and all).
They gave me a new modem for the new technology. I spare you the issues that caused...
Now I'm in the situation that my router (airport extreme) is connected to the modem in bridge mode. 
The problem I have is that when I get home, my mobile devices (ipad, ipod, android devices) cannot get on the internet. The way I resolve that is by switching the modem off and on again (not the router!). My iMac doesn't have this problem. I really hate doing this. 

It seems like my modem "forgets" devices once they disconnect from the network for a while. There don't seem to be issues as long as all the devices are connected.

On my ipad its a bit worse because once that connects, I sometimes use the webex app for online meetings, and it seems like that app is considered a new internet connecting device, because it won't connect unless I reset the modem while the webex app is running.

Could this be related to my modem's settings? How can I get this fixed? I'm hesitant to call china telecom, because they will send a technician that doesn't speak english and he will reset the router and then considers the problem solved, and I end up calling them the next day again and everything starts all over again. Also, they do not carry laptops with them. this means they need to use my ENGLISH MAC, and considering they don't read english and don't know how to use Mac, this is an additional hinder to overcome and works counter productive in solving this. Note, I don't have a Windows Machine and will not buy one just in case there is a modem issue...

I'm sure it's just a setting on the damned modem, I just need to find out what it is, and how to change it.
Can anyone help?