Using std wireless AP that comes with package? Have you tried direct connection to Optical Network Terminal?

You need to reduce variables in set-up. I was thinking that the wireless router has low processing speed and limited buffer. Why don't you try to connect direct to BTU. Check if still the same.

I'm not gamer but even for normal heavy downloading the TM AP always hanged at my brother's house. He bought something better but the name is not something likely most users heard of. He was having 20Mbps and also 10Mbps

Looks like this is common problem when I googled. Perhaps something to do with modem setup with Dota. Try read this

http://dev.dota2.com/archive/index.php/t-6482.html