friend gets disconnected after a while of playing.

hello, whenever I play with my friend who lives in the same country as me (Philippines) he gets disconnected either -- almost instantly as he joins or after a while. this didn't happen before -- now it's happening and its getting super annoying . > . , meanwhile my friends from abroad can join in and NOT get disconnected. why? is it like an internet problem of sorts? guessing it is.

--Update--

just saw that I needed to post system specs


here:

OS: Windows 7
Ram : 2GB
CPU : Intel Core...

friend gets disconnected after a while of playing.