Re: unable to connect to server in multiplayer

Since you don't mention what you have tried, here's some universal solutions to most problems.
-Try restarting your computer and router
-Try repairing your game in Origin
-Try uninstalling and installing Origin again
-Try doing a UOtrace to EA's servers to check for problems - https://help.ea.com/article/how-to-uo-trace
-Update you drivers to your graphics card and other components.
-Check if Punkbuster is running correctly and update it manually (https://help.ea.com/article/battlefield-3-punkbuster-error)

Remember to accept the solution if it's correct and press the XP button if somebody helped.

Cheers
-Carbonic