Lag issue only on bg

As the tittle says im only having lag problem in bg, when im in city, leveling,dungeos,raids i Play good considering my zone, not lag At all, but as soon as i enter bg my ms goes to over 500 till 900 or more sometimes, i tested It on morning, afternoon and night with lowest population and its the same, all battlegrounds turn unplayable. And is a problem since is the more i like to do.
Any help, suggestions, ideas of what night be causing this. Im not lossing package and i dont use addons.

I got hit by this in 4 out of 6 bgs I was in, ranging from 10 seconds to a full 25 seconds, which is frustrating.

Bump...
No gm,mod,develop reply? Thanks for da help.
I know that if im laggin And server works fine, might be an issue on my net, but why only on battlegrounds? To the point i cannot move, use a skill, like on 5-6 secs delay is a diferent hosting?