High ms 24 men dungeons

[Farrrien]

I have problem with 24 men dungeons , only on them i have very very huge ms , fps are normal like 80-90 but ms 500-600 , before we start hit the boss is everything all right but when i start hitting the boss my ms goes to 600 ,after that my game crash( im sure its not my internet fault ,when im doing 6 men dungeons i dont have this problem) 
i have no idea how i can fix this :(

[Gigowatt221]

Trying a VPN could help you a lot reducing ping spikes like you have in 24 men dungeons. Any VPN could help you, but there are specialized VPN for gaming like WTFast and Pingzapper.

I don't have any link of a good free VPN to try it. I just know on that is free and good but it's localized in Paris (so... useful only if you're living in France) and there is no other servers available.