Minecraft Freezing Suddenly during multiplayer

Hi, I would like to know if there is a fix to a problem during multiplayer playing, every time that I go onto a server every 30 minutes it freezes for an unknown reason, I wait for the game to unfreeze, but it doesn't do anything, I even try pressing alt and f4, but it even freezes my whole computer, please if there is anything to make this bug stop I would be delightful to know a possible way, I hope this information was valuable, thanks.