I'm running a game server for my mobile game. It runs as a Java 8 application and uses Kryonet. It uses both UDP and TCP quite oftenly - UDP for spamming update packets and TCP for shooting and a few other events. TCP and UDP uses different ports, not the same one.
I'm currently running 3 game server application instances, every on different ports of course.
Linux server runs on VPS, stock Ubuntu 14 with a few packages installed. Some players are crying, that they have high ping(> 100), even though they can play other games online well. I am aware, that location plays a big role, this question is not really about it.
What could I do? Is my OS choice bad?