Networked Game play

In a section of my subnet a number of users are playing a networked game called Unreal Tournament and i’m trying to monitor bandwidth usage and volume of traffic.

I’ve run a network monitor from Microsoft SMS and the usage seems very low despite having 30 users, 10 playing the game, and normal network traffic and i can’t identify the users i know who are using the game either by ip or mac address.

All 30 hang off a cisco 3624 switch.

I would like to try & stop all this traffic or at least have an accurate assessment of what resources it is using

any suggestions on how to improve our security