This might be the article: Success Center
This really isn't balancing, it's just using more than 1 Kiwi server to handle the load. We balance our servers using an F5(we already had it for other purposes). You could use round-robin DNS, HAproxy or possibly Windows NLB(never used it). The biggest issue with trying to load balance UDP is the session timeouts on the balancer. They should be zero if possible to remove any 'stickiness' with the connection. Otherwise the load doesn't get spread well.