tunneling UDP traffic over TCP-IP

I have a complex application which currently communicates between server nodes using UDP. This works perfectly for server-server traffic within the LAN cluster, but UDP traffic to external nodes is, unsurprisingly, hosed by various network factors. The easiest way to handle this problem (other ideas welcome) is to tunnel UDP traffic targeted to remote nodes over a persistent TCP-IP connection. What is the best and easiest way to do this? i.e. would it make sense to use netcat (nc), and if so what would be the best configuration…