Best approach for integrating with thrid party servers

I am the creator of an open source multiplayer game engine, and have a couple of questions I was hoping those familiar with UDK could help answer.

I’m looking for the best way to provide integration with UDK. The server supports udp and tcp and the protocol is simply standard protocol buffer messages. All reliable messaging and other similar functionality is provided at a higher level. So the client needs to be able to just speak plain udp/tcp.

So does UDK have existing networking abilities I can leverage for this case? and If not, are there preferred networking libraries you would want to see used?

Chris