UDP通信

Virtual Connection over UDP
http://gafferongames.com/networking-for-game-programmers/virtual-connection-over-udp/
http://stackoverflow.com/questions/11885331/reasonably-reliable-udp-broadcast-library-protocol?lq=1
https://code.google.com/p/openpgm/
http://arstechnica.com/civis/viewtopic.php?t=225466&start=40