Online game backend architecture using mono

I need to write backend for a flash game. The game it self is not complicated. The game itself is a small session(around 2 minutes long) but there are many sessions active at a time. What I though of is making a gateway server which accepts connections and multiple servers that host game sessions. Gateway will tell the game server to create new game session and will forward all messages to it's message queue. Game server will process it and reply back to gateway, which in turn will send response back to the client. I want to do this using mono and run on linux as daemons. Can you give opinions about how to make this architecture better?

UPD: The game is not realtime and avg packets per second from a single game开发者_运维知识库 session will be around 5-15. Game session has 2 to 4 players. They all have average size of around 10 to 50 bytes. Udp is possible but will be an overkill, so it will to go with tcp.