Large File transfer from Flex client to C++ server through UDP

I am trying to buil开发者_如何学God a UDP application(P2P) of Large file transfer in Flex. My back end is C++. How can I transfer my client's files to server without any middle server. If I use stratus services..how to connect that to C++. Please help me, if possible with source code. Thank you.

Why would you choose to use UDP for a large file transfer?

Look at the FTP protocol.
This problem has already been solved.