UDP packets to PC behind NAT

[Christophe]

Janto Dreijer a écrit :
> This is probably more of a networking question than a Python one, but
> it would be nice to know if someone has done this with Python's socket
> module. And besides one usually gets more information from c.l.py than
> anywhere else :)
> 
> I have a server with a static "public" IP and a client behind a NAT. I
> would like to send UDP packets from the server to the client. So what I
> need to do is open up a "hole" in the NAT and let the server know the
> target IP and port of the client where it can send its packets.
> 
> Now I have read somewhere that you can have TCP and UDP running on the
> same port. Not sure if this is true. Would it be a reasonable solution
> to initiate a TCP connection from the client to the server and somehow
> (?) let the server figure out how the client is connecting? And then
> send UDP to client over the same (IP, port)?

Initiate an UDP connection from the client to the server and have the 
server send back the UDP packets to the address you get in the 
"recvfrom" result.