Q:

Setting TCP Retransmission Timeout in C

I have an small server/client test program I am running over a radio link using TCP/IP and I noticed with wireshark that I am getting a lot of retransmits due to high latency.   How do I increase the window my program waits for an ACK before attempting retransmission? 
Update on OS:
The server is running Linux, the Client is on Windows

A:

In Linux, you can try playing with the TCP_WINDOW_CLAMP and the other options from http://lxr.linux.no/linux+v2.6.30/include/linux/tcp.h#L85 .  They can be set by using setsockopt (man 3 setsockopt), I think.