如何确定由于中间网络断开而导致TCP套接字死机所需的最长时间？

I have a program in C++, using the standard socket API, running on Ubuntu 7.04, that holds open a socket to a server. My system lives behind a router. I want to figure out how long it could take to get a socket error once my program starts sending AFTER the router is cut off from the net.I have a program in C++, using the standard soc