Alexander,
By default there's no timeout. You need to call
NutTcpSetSockOpt() to set the timeout in
milliseconds. Here's an example for 5 sec timeout:
u_long to = 5000;
if(NutTcpSetSockOpt(sock, SO_RCVTIMEO, &to, sizeof(to)))
NutPrintString(0, "Sockopt TO failed\r\n");
Harald