I am not entirely sure about this, but I don't think you generally have to worry about a suspended process having its network connections dropped due to a tcp keepalive timeout. I think the kernel will continue to service the connection (including generating and responding to keepalive packets) as long as the socket connection exists regardless of the state of the process (running, suspended, sleeping, blocked on I/O, etc.)

In any case, this is very easy to test: just run tcpdump while your program is suspended and see if there are keepalive packets generated.