Suppose there are two separate domains, one at SECRET (S) and one at Top Secret (TS), with a guard between them. Assume the guard is truly a "diode", allowing packets in only one direction. What direction will the guard allow traffic to flow? Suppose you want to move traffic in the allowed direction. Can you run an ordinary TCP connection through the guard to pass it through the guard? Explain why/why not, and if not, what protocol can you use to move the data?