Problem
1. Show the bidirectional FSMs for the simple protocol using piggybacking. Note that both parties need to send and receive.
2. Show the bidirectional FSMs for the Stop-and-Wait protocol using piggybacking. Note that both parties need to send and receive.
3. Show the bidirectional FSMs for the Go-back-N protocol using piggybacking. Note that both parties need to send and receive.