Consider our motivation for correcting protocol rdt2.1. Show that the receiver, shown in Figure 3.57, when operating with the sender shown in Figure 3.11, can lead the sender and receiver to enter into a deadlock state, where each is waiting for an event that will never occur.
Consider the states of sender and receiver as follows:
Sender state as “wait for call 1 from above”.
Receiver state as “wait for 1 from below”.
Therefore, the sender repeats the sending packet with sequence number 1 and the receiver sends NAK again to sender. This raises a deadlock stage for both sender and the receiver.