Imagine using the stop-and-wait protocol to guarantee a reliable data transfer over a lossy channel with bit errors.

a. Draw a diagram showing that if the network connection between the sender and receiver can reorder messages (that is, that two messages propagating in the medium between the sender and receiver can be reordered), then having only sequence numbers 0 and 1 can cause the receiver to receive old data in place or new data. Your diagram should have the sender on the left and the receiver on the right, with the time axis running down the page, showing data (D) and acknowledgment (A) message exchange. Make sure you indicate the sequence number associated with any data or acknowledgment.

b. Compute the sender utilization for this protocol in the case the round trip time between sender and receiver is 7 ms, the network throughput is 1Mbps and each packet has a size of 1500 bytes. (ms=milliseconds)

c. Imagine now using a pipelined protocol. How big would the window size have to be for the sender utilization to be greater than 98 percent?