Problem:

Suppose two nodes, A and B, are attached to opposite ends of an 800 m cable, and that they each have one frame of 1024 bits (including all headers and preambles) to send to each other. Both nodes attempt to transmit at time t = 0. Suppose there are five repeaters between A and B, each inserting a 20-bit delay. Assume the transmission rate is 10 Mbps, and CSMA/CD with backoff intervals of multiples of 512 bits is used. After the first collision, A draws K = 0 and B draws K = 1 in the exponential backoff protocol after sending the 48-bit jam signal.

a. What is the one-way propagation delay (including repeater delays) between A and B in seconds? Assume that the signal propagation speed is 2*10^8 m/sec.

b. At what time (in seconds) is A's packet completely delivered at B?

c. Now suppose that only A has a packet to send, and that the repeaters are replaced with switches. Suppose that each switch has a 16-bit processing delay in addition to a store-and-forward delay. At what time, in seconds, is A's packet delivered at B?

Note: you must include all the delays occurred according to CSMA/CD protocol.

Additional Information:

This question is from Computer Science as well as particularly to Networking. The question here is about colliding signals in cable and the methods employed to rectify errors caused by this and to transmit information correctly.