Suppose nodes A and B are on the same 10 Mbps broadcast channel, and the propagation delay between the two nodes is 325 bit times. Suppose CSMA/CD and Ethernet packets are used for this broadcast channel. Suppose node A begins transmitting a frame and, before it finishes, node B begins transmitting a frame. Can A finish transmitting before it detects that B has transmitted? Why or why not? If the answer is yes, then A incorrectly believes that its frame was successfully transmitted without a collision. Hint: Suppose at time t=0 bits, A begins transmitting a frame. In the worst case, A transmits a minimum-sized frame of 512+64 bit times. So A would finish transmitting the frame at t=512+64 bit times. Thus, the answer is no, if B's signal reaches A before bit time t=512+64 bits. In the worst case, when does B's signal reach A?

Suppose nodes A and B are on the same 10 Mbps broadcast channel, and the propagation delay between the two nodes is 325 bit times. Suppose CSMA/CD and Ethernet packets are used for this broadcast channel. Suppose node A begins transmitting a frame and, before it finishes, node B begins transmitting a frame. Can A finish transmitting before it detects that B has transmitted? Why or why not? If the answer is yes, then A incorrectly believes that its frame was successfully transmitted without a collision. Hint: Suppose at time t=0 bits, A begins transmitting a frame. In the worst case, A transmits a minimum-sized frame of 512+64 bit times. So A would finish transmitting the frame at t=512+64 bit times. Thus, the answer is no, if B's signal reaches A before bit time t=512+64 bits. In the worst case, when does B's signal reach A?

Principles of Information Security (MindTap Course List)

6th Edition

ISBN:9781337102063

Author:Michael E. Whitman, Herbert J. Mattord

Publisher:Michael E. Whitman, Herbert J. Mattord

Chapter6: Security Technology: Access Controls, Firewalls, And Vpns

Section: Chapter Questions

Problem 2RQ

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Suppose A and B nodes are on the same 10 Mbps broadcast and the propagation delay is 325 bit times between the two nodes. Suppose for this channel CSMA/CD and Ethernet packets are used. Suppose node A begins sends a frame and node B starts sending a frame until it is over. Can A finish transmitting B until it is detected? Why not? Why or why not? If so, then A incorrectly insists that his frame was transmitted safely without a crash. Hint: Suppose t = 0 bits at the moment, A begins sends the frame. In the worst case, a minimum frame of 512 + 64 bit times is transmitted. So A would end the frame at t = 512 + 64 bit times. The . response is no, if the signal B crosses t = 512 + 64 bits before bit time. In the worst scenario, when does B hit A?
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