Gce Model Questions Vol1 2020 Computer Studies Question 1

Consider a network of 8 computers. In the current star topology, each link between a computer and the central hub introduces a transmission delay of 2 ms and the hub adds a processing delay of 0.5 ms for each message it forwards. To broadcast a message from one computer to all the others, the originating computer first sends the message to the hub, after which the hub forwards it sequentially to each of the remaining 7 computers, one at a time. In an alternative full mesh topology, each pair of computers is directly connected; each direct link has a transmission delay of 1 ms and each computer's network interface adds a processing delay of 0.2 ms per transmitted message. Assume that in the mesh a computer can send the broadcast to all others simultaneously over the separate links. Calculate the percentage reduction in total broadcast time when switching from the star to the mesh topology. Give your answer to two decimal places.