4. a) Four datagrams, each of 500Kb leave for the destination one after another. However, they travel through different paths as shown in the following table: [8] Datagrams Path Length Visited Routers 1,2,5 1,4,3,5 12,700 Km 9,700 Km 3,200Km 12,200 Km 3 1,3,5 1,2,3,5 4 We assume that the delay for each router (including waiting and processing) is 10, 3, 20, 7, and 20 ms respectively. Assuming that the propagation speed is 2 x 10^8 m, find the order the datagrams arrive at the destination and the delay for each. Ignore any other delays in transmission. Page 5 of 5 b) Suppose, we have a circuit switched network which requires a setup time of [7] 2ms and a termination time of ls. Exchange of 1200 kbits takes place in between the setup and teardown phases. If the distance between two parties is 5000 km and the propagation speed is 2 X 10^8 m and bandwidth of the network is 10Mbps, what is the total delay for the entire procedure