CP5601 Assignment 1 – 2010Question 1 [2 marks]: In token ring network, each station interface in listen modeimposes a constant delay (minimum of 1-bit delay) between its input line and outputline.a. Is there any effect on the delay if data frames are removed by receiver instead oftransmitter? Discuss.b. Suppose some stations in a token ring network may be power down at night,and the corresponding delay in the station interface is removed. Is there anyconsequence on the operation of the token ring network. Discuss.Question 2 [2 marks]: Consider the following method for congestion control in a errorfreevirtual circuit subnet. A router can only send ACK for a received packet if it knowsthe packet transmission along the virtual circuit through subsequent routers issuccessful. Suppose that each router uses stop-and-wait ARQ and provides one buffer(large enough for one packet) for each VC in each direction of traffic. If each router takesT sec to transmit packet (data or ACK) to the next router and there are N routers on theVC, at what rate data packets are delivered to destination host?Question 3 [3 marks]a. Compare the operation of stop-and-wait ARQ and bidirectional GBN ARQwith window size of 1. Sketch out a sequence of frame exchanges using thesetwo protocols and observe how the protocols react to the loss of an informationframe and to the loss of an ACK frame.b. In selective repeat ARQ, is it desirable to send multiple NAK repeatedly for thesame frame? Explain. If not, how can it be avoided?c. Is NAK essential in selective repeat ARQ (affecting the correctness of theprotocol)? Explain.Question 4 [3 mark]: Read the following two papers. Summarise in your own wordstheir approaches to IPv4/6 transition:• M. Mackay and C. Edwards, “A Managed IPv6 Transitioning Architecture forLarge Network Deployments ” IEEE Internet Computing, pp. 42—51, Jul 2009.• M. Park, J.-T. Kim, E.-H. Pail and K.-R Park, “Deployment Strategy andPerformance Evaluation of the IPv6 Home Network using the Home Server”IEEE Transactions on Consumer Electronics, vol. 53, no. 1, pp. 114—119, Feb2007.