In a local area networks using Ethernet technology, there may be switches, bridges and routers. Q4 (a) Explain the difference between a switch and a bridge. (b) Why are switches generally preferred to bridges except for the smallest networks? (6 marks) (6 marks) 4 marks) (c) How do routers operate differently from switches? ENGR8762 Computer Networks and Cybersecurity Q5 (a) 2018 Explain the difference between single-bit errors and burst errors in error control in communications systems. (3 marks) If a noise event causes a burst error to occur that lasts for 0.1 ms (millisecond) and data is being (3 marks) (3 marks) transmitted at 100Mbps, how many data bits will be affected? (b) Under what circumstances is the use of parity bits an appropriate error control technique