A LAN based upon IEEE 802.3 CSMA/CD 10Base2 is used to carry data between two computers located/cabled 15m apart. a) If a simple connectionless service is employed by LLC, how long will it take to transfer a 1 Mbyte file between these devices if no other devices are using the network? Assume a 9.6Sec inter-frame gap and maximum frame size. b) How long with the file transfer take if the LLC uses an acknowledged datagram service? c) If other devices are now using the network such that each frame is subject to an average of 4 collisions, estimate the time taken to transfer the 1 Mbyte file using the unacknowledged LLC service. Determine the file transmission times for duplex transmission over High Speed and Gigabit Ethernet for frame sizes of 248 and 1500 octet payloads. Contrast these with the times obtained in parts a, b \& c, and for half-duplex High Speed and Gigabit Ethernet when the chances of a collision occurring are zero, the same as c) and reduced by a factor of 10