8. (6 marks) Host X wants to send a large file across the Internet to host Y. There are three intermediate links between the two hosts. Link 1 has a rate of 500 kbps, Link 2 has a rate of 2 Mbps and Link 3 has a rate of 1 Mbps. (Show your work) a) Draw a rough labeled sketch of the network. b) What is the throughput for a file transfer? c) If the file is 4 Mbits, how long with it take to transfer to host Y? (no delays or loss) d) What is the throughput and transfer time if Link 2 is reduced to 100