5. Answer the following questions. [10 marks] 1) For the checksum mechanism used in UDP, suppose you have the following three 16-bit hexadecimal numbers: EA53, F74B, D068. What is the checksum value of these three numbers when presented as a hexadecimal number? [5 marks] 2) Consider the selected repeat (SR) protocol. Given the sequence number space is [0, 10], what is the largest allowable window size that can make the SR protocol work properly? Generalize your result for the sequence number space [0, k]. Give your justifications. [5 marks]