Exercise 1. Consider a network between client and server, consisting of four links in the path represented by R1, R2, R3, and R4 similar to the figure given below.The transmission rates of the four links are R1=1Mbps,R2=3Mbps,R3=2Mbps,R4=5Mbps. Please answer the questions below for the scenario of the server sending a file to a client. 1. What is the throughput for the file transfer? (You can safely assume that there is no other traffic in the network) 2. Suppose the server wants to send a file of size 8millionbits, how long will it take to transfer the file to the client? 3. Repeat parts (1) and (2), but now with R4 reduced to 500kbps