1. Suppose two hosts, A and B, are separated by 20,000 kilometers and areconnected by a direct link of R =2 Mbps. Suppose the propagation speed overthe link is 2.5?10^8 meters/sec.a. Calculate the bandwidth-delay product, R?tprop.b. Consider sending a file of 800,000 bits from Host A to Host B. Suppose thefile is sent continuously as one big message. What is the maximum numberof bits that will be in the link at any given time?c. Provide an interpretation of the bandwidth-delay product.d. What is the width (in meters) of a bit in the link? e. Derive a general expression for the width of a bit in terms of the propagationspeed s, the transmission rate R, and the length of the link m.