Consider this network topology: A ---> S -----> B with two hosts (A and B) and a switch S that uses store and forward technique. Use this notation: d(x,y) = distance between nodes x and y v = signal propagation speed N = packet length, in bytes Tq(x) = queuing delay at node x. Assume for all nodes x that Tq(x) 0. R = data rate, same for all links, in bps a) Write the formula for TAB, the delay between the transmission of the first bit of a packet at A and the reception of its last bit at the destination, B. b) What is the formula for TAB if the topology changes to one where between A and B there are n switches with identical Tq, all link data rates are equal to R, and all link lengths are equal to d ? A -----> S1 -----> S2 -----> .......... -----> Sn -----> B c) A network designer has to select a technology for the topology from part b) with the proper minimum data rate Rmin so that TAB Tmax, for a given Tmax. Determine the formula for Rmin as a function of all other parameters, including n and Tmax