Suppose that L bits of user data are to be transmitted through m switches in a packet switched network as a series of packets, each containing n data bits and h header bits with L being much greater than each packet. Assume that each link on the path could transmit r bits per second; the per-hop propagation delay is t; and processing times are negligible. What is the total message delay from the source to destination (you can assume that this user data transfer is the only service in the network)? Given the user data size L, what fragment size n would give the minimum delay (you can use some kind of approximation if necessary)? (Hint: The message can be recovered only when all fragments of the message are received at the destination; and the message delay is the time between the start of the source transmission to the reception of the last packet.)