Networking: delay in packet switching and circuit switching

    Communication between A and B in this network can be either packet switched (Based on "store-and-forward" principle) or circuit switched. Assume that a connection has already been set up between A and B. There are also other active connections in the network, e.g. between C and D shown in the figure. Explain the various contributions to delay through the network when we use a) line switching for an information unit sent from A to B. b) packet switching for an information unit sent from A to B.