Problem 1 (20%) 20 Mbps, 2 ms 20 Mbps, 2 ms 20 Mbps, 2 ms 20 Mbps, 2 ms A Figure 1: Two nodes A and B connected by three switches, Si, S2, and S3. Consider two nodes A and B connected by three store-and-forward switches S1, S2, and S3. The links connecting a node to a switch and a switch to another switch have the same bandwidth of 20 Mbps and a propagation delay of 2 ms as shown in Fig. 1. Assume that we have a packet of size 1 KB. Calculate the latency from first bit sent at A to last bit received at B for the following two scenarios: (a) Each switch begins re-transmitting after it has finished receiving the entire packet. (b) Each switch can implement "cut-through" switching; it is able to begin re-transmitting the packet after the first 400 bits have been received