Hosts A and B are each connected to a switch S via 10-Mbps links as in Figure

Question:

Hosts A and B are each connected to a switch S via 10-Mbps links as in Figure 1.21. The propagation delay on each link is 20 µs. S is a store-and-forward device; it begins retransmitting a received packet 35 µs after it has finished receiving it. Calculate the total time required to transmit 10,000 bits from A to B:

(a) as a single packet.

(b) as two 5000-bit packets sent one right after the other.

Figure 1.21