1. Suppose that Bob sends 450,000 bits to Alice over a 2.4 Kbps link (note l Kbps 10s bps) that uses circuit switching. Suppose that circuit ented using TDM, that a frame is 1 sec, and that a frame consists of 8 slots. Bob is assigned one slot in every trame. How many minutes does it take Bob to transmit all bits to Alice? (8 points) switching on the link is implem 2. Suppose that Router A and Router B are connected via a 10 Kbps link, and that the two routers are 20 meters apart. Suppose that Router A is transmitting a packet, and that there are 7 additional packets in the queue of the router, when a new packet arrives at Router A. Suppose that 500 bits of the currently-being-transmitted packet has been transmitted by Router A. Also, assume the following a. Every packet consists of 1000 bits. b. Propagation speed of a bit over the link connecting the two routers is 2 x 103 meters/sec. c. Processing delay of a (whole) packet at a router takes 1 millisecond (i.e., 0.001 seconds). What is the total delay of the new packet, i.e., how long does it take the new packet to arrive at Router B from the time it arrived at Router A? In your solution, clearly identify all four delay components the new packet (10 points) experiences 3. What are the five layers in the Internet protocol stack? Explain also itn your own words the principal responsibilities of each of these layers. (10 points)