1. In rdt 2.0, explain the following a. When is an ACK sent by a receiver's transport layer b. When is a NAK sent by a receiver's transport layer? c. What does a sender's transport layer do when it receives a NAK? (1 point) (1 point) (1 point) 2. Explain in your own words why sequence numbers need to be added to the segments sent by the sender in rdt 2.1 (3 points) 3. Assume the following parameters for rdt 3.0 (6 points) a) Round Trip Time (RTT)10 ms b) A segment is 1500 bytes. c) Timeout interval -2 Suppose that Bob sends 3 segments to Alice using rdt 3.0 with the first segment numbered 0, the second segment numbered 1, and the third segment again numbered 0. Suppose the following happened during the communication process . The first segment (i.e.. segment numbered O) arrived at Alice correctly. The feedback for this segment also arrived at Bob correctly . The second segment (i.e., segment numbered 1) was lost when it was sent by Bob the first time, but arrived at Alice correctly when it was retransmitted. Any feedback sent by Alice to Bob corresponding to this second segment, however, arrived at Bob . The thirdsegment (i.e., segment numbered 0) arrived at Alice correctly. The feedback for this segment also arrived at Bob correctly What is the throughput obtained in sending all the segments to Alice in bytes/sec)? Draw a diagram to show your work in detail