a) Your team is implementing the RDT3.0 reliable layer for a File Transfer application. To help the team to understand the RDT3.0 logic for the sender and the receiver, your team leader creates the following table that lists possible events experienced by a peer. Please complete the table. For the Action column, provide descriptive information to describe what the peer would do in response to the event at that state; the team will use the information to implement the program logic. For the Next State column, give the state of the peer after the event. We have completed the first row as an example for your reference.

Peer	Current State	Event	Action	Next State
Sender	seq# = 0	Upper layer calls rdt_send() to pass a message to rdt layer.	Build a packet with seq# 0 that contains the upper layer message, compute the Internet checksum of the whole packet, and add the checksum to the packet. Call udt_send() to send the packet and then start the retransmission timer. Buffer this packet for retransmission.	seq# = 0 wait for ACK
Sender	seq# = 0	Lower layer passes an ACK with seq# 0 to rdt layer.
Sender	seq# = 0	Lower layer passes an ACK with seq# 0 to rdt layer.
Sender	seq# = 0 wait for ACK	Lower layer passes an ACK with seq# 1 to rdt layer.
Sender	seq# = 0 wait for ACK	Timeout
Sender	seq# = 0 wait for ACK	Lower layer passes a corrupted ACK with seq# 0 to rdt layer.
Sender	seq# = 0 wait for ACK	Lower layer passes an ACK with seq# 0 to rdt layer.
Receiver	Expectseq# = 0	Lower layer passes a corrupted message with seq# 0 to rdt layer.
Receiver	Expectseq# = 0	Lower layer passes a corrupted message with seq# 1 to rdt layer.
Receiver	Expectseq# = 0	Lower layer passes a message with seq# 0 to rdt layer.

Receiver

Expectseq# = 0

Lower layer passes a message with seq# 1 to rdt layer.

b) Consider the above RDT3.0 protocol is running on a link with 1 Mb/s transmission rate and the propagation delay between two peers is 1 ms. In your design, you add a 10-byte header to the data packet and the packet can carry at most 1500 bytes of payload. The ACK packet is of size 10 bytes as it contains header information only. i. Given the above operation parameters, calculate the best channel utilization rate for this RDT3.0 protocol on this network. Channel utilization is defined as the fraction of time the channel is busy transmitting bits in the channel. Include the acknowledgment packet in the analysis. ii. Consider transferring a 3 106 bytes file from the sender to the receiver using the above protocol. Assume the transmissions are error-free, find the best application file transfer throughput. iii. Assume your RDT3.0 protocol adopts a fixed retransmission timeout duration of 3 ms and the network has an error rate of 1%, i.e., one packet loss/corruption out of 100 transmitted packets. Estimate how long it would take to transfer the same 3 106 bytes file and calculate the result application throughput. Please note that from part a) above, the retransmission timer is started right after the RDT layer sent the data packet.