computer networking: topic transport layer

$($a$)$ Suppose that the following four bytes are being sent via UDP:

$01101011001001011001101111010101$

Now answer the following questions:

i$.$ What will be the value of the checksum field in the UDP packet that is being

sent?

ii$.$ Suppose the first bit in the second byte of the data being sent is changed while

the UDP packet is being transmitted. How will the receiver know that the data

was corrupted? Explain your answer by calculating the checksum at the

receiver's end.

$($b$)$ A packet of length $1$ Mb is being transmitted from sender to receiver using a stop$-$and$-$

wait protocol where the window size is $5.$ The bandwidth of the connection between

them is $1\mathrm{.}5$ Mbps and the round trip time $($RTT$)$ is $600$ ms $.$ What will be the utilization

of the channel?

$($c$)$ In the case of a TCP connection, the sender sends two segments of data, the first one

with Seq$=92$ and $8$ bytes of data, and the second one with Seq$=100$ and $20$ bytes of data.

The sender receives a single packet with ACK$=120.$ What will the sender do in this

scenario?

$($d$)$ Explain the process in which a TCP connection is closed using a sequence diagram and

state changes.

$($e$)$ What is flow control? How does TCP implement flow control?

$($f$)$ Copy the following diagram showing the change in congestion window with each round

of transmission in a TCP connection using TCP Reno and mark the values of the size of

the congestion window for the next four transmission rounds. Assume that the initial

value of ssthresh before the TCP transmission is $8,$ and that there is no packet loss in the

next four transmission rounds.