Host A and B are communicating over a TCP connection, and Host B has already received from A all bytes up through to byte 280. Suppose Host A then send two segments to host B back-to-back. The first and second segments contain 120 and 150 bytes of data, respectively. In the first segment, the source port number is 503, and the destination port number is 80. Host B sends an acknowledgement whenever it receives a segment from host A.

a)In the second segment sent from Host A to B, what are the sequence numbers, source port number, and the destination port number?

b)If the first segment arrives before the second segment, in the acknowledgment of the first arriving segment, what is the acknowledgement number, the source port number and the destination port number?

c) If the second segment arrives before the first segment, in the acknowledgment of the first arriving segment, what is the acknowledgment number?

d)Suppose the two segments sent by A arrive in order at B. The first acknowledgement is lost and the second acknowledgment arrives after the first timeout interval. Draw a timing diagram, showing these segments and all the other segments and acknowledgments sent. Assume these is no additional packet loss. For each segment in your figure, provide the sequence number and the number of bytes of data; for each acknowledgement that you add, provide the acknowledgement number.