Problem 4 a) In the following scenario where a telnet session on a TCP Connection is going on between host A and host B, what is the sequence number and Ack number of the segment going from host B to host A? Host A Host B User types C Seq=42, ACK=79, data = 'C host ACKS receipt of 'C, echoes back C Seq=?, ACK=?, data = 'C' simple telnet scenario b) Consider the Go-Back-N protocol, and suppose that base of the senders window is X. Is it possible for the sender to receive an ACK for a packet that has a smaller sequence number than X. If so, sketch out a timeline-diagram showing sender and receiver messages sent and received that shows how this is possible. If not, explain why this can never happen