TCP sender TCP receiver t-3 t-4 lost lost t= 10 1-11 12 . 5 points (a) (5 points

ID: 3746253 • Letter: T

Question

TCP sender TCP receiver t-3 t-4 lost lost t= 10 1-11 12 . 5 points (a) (5 points) With respect to the diagram above showing a series of packets sent be- tween a TCP Sender and TCP Receive, with two segments being lost in transmission: Fill in the missing elements in the table below, providing the sequence numbers and time ACK segment is sent where applicable. Provide a brief explanation for the ACK field value The initial value of the sender-to-receiver sequence number is 105, and each segment contains exactly 405 bytes. TCP Segment Time segment Sender to Receiver Time segment received Receiver-to-sender sent (t)sequence no. value and ACK value sentACK field value Segment 1 Segment 2 Segment 3 Segment -4

Explanation / Answer

TCP Segment

Time Segment (t)

Sender to Receiver Segment No

Time Segment received and ACK value sent

Receiver to sender ACK field value

Segment 1

105

Segment 2

106

Segment 3

107

Segment 4

108

From the given figure, we can determine the time on which segment is sent and the time at which segment is received.

As we can see that segment 3 & 4 is lost, so there will be no acknowledgement for these segments.

The sender will not send next segments until it receive the desire acknowledgement (in this case ACK for segment 3). Sender will wait for TTL (time to live) time and again tries to resend segment 3.

If the sender receives the ACK for segment 3, then it will continue to send another segments.