### TCP sequence and ACK numbers with segment loss

Consider the figure below in which a TCP sender and receiver communicate over a connection in which the sender->receiver segments may be lost. The TCP sender sends an initial window of 4 segments. Suppose the initial value of the sender->receiver sequence number is 126 and the first 4 segments *each* contain 855 bytes. The delay between the sender and receiver is 7 time units, and so the first segment arrives at the receiver at t=8. As shown in the figure below, 0 of the 4 segment(s) are lost between the segment and receiver.

### Question List

1. Give the sequence numbers associated with each of the 4 segments sent by the sender. Format your answer as: a,b,c,...

2. Give the ACK numbers the receiver sends in response to each of the segments. If a segment never arrives use 'x' to denote it, and format your answer as: a,b,c,...

### Solution

1. The sender's sequence numbers are: 126,981,1836,2691

2. The receiver's ACKs are: 981,1836,2691,3546

That's incorrect

That's correct

The answer was: 126,981,1836,2691

The answer was: 981,1836,2691,3546