Above is an excerpt from a TCP $($Reno version$)$ transmission. What will the sequence number, acknowledgement number and payload length denoted S$1,$ A$1,$ P$1,$ S$2,$ A$2$ and

P$2$ be in the segments shown in the figure?

$S1=$ skrivinn svaret... $A1,P1=$

$S2=,A2=,P2$

The third segment is lost somewhere in the network on its route to the server. How does TCP ensure that this segment is delivered as shown in the excerpt above?

TCP also have a re$-$transmission timer. What happens when this timer expire