In this illustration, we see a computer representing the sender and one representing the receiver positioned side-by-side. Beneath each one is a dotted line extending vertically downward, representing the passage of time. The operation is depicted here not as a blue arrow extending from one timeline to the other, but as a blue line representing the first bit of the first packet and a second blue line representing the last bit of the first packet, with light blue shading in between forming a band that extends from one side to the other.

The operation begins at the topmost point on the sender's timeline, labeled here as "First bit of first packet transmitted, t=0." Just below this is the second blue line, labeled "Last bit of first packet transmitted, t=L/R." These two lines form a band that extends diagonally downward to the right, towards the receiver's timeline. Where the first blue line intersects with the receiver's timeline, that point is labeled "First bit of first packet arrives." Where the second blue line intersects, that point is labeled "Last bit of first packet arrives, send ACK." Only the second blue line extends back diagonally downward to the sender's timeline, and the area of the timeline between these two lines is labeled "RTT." The point where the second blue line intersects with the sender's timeline is labeled "ACK arrives, send next packet, t=RTT + L/R." The next packet is sent.