Think it through together · A little story
A large picture will not fit into a small envelope, so the girl divides it into parts. Why can’t a network always treat a whole photo as one infinitely large packet?
Lay out the process
- Large imageMany bytes
- Divide into suitable piecesFit transmission limits
- Send in turnsShare the network
- Receive and processRecover the content
A network link can carry only a limited amount of data at a time, so large content is usually divided into pieces.
Smaller pieces let different communications take turns using the link. If one piece has a problem, it may be possible to resend only the relevant data instead of transferring the whole file again.
Application-layer chunks, transport-layer segments, and IP fragments are not exactly the same thing. For now, notice the general fact that large content can pass through multiple transmission units.
Your turn to try
If a photo doubles in size, will the number of packets exactly double too?
Have you thought it through? Open for an explanation
Not necessarily. Headers, piece sizes, and boundaries all have an effect. More data usually needs more transmission, but not necessarily an exact whole-number multiple.
Take away one discovery
A network link can carry only a limited amount of data at a time, so large content is usually divided into pieces.
Try covering the diagram above and explaining each step to someone in your family. If one step is hard to explain, go back and look at that card again.