Think it through together · A little story
A girl gives the robot notes numbered 1, 2, and 3, but her friend receives only 1 and 3. Who should notice the missing note?
Lay out the process
- SendThree parts of data
- ArriveOne middle part is missing
- Reliable transportDetects the gap and tries to resend
- Still failingThe connection may report an error
Data can be lost because of congestion, link problems, and other causes. How it is recovered depends on the protocol and application.
TCP provides a reliable, ordered byte stream using mechanisms such as sequence numbers, acknowledgments, and retransmission. UDP does not automatically replace lost data. An application can also design its own recovery method.
For real-time audio and video, it can sometimes be better to skip an outdated piece than to wait a long time for it.
Your turn to try
If a tiny piece of sound is missing from a video call, would it definitely be better to wait ten seconds for it to come back?
Have you thought it through? Open for an explanation
Not necessarily. Delayed sound may disrupt the conversation. Real-time apps are designed to balance timeliness and completeness according to their needs.
Take away one discovery
Data can be lost because of congestion, link problems, and other causes. How it is recovered depends on the protocol and application.
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.