2.2 · Lesson 3 of 5
Echo checks
Syllabus 2.2.3
What this lesson covers
- Describe checksums and echo checks
Key vocabulary
- Echo check
- The receiver sends the data back so the sender can compare it with the original.
- Original data
- The copy of the data the sender keeps, to compare with the echo.
- Returned data
- The copy the receiver sends back to the sender: the echo.
- Retransmission
- Sending the data again after an error has been detected.
- Limitation
- Data travels twice, and the sender can't tell whether an error happened on the way there or on the way back.
Check your learning
- Quick check: 4 questions
- Key vocabulary test: 5 terms
- Activity 1: Echo scenarios · 8 questions
- Activity 2: Echo checks quiz · 8 questions
- Activity 3: How an echo check works · drag and drop