(also echo test, loopback check)
Echo check definition
An echo check is a way of testing the integrity of a communication link. In an echo check, a signal is sent from one communications endpoint to another, then back again. The returned data (the “echo”) is then compared with the original to see if there are any issues with the data transmission path (such as delays, errors, or packet loss).
How an echo check works
- The sending device sends a test signal through the communication channel to the receiving end (which is specifically configured to recognize the message as an echo test signal).
- Instead of discarding or processing this echo test signal as normal data, the receiving device immediately sends it back to the sender.
- The sending device receives the echo test signal and compares it with the original. If the data is identical, the data transmission was successful — there were no errors or data corruption in the process.
- If the received data differs from the one that was sent, there is an issue with the communication link. Further investigation is necessary to narrow down the problem, which can range from faulty hardware to network congestion.
- Once the issue has been identified, the operators of the communication channel take appropriate steps to fix it. Then, the echo check is performed again to see if there are any other problems that need to be addressed.