Echo (computing)

For the computer command-line interpreter command named echo, see echo (command).

In telecommunications, echo is the local display of data, either initially as it is locally sourced and sent, or finally as a copy of it is received back from a remote destination. Local echo is where the local sending equipment displays the outgoing sent data. Remote echo is where the display is a return copy of data as received remotely.[1][2] Both are used together in a computed form of error detection to ensure that data received at the remote destination of a telecommunication are the same as data sent from the local source (a/k/a echoplex, echo check, or loop check). When (two) modems communicate in echoplex mode the remote modem echoes whatever it receives from the local modem.[3][4][5][6][7]

  1. ^ Graf 1999, p. 230.
  2. ^ Anmol 2000, p. 80.
  3. ^ Rosch 1999, p. 1161.
  4. ^ Weik 2000, "echo check" p. 478.
  5. ^ Weik 2000, "echoplex" p.479.
  6. ^ Jordan & Churchill 1987, p. 24.
  7. ^ Hill Associates 2002, p. 341.