In telecommunications, loopback devices perform transmission tests of access lines from the serving switching center, which usually does not require the assistance of personnel at the served terminal. Any message transmitted by such a channel is immediately and only received by that same channel.
It may be a communication channel with only one communication endpoint.
It is primarily a means of testing the communications infrastructure. Loopback (also written loop-back) is the routing of electronic signals or digital data streams back to their source without intentional processing or modification. Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. This article needs additional citations for verification.
