Loopback
lastmod 2020-07-22created 2020-07-221 edits
Loopback (loop-back) refers to the routing of electrical signals, digital data streams, or flows of items back to their originating device or facility without intentional processing or modification. It is primarily used as a means of testing transmission or transportation infrastructure.
Example applications
- A communication channel with only one endpoint. Any message transmitted on such a channel is immediately received only from that same channel.
- When performing transmission tests of an access line from the serving switching center, no personnel are required at the served terminal.
- Connection testing between stations (not necessarily adjacent) where two lines are used. Involves testing at one station and on two lines interconnected at a distant station. Usually called loop around when the interconnected circuits are accessed by dialing.
- A patch cable that facilitates loop-back testing.