Editing Channel service unit (section)

{{short description|Telecommunications equipment}}
{{no footnotes|date=January 2013}}

In [[telecommunications]], a '''channel service unit''' ('''CSU''') is a [[telephone line|line]] [[Bridging (networking)|bridging]] device for use with [[T-carrier]], which
*is used to perform [[loopback]] testing;
*may perform [[bit stuffing]];
*may also provide a [[framing (telecommunication)|framing]] and formatting pattern compatible with the [[telecommunications network|network]];
*provides a barrier for electrical interference from either side of the unit; and
*is the last signal regeneration point, on the loop side, coming from the [[telephone exchange|central office]], before the regenerated signal reaches a [[multiplexer]] or [[data terminal equipment]] (DTE).