Channel service unit

Telecommunications equipment

In telecommunications, a channel service unit (CSU) is a line bridging device for use with T-carrier, whichis used to perform loopback testing; may perform bit stuffing; may also provide a framing and formatting pattern compatible with the 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 central office, before the regenerated signal reaches a multiplexer or data terminal equipment (DTE).

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