channel service unit/data service unit definition communications, hardware
(CSU/DSU, or "..digital..") A device that performs both the channel service unit
(CSU) and data service unit
(DSU) functions. The Channel Service Unit (CSU) is used to terminate a DS1
(56/64 kb/s) digital circuit. It peforms line conditioning
, protection, loop-back
and timing functions. The Data Service Unit (DSU) terminates the data circuit to the Data Terminal Equipment
(DTE) and converts the customer's data stream into a bi-polar format for transmission.