{{Short description|Telecommunications device}} {{one source|date=July 2024}} {{Use dmy dates|date=July 2024}}
In telecommunications, a '''customer service unit''' (CSU) is a device that provides an accessing arrangement at a user location to either switched or point-to-point, data-conditioned circuits at a specifically established data signaling rate.
A CSU provides local loop equalization, transient protection, isolation, and central office loop-back testing capability.
==References== {{FS1037C}}
Category:Local loop
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