Common practice CSUs are required by PSTN providers at digital interfaces that terminate in a DSU on the customer side. They are not used when the service terminates in a modem, such as the DSL family of service. The maintenance capabilities of the CSU provide important guidance as to whether the provider needs to dispatch a repairman to the customer location.
Common practice CSUs are required by PSTN providers at digital interfaces that terminate in a DSU on the customer side. They are not used when the service terminates in a mode:m, such as the DSL family of service. The maintenance capabilities of the CSU provide important guidance as to whether the provider needs to dispatch a repairman to the customer location.