The T1 CSU ACE is a compact, full-featured T1 channel service unit used to connect T1 data terminal equipment (DTE) and T1 facilities. The unit is designed to provide alarms, loopbacks, signal regeneration, line build out, and surge protection. The unit is suitable for wall mounting or desktop use. Five LEDs on the front of the unit (POWER, NET LOS, EQ LOS, NET LB, and EQ LB) display the status of the unit. On the back of the unit an eight position dip switch provides settings for customer premises equipment and network line build out (LBO) distances as well as manual loopback operation. The two network LBO switches provide four combination settings from 0 to 22.5dB in 7.5dB increments. The three switches allotted for the equipment LBO offer five combination settings for PBX termination at distances up to 655 feet. Two additional switches provide for manual loopback (LB) in both the Equipment (EQ) and Network (NET) directions. The last switch is a spare. The unit provides three bantam jack pairs for testing purposes. Two pairs provide interruptive transmit and receive access toward the T1 network or the Data Terminal Equipment (DTE) device. The third pair is a non-interruptive connection for monitoring data flowing in either direction. Two RJ-48C modular jacks provide the network and DTE connections. A 12 VDC wall mount power supply that plugs into a receptacle, is included with the unit. The T1 CSU ACE also supports a customer-supplied 48 VDC power source and enables wall mount applications via integrated keyholes in the base.