loopback test

A test of a local loop initiated by a local exchange carrier (LEC) at the network edge

and causing a contact closure at the network interface unit (NIU) on the customer premises. The loopback test thereby allows the testing of the local loop in the forward direction, through the NIU, and loop-ing in the backward direction, all in isolation from the customer premises equipment (CPE) and wiring.

See also CPE, LEC, local loop, and NIU.

• Hertz, Heinrich Rudolf (1857–1894)
• Hertz (Hz)
• Hexadecimal
• hexadecimal notation (hex)
• hexadecimal notation (hex)
• hex (hexadecimal notation)
• HFC (Hybrid Fiber/Coax)
• HF (High Frequency)
• HF (High Frequency)
• high bit-rate digital subscriber line (HDSL)
• high capacity voice (HCV)
• high-cost area
• high definition television (HDTV)
• high density bipolar order 3 (HDB3)
• high frequency (HF)
• High-Level Data Link Control (HDLC)
• high-order mode
• high-pass filter
• High Performance Parallel Interface (HIPPI)
• high speed
• high-speed channel (H channel)
• High-Speed Circuit Switched Data (HSCSD)
• High Speed Downlink Packet Access (HSDPA)
• High Speed Uplink Packet Access (HSUPA)
• high-tier