The ratio of the disturbing longitudinal source voltage, Vs, and the resultant metallic voltage, Vm, at the same frequency of the network under test, expressed in dB. The degree of balance between each conductor of a wire pair or equipment unit and ground is a measure of immunity to noise induced from external sources. [After T
1. Rpt16-1992]

Synonym gap loss.

A system of error control based on the formation of a block check following preset rules.
Note 1: The block check formation rules are applied in the same manner to each character.
Note 2: A combination of longitudinal and vertical redundancy check allows the detection and correction of single bit errors. Synonym horizontal redundancy check.

A voltage induced or appearing along the length of a transmission medium.
Note 1: Longitudinal voltage may be effectively eliminated by using differential amplifiers or receivers that respond only to voltage differences, e.g., those between the wires that constitute a pair.
Note 2: Induced longitudinal voltages at low (power-line) frequencies can be greatly reduced by twisting parallel wires to create… (Read More →)

Information concerning network resources available to support higher precedence calls.
Note 1: Available resources include idle circuits and circuits used for lower precedence calls.
Note 2: LFB information may be used to make call-path reservations.

1. A communications channel from a switching center or an individual message distribution point to the user terminal. Synonym subscriber line.
2. A pair of wires, or its equivalent, between a customer's station and the central office from which the station is served. [47 CFR Pt.36-A] Synonyms local loop, user line.
3. Go-and-return conductors of an electric circuit; a closed… (Read More →)

Synonym echo check.

A condition in which the network presents a low-resistance tip-to-ring dc path at the network interface (NI). [T1.407-1990]

The loss that could be provided by a digital loop carrier system or a fiber-in-the-loop system when a short customer analog access cable results in below-average attenuation. [T1.508-1998]

In a phase-locked loop, a filter located between the phase detector (or time discriminator) and the voltage controlled oscillator (or phase shifter).