jabber - An error condition caused by an Ethernet device transmitting longer frames than allowed or continuous random data.

jack - A common term for telecommunications outlet/connector. See also modular jack.

jack contact - The current-carrying metallic member in a modular jack. (TIA)

jacket - The outer layer of a cable. See also cable sheath.

jack header - A raceway similar to a header duct, usually provided in short lengths to connect a quantity of distribution ducts together. (TIA)

jackstand - A device for holding a large cable reel off the floor so the cable can be removed from the reel.

J-hook - A supporting device for horizontal cables that is shaped like a J. It is attached to some building structures. Horizontal cables are laid in the opening formed by the J to provide support for the cables.

jitter - Signal phase distortion in the time domain.

job plan - A comprehensive outline of all aspects of the project. It includes all work, material, and labor operations and scheduling, how and when the work is to be performed, how each aspect of the work will affect the remaining areas, and how the work will fit into the general contractor's construction schedule.

job site - The physical location where work is to be performed.

joint-owned pole - An outside plant pole owned by two entities.

joint random buried plant - Power, cables, and telephone cables that are placed in a common trench with little or no separation.

joint trench - A trench that contains the facilities of two or more companies.

joint use - The practice of two or more service providers (SPs) sharing the same facilities. In the case of utility poles, individual poles are typically owned by one SP, which in turn leases space to the other providers. In the United States, the CommunicationsAct of 1996 and some states' public utility commissions regulate this practice to ensure that public utility companies offer nondiscriminatory access to all other SPs.

joint-use pale - See joint use

jumper - 1. An assembly of twisted-pairs without connectors, used to join telecommunications circuits/links at the crossconnect. (TIA) 2. An optical fiber cable with connectors installed on both ends. See also cable assembly and pigtail.

jumper wire - Typically, 24 AWG [0.51 mm (0.020 in)] twisted-pair wire terminated on 66-blocks, 110-blocks, or screw terminals to join telecommunications feeder and distribution facilities at the cross-connect. See also jumper,

junction box - A location in the pathway system that allows transition of pathways and access to cables. (TIA)