[An] item designed to secure or authenticate telecommunications.
Note: COMSEC material includes, but is not limited to, key, equipment, devices, documents, firmware or software that embodies or describes cryptographic logic and other items that perform COMSEC functions. [INFOSEC-99]

[A] removable component that performs COMSEC functions in a telecommunications equipment or system. [INFOSEC-99]

[The] act of listening to, copying, or recording transmissions of one's own official telecommunications to analyze the degree of security. [INFOSEC-99]

[A] statement of COMSEC measures and materials used to protect a given operation, system, or organization. [INFOSEC-99]

[An] organized collection of COMSEC and communications information relative to a given operation, system, or organization. [INFOSEC-99]

Information required by a COMSEC equipment or system to enable it to properly handle and control key. [INFOSEC-99]

Central office equipment whose function is to concentrate traffic from subscriber lines onto a lesser number of circuits between the remotely located concentration equipment and the serving central office concentration equipment. This concentration equipment is connected to the serving central office line equipment. [47 CFR Pt.36-A]

1. In data transmission, a functional unit that permits a common path to handle more data sources than there are channels currently available within the path.
Note: A concentrator usually provides communication capability between many low-speed, usually asynchronous channels and one or more high-speed, usually synchronous channels. Usually different speeds, codes, and protocols can be accommodated on the low-speed side.… (Read More →)

In an optical fiber, the distance between the center of the two concentric circles that specify the cladding diameter and the center of the two concentric circles that specify the core diameter.
Note: The concentricity error is used in conjunction with tolerance fields to specify or characterize optical fiber core and cladding geometry. Synonyms core eccentricity, core-to-cladding concentricity, core-to-cladding eccentricity,… (Read More →)

An off-hook condition applied to the network interface (NI) by the network that indicated the network intends to complete a call attempt to the customer installation (CI) or intends to continue an established connection. [T1.208-1989]