In an information-transfer transaction, the phase during which user information blocks are transferred from the source user to a destination user.

A coordinated sequence of user and telecommunications system actions that cause information present at a source user to become present at a destination user.
Note: An information-transfer transaction usually consists of three consecutive phases called the access phase, the information-transfer phase, and the disengagement phase.

Acronym for information systems security.

The region of the electromagnetic spectrum bounded by the long-wavelength extreme of the visible spectrum (approximately
0. 7 m) and the shortest microwaves (approximately
0. 1 mm). See electromagnetic spectrum.

Preemptive or reactive risk-management techniques designed to increase confidence that disruption of a system will be minimized if its critical infrastructure is attacked.

Preemptive or reactive risk-management techniques designed to prevent disruption of a system after its critical infrastructure is attacked.

A signal that prevents the occurrence of an event.
Note: An inhibiting signal may be used, for example, to disable an AND gate, thus preventing any signals from passing through it as long as the inhibiting signal is present. [From Weik '89]

A procedure used to qualify a signaling link for carriage of signaling traffic, either for the first time or after failure has occurred. [T1.226-1992]

An initial block or “footprint” block is the first NXX-X block that a service provider receives in a rate center where the SP has no other assigned resources (FCC 00-104, ¶ 86 and 191).

The first geographic NXX code assigned to a Service Provider for each rate center in which it provides service.