A call state in which the network transmits the caller's emergency service ID (CESID) to the public service answering point (PSAP) customer installation (CI). [T1.414-1998]

Synonym direct outward dialing.

The qualitative level at which a network fulfills its function. [After T
1. Rpt24-1993]

An ISDN number, supplied by the calling user's or the redirecting user's network, which is associated with the calling user or the redirecting user. It is possible that the NPN may have the same value as the user provided number (UPN) especially in cases where delivery of two calling party numbers is supported. The NPN may also be accompanied by… (Read More →)

1. The organization that maintains and operates the network components required for intelligent network (IN) functionality. A network provider may also take more than one role, e.g., also acting as service provider.
2. The entity connecting customers and Service Providers. The delivery system usually is composed of access networks and core or backbone networks, using a variety of network technologies.… (Read More →)

See network survivability.

Automatic or manual methods to return a network to its normal function in response to a network failure. [T
1. Rpt24-1993]

The network components that provide a virtual connection between two circuit sections. A network section may be either an access network section or a transit network section. [T1.504-1989]

Protection of networks and their services from unauthorized modification, destruction, or disclosure. It provides assurance the network performs its critical functions correctly and there are no harmful side-effects. [INFOSEC-99]

[A] subset of network architecture specifically addressing security-relevant issues. [INFOSEC-99]