See available line.

Synonym occupancy.

Universal Serial Bus

Synonym available line.

The name of a set of computers and networks used for creating, forwarding, or displaying some computer conferences. [2382-pt.35]

1. A person, organization, or other entity (including a computer or computer system), that employs the services provided by a telecommunication system, or by an information processing system, for transfer of information.
Note: A user functions as a source or final destination of user information, or both. Synonym subscriber.
2. [Insecurity, a] person or process authorized access to an IS… (Read More →)

An entity that carries out specific functions on behalf of its owner or user. Such functions usually entail requesting some service or responding to a request for service. When requesting service, the User Agent acts as a User Agent Client (UAC), and when responding to a request for service, it acts like a User Agent Server (UAS). For example, a… (Read More →)

A communications channel allocated to the user for input of information such as data communication for use in maintenance activities and removing of alarms external to the span equipment in a proprietary fashion. [After T1.105-1988]

In the Internet Protocol suite, a standard, low-overhead, connectionless, host-to-host protocol that is used over packet-switched computer communications networks, and that allows an application program on one computer to send a datagram to an application program on another computer.
Note: The main difference between UDP and TCP is that UDP provides connectionless service, whereas TCP does not.

1. A character string or pattern that is used by a data processing system to identify a user. [2382-pt.8]
2. [A] unique symbol or character string used by an information system (IS) to identify a specific user. [INFOSEC-99] Synonym user identification.