In a telecommunications system, a demand by a user for a connection to another user.
Note: In telephone traffic analysis, call attempts are counted during a specific time frame. The call-attempt count includes all completed, overflowed, abandoned, and lost calls.

[The] procedure for identifying and authenticating a remote information-systems (IS) terminal, whereby the host system disconnects the terminal and reestablishes contact. [INFOSEC-99] Synonym dial back.

1. The contention that occurs when a terminal and data circuit-terminating equipment (DCE) specify the same channel at the same time to transfer a call request and handle an incoming call.
Note: When call collision occurs, the DCE proceeds with the call request and cancels the incoming call.
2. The condition that occurs when a trunk or channel is seized… (Read More →)

The ratio of successfully completed calls to the total number of attempted calls.
Note: This ratio is typically expressed as either a percentage or a decimal fraction.

One of a set of control characters used in call-control signaling.
Note: The signals representing call control characters may be used under defined conditions on interchange circuits other than the originating circuit.

The network intelligence that provides call/connection processing and control. [T1.667-1999]

A member of the set of network management signals used to establish, maintain, or release a call.

The logical link between the device performing an electronic surveillance access function and the LEA (law enforcement agency) that primarily carries call-identifying information. [T1.260-1998]

1. The delay that occurs when a call arrives at an automatic switching device and no channel or facility is immediately available to process the call.
2. The time between the instant a system receives a call attempt and the instant of initiation of ringing at the call receiver end instrument.

A service feature in which call data on a specific telephone extension or group of subscribers are collected and recorded for cost-of-service accounting purposes.