A cost that varies in direct proportion to changes in volume, but which is uniform for each unit.

The difference between a pre-established measure and an actual measure.

A temporary communications link through an internetwork that appears to be a dedicated circuit between two network devices.

A service that allows a subscriber to receive messages via a voice mailbox system when an unanswered call is received on their phone or cell phone.

Voice over Internet Protocol allows voice calls to be encoded and transmitted over the data network. Benefits are cost-savings, the ease of managing just one network, and lots of new services ...

A network that uses public wires to connect nodes, often using the Internet to exchange data. These networks maintain t heir privacy for authorized users by employing encryption and other security ...