Interface functionality allows a telephone operator to perform advanced functions, such as switching on a telephone or Internet network, without going through the carrier. The operator can use a variety of equipment, including components not supplied by the carrier, for these functions. In some nations, the law requires that carriers who choose to offer enhanced features enable their networks to allow people to perform similar functions without having to go through the carrier. This allows customers more control over their telecommunications services.
A variety of interfaces are available for operators in facilities like corporations who need to be able to perform activities like three way calling, routing calls to voicemail, and so forth. Operators can place, receive, and terminate calls in exactly the same way the carrier does, using their own interface. In some cases this is provided by the carrier, which can install the necessary infrastructure for a fee. In others, companies may install their own, provided by a third party. The complexity of the equipment can vary, depending on the interface functionality the operator needs.
Many carriers provide a variety of enhanced services to their customers, some of whom may prefer to handle these on their own. Telecommunications customers need to be able to use the phone company's network for these enhanced functions, and thus the utility must enable what is known as comparably efficient interconnection (CEI). This provides access to the network and the ability to use third party interfaces and other systems with the network. The operator needs interface functionality to control a phone system and access the necessary features.
The operator can use the interface for a task like signaling or switching. Some interfaces are mechanical while others are electronic. Voice over Internet protocol (VoiP) technology, for example, relies on interface functionality to allow people to place calls through their computers over an Internet network. The available features can depend on the program but may include options like call forwarding and blocking.
Telecommunications standards establish basic guidelines for interface functionality to ensure cross-compatibility between various utilities and products. This provides more freedom for consumers and can also streamline such systems, as utilities can communicate easily with each other. Consumers, in turn, can use standardized equipment to connect with any utility's systems. Interface functionality is part of these standards, allowing people to perform a variety of enhanced functions on a phone network with their own equipment and controls.