Technical Terms and Definitions

ACD - Hardware

In telephony, an Automatic Call Distributor (ACD), also known as Automated Call Distribution, is a device or system that distributes incoming calls to a specific group of terminals that agents use. It is often part of a computer telephony integration (CTI) system.

Routing incoming calls is the task of the ACD system. ACD systems are often found in offices that handle large volumes of incoming phone calls from callers who have no need to talk to a specific person but who require assistance from any of multiple persons (e.g., customer service representatives) at the earliest opportunity.

The system consists of hardware for the terminals and switches, phonelines, and software for the routing strategy. The routing strategy is a rule-based set of instructions that tells the ACD how calls are handled inside the system. Typically this is an algorithm that determines the best available employee or employees to respond to a given incoming call. To help make this match, additional data are solicited and reviewed to find out why the customer is calling. Sometimes the caller's caller ID or ANI is used; more often a simple Interactive voice response is used to ascertain the reason for the call.

Originally, the ACD function was internal to the Private Branch Exchange of the company. However, the closed nature of these systems limited their flexibility. A system was then designed to enable common computing devices, such as server PCs, to make routing decisions. For this, generally the PBX would issue information about incoming calls to this external system and receive a direction of the call in response.