Automatic Call Distributor

What Does Automatic Call Distributor Mean?

An automatic call distributor (ACD) in telephony is a system that distributes incoming calls to a specific group of terminals used by agents. It is a part of a computer telephony integration (CTI) system. ACDs recognize, answer and route incoming calls. They range from small systems maintaining a few lines up to systems maintaining a large number of lines for large applications.


An ACD system handles incoming calls based on the numbers called and an associated database of handling instructions. Companies that offer sales and service support use automatic call distributors to validate callers, make outgoing calls, forward calls to the right parties, permit callers to record messages, gather usage statistics, balance the use of phone lines and provide various other services.

Techopedia Explains Automatic Call Distributor

ACDs provide caller identification such as that provided by dialed number identification service (DNIS), direct inward dialing, etc. They process high volume incoming calls and distribute them to single or group extensions. They also distribute calls equitably to extensions called as agent lines. They permit only a limited number of staff members to effectively handle large numbers of calls, while assuming that someone is always available at the receiver side to handle calls. An ACD system also maintains records of the peak calling hours, the number of incomplete calls and the incoming call volume.

ACD systems are extensively used in offices handling large volumes of incoming phone calls from callers who require assistance. The routing strategy is a rule-based set of instructions, which tells the ACD how calls are handled in the system. This is the algorithm determining the most appropriate employees available to respond to the incoming calls. Additional data is also reviewed to determine the reason for each call, ascertained by a simple interactive voice response (IVR) system. Initially, the ACD function was internal to the private branch exchange of companies.

The system is designed to enable common computing devices. Additional functions for external routing applications include computer-telephony integration, which can improve call center agent efficiency by matching incoming calls with important data on a PC. This is achieved through the Computer-Supported Telephony Applications (CSTA) protocol.


Related Terms

Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.