In computer telephony an automatic dialler (shortened to an auto-dialler or more simply in context just a dialler, and also known as an outbound dialler) is a computer system that makes outgoing calls from a call centre to customers from call agents based upon a loaded list of contacts.[1][2] Whereas automatic call distribution (ACD) distributes inbound calls to a call centre amongst its agents, an auto dialler makes outbound calls and comes in several forms.[2] Auto diallers are responsible for providing management information to call centre operators, including how many outbound calls each agent has handled.[3] In more sophisticated computer telephony systems, a single system handles both ACD of inbound calls and dialling of outbound calls, allowing agents to be switched between the two as traffic volumes require.[3]
In their earlier forms, diallers would be proprietary standalone systems that connected directly to a private branch exchange or even to the public switched telephone network.[4] However, with the advent of customer-owned switching equipment providing call-control interfaces, diallers shrunk to being external adjunct systems that controlled existing switches.[4]