Asterisk: The Definitive Guide, 4th Edition

Chapter 13. Automatic Call Distribution (ACD) Queues

An Englishman, even if he is alone, forms an orderly queue of one.

—George Mikes

Automatic Call Distribution (ACD), or call queuing, provides a way for a PBX to queue up incoming calls from a group of users: it aggregates multiple calls into a holding pattern, assigns each call a rank, and determines the order in which that call should be delivered to an available agent (typically, first in first out). When an agent becomes available, the highest-ranked caller in the queue is delivered to that agent, and everyone else moves up a rank.

If you have ever called an organization and heard “all of our representatives are busy,” you have experienced ACD. The advantage of ACD to the callers is that they don’t have to keep dialing back in an attempt to reach someone, and the advantages to the organizations are that they are able to better serve their customers and to temporarily handle situations where there are more callers than there are agents.^[134]

Note

There are two types of call centers: inbound and outbound. ACD refers to the technology that handles inbound call centers, whereas the term Dialer (or Predictive Dialer) refers to the technology that handles outbound call centers. In this book we will primarily focus on inbound calling.

We’ve all been frustrated by poorly designed and managed queues: enduring hold music from a radio that isn’t in tune, mind-numbing wait times, and pointless messages that tell you every 20 seconds how important ...