Lucent Technologies DEFINITY Enterprise Communications Server Release 8 Guide To ACD Call Centers

							Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-1 Introduction 
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DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
1
Automatic Call Distribution (ACD) 
Basics — Overview and Exercises
NOTE:
This chapter provides knowledge that is prerequisite to attending an Instructor-led 
Training (ILT) course. 
Introduction
This chapter gives an overview of the Automatic Call Distribution (ACD) feature. It 
describes basic ACD capabilities for the following Lucent Technologies switches: 
nDEFINITY Enterprise Communications Server
nDEFINITY Communications System Generic 3.
This chapter addresses ACD terminology, switches and switch features, split queues, 
distributing and handling calls, ACD measurement, ACD capacities, and engineering 
guidelines.
nACD terminology define common terms that are used throughout this book.
nThe Switches and Switch Features section defines switches and ACDs and 
explains how the following features work: trunks, trunk groups, and extensions; 
automatic-in processing; switch attendant; and Direct Inward Dialing (DID) 
processing.
nSplit Queues defines a split queue and explains how to set up call processing to a 
split, including announcements for calls in a split queue; answer supervision and 
abandoned calls, intraflow and interflow, and night service for the ECS and 
Generic 3.
nDistributing and Handling Calls describes how calls are distributed to agents and 
how agents handle the calls. It also defines the split supervisor voice terminal 
buttons. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
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Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-2 ACD Terminology 
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nACD Measurement describes how CentreVu CMS collects measured data on 
splits/skills, extensions, trunks, trunk groups, VDNs, and vectors. This section also 
includes switch features that affect CMS data, such as Hold, Conference, Transfer, 
Multiple Call Handling, and so forth.
nACD Capacities contains capacity tables for DEFINITY ECS, Generic 3 switches, 
and CentreVu CMS. It also discusses measured extensions and multiple splits on a 
non-EAS switch and measured and unmeasured trunks.
nEngineering Guidelines presents ACD agent and trunk engineering guidelines for 
determining the number of agents and trunks required for an ACD. It contains 
examples and tables of average service times.
Exercises to Test Your Knowledge of ACD
At the end of the chapter are a series of exercises that you can use to demonstrate your 
knowledge of the information presented in this chapter.
In most cases you should be able to complete this chapter and the associated exercises in 
one hour. 
All of the exercises that you need to complete to be ready for the Instructor-led Training 
are found in this chapter. Prior to completing the exercises, you should read the chapter, as 
it introduces the concepts and skills associated with the ACD, and provides instruction on 
their application. 
It is important that you attempt to complete each Exercise. Even if you make mistakes, 
when you check your answers you’ll see how you should have responded and better 
understand the concept presented.
ACD Terminology
The following terms will provide general familiarity with the ACD environment.
Agent An agent is a person assigned to one or more splits/skills and 
handles calls to/from an extension in those splits/skills.
Agent In Multiple 
Splits/SkillsDepending on the ACD software, an agent can be a member of 
multiple splits/skills.
Agent State Agent state is a term or code that represents the current 
availability status of an agent. The term agent state also 
represents a user ability to change an agents availability within the 
system. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-3 ACD Terminology 
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Call Distribution 
MethodsThe ACD can distribute calls to agents in a split/skill in one of four 
ways:
— Circular Hunting (Generic 2 only)
— Direct (linear) Hunting
— EAD (Expert Agent Distribution)
— UCD (Uniform Call Distribution) and EUCD (Enhanced Uniform 
Call Distribution) or MIA
CMS Call Management System.
CMS is an adjunct (basic software package or optional enhanced 
software package) that collects call data from a switch resident 
ACD. CMS provides call management performance recording and 
reporting. It can also be used to perform some ACD 
administration. CMS allows users to determine how well their 
customers are being served and how efficient their call 
management operation is.
EAS Expert Agent Selection.
An optional feature available with Generic 3 and Generic 2.2 that 
uses Call Vectoring and ACD in the switch to route incoming calls 
to the correct agent on the first try based on skills.
Hunt Groups A group of trunks/agents selected to work together to provide 
specific routing of special purpose calls.
Queues (split/skill 
and/or attendant)If calls cannot be answered immediately, they are routed to a call 
collection point (split/skill queue or attendant queue) where calls 
are held until a split/skill agent or attendant can answer them. 
Calls are ordered as they arrive and they are served in that order. 
Depending on the time delay in answering the call, 
announcements, music, or prepared messages may be employed 
until the call is answered.
Skill An ability given to an agent to meet a specific customer 
requirement or a call center business requirement.
Split A group of extensions/agents that can receive standard calls 
and/or special purpose calls from one or more trunk groups.
Trunk Group A group of similarly administered trunks carrying calls to the 
switch. An ACD has its own pre-assigned trunk groups.
Trunk state A term or code that represents the current status of a particular 
trunk. 
Announcements An announcement is a pre-recorded message delivered to a caller 
in queue requesting the caller to remain on-line, prompting the 
caller for information or directing the caller to another destination. 
When a call is in queue, depending on the length of time in queue, 
an automatic recording can encourage the caller to hang on, call 
back later, call another number, leave a message or can be used 
with call prompting to direct the caller to specific destinations. 
These announcements can be scheduled to occur periodically. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
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Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-4 ACD Terminology 
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Call  Prompting Call Prompting is a call management method that uses specialized 
call vector commands to provide flexible handling of incoming calls 
based on information collected from the caller. One example 
would be where the caller receives an announcement and is then 
prompted to select (via dialed number selection) a department or 
an option that was listed in the announcement.
Call Vectoring Call Vectoring is an optional software package that allows 
processing of incoming calls according to a programmed set of 
commands. Call Vectoring provides a flexible service allowing 
direct calls to specific and/or unique call treatments.
Intraflow Intraflow is used when a splits/skills queue is heavily loaded or 
when a call arrives after normal work hours. Intraflow involves 
redirecting a call to a destination within the local switch network 
(the same switch system).
Interflow Interflow is used when a splits/skills queue is heavily loaded or 
when a call arrives after normal work hours. 
Interflow redirects a call to a destination outside the local switch 
network (a different switch system).
LAI Look Ahead Interflow.
LAI allows users to balance the call work load between multiple 
call centers on separate switching systems. LAI uses ISDN to 
allow multiple switches to communicate and interflow when 
appropriate.
MCT Malicious Call Trace.
MCT allows an agent to notify a predefined party a malicious caller 
is on the line. It also involves enabling a recording device to record 
the call.
Night Service Night Service is used when a call arrives after normal work hours. 
The call can be redirected to another destination such as another 
split/skill, an extension, the attendant, an announcement with 
forced disconnect, or a message center. Night Service can take 
one of three forms:
— Hunt Group (Split/Skill) Night Service
— Trunk Group Night Service
— System Night Service
Priority Queue The priority queue is a segment of a splits/skills queue from which 
calls are taken first.
Service Observing Service observing is a feature used to train new agents and 
observe in-progress calls. The observer (split/skill supervisor) can 
toggle between a listen-only mode or a listen/talk mode during 
calls in progress.
Split/Skill 
AdministrationSplit/Skill administration is the ability to assign, monitor, or move 
agents to specific splits/skills. It also involves changing reporting 
parameters within the system. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-5 ACD Terminology 
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Split/Skill Supervisor A split/skill supervisor is assigned to monitor/manage each 
split/skill and split/skill queue to accomplish specific split/skill 
objectives. A supervisor can assist agents on ACD calls, be 
involved in agent training, and control call intra/interflow.
Threshold A threshold is a point in time or criteria that determines a certain 
action by the system. For example, the number of calls in queue or 
the time calls spend in queue determines specific call treatments, 
or you can set the number of rings prior to announcements or call 
answers.
Call Center A call center provides a centralized location where a group of 
agents or company representatives communicate with customers 
via incoming or outgoing calls.
CAS Centralized Attendant Service.
CAS is a system feature used when more than one switch is 
employed. CAS is an attendant or group of attendants that 
handles the calls for all switches in that particular network.
DID Direct Inward Dialing.
DID is a process involving calls coming into the switch from the 
CO. The switch than routes the calls directly to the appropriate 
extension (as identified by the last four digits).
DNIS Dialed Number Identification Service.
DNIS is a feature of the 800 number service that sends the dialed 
digits to the called destination. This can be used with a display 
voice terminal to indicate the type of call to an agent. For example, 
the call by its destination can be classified as a certain type of call 
or caller (e.g., a Gold Card caller) depending on a product or 
service the destination number is associated with.
Extensions Voice terminals connected to a PBX/switch via telephone lines are 
referred as extensions. Extensions is also the term used to define 
the 3, 4, or 5 digit numbers used to identify the voice terminal to 
the PBX/switch software for call routing purposes.
Leave Word Calling Leave Word Calling is a system feature that allows messages to 
be stored for any ACD split/skill and allows for retrieval by a 
covering user of that split/skill or a system wide message retriever.
QDN Queue Directory Number.
QDN is an associated extension number of a split. It is not 
normally dialed to reach a split. The split can be accessed by 
dialing the QDN. The QDN is also referred to as a split group 
extension.
Trunk/Trunk Group Trunks are communication channels between two switching 
systems or offices. Trunks grouped together to provide identical 
communications characteristics are called trunk groups. Trunks 
within trunk groups can be used interchangeably between two 
communications systems or central offices in order to provide 
multi-access capability. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-6 Switches and Switch Features 
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Switches and Switch Features
This section defines switches and ACDs and explains how they work. The section 
contains the following topics:
nTrunks, trunk groups, and extensions
nAutomatic-in processing definition
nThe attendant
nSwitch with attendant and extensions
nDirect Inward Dialing processing with an example
nAutomatic-in processing of ACD calls
nDID processing of ACD calls
nCall processing on an ACD switch.
What a Switch Does
A switch is an electronic device that processes incoming, outgoing, and internal calls and 
connects them to the proper destinations. The telephone company switch in your local area 
is called a Central Office (CO). A switch owned by a company or organization processes 
incoming, outgoing, and internal calls. Throughout this chapter, the term switch is used to 
refer to a company or organization’s switch.
Trunks, Trunk Groups, and Extensions
Incoming calls to a company first pass through the CO. The CO sends calls to the 
company switch over trunks (telephone lines that carry calls between two switches, 
between a CO and a switch, or between a CO and a phone).
The CO receives dialed digits from the caller, processes the digits, and seizes a trunk that 
is assigned those digits. After the CO seizes a trunk, it sends a continuing transmission to 
the destination phone or switch, and no other calls can be sent over that trunk until the 
current call disconnects.
Since a trunk can carry only one call at a time, trunk groups are usually created. A trunk 
group is a group of trunks that are assigned to the same digits. With a trunk group, the CO 
receives the digits of a dialed phone number and checks the trunk group assigned to that 
number to see if any of the trunks are available. The CO then seizes an available trunk. As 
many simultaneous calls can be made over a trunk group as there are trunks in that trunk 
group. A trunk group, therefore, can carry multiple calls for the same phone number. 
When a trunk group carries incoming calls (that is, calls made outside the company’s 
switch location) to the switch, the switch then connects the calls to their proper 
destinations within the company. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-7 Switches and Switch Features 
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The switches previously listed, in addition to connecting incoming calls to the proper 
destinations, are also like private COs for company employees. That is, employee phones 
are connected to a switch by telephone lines called extensions. Extensions are then 
assigned 3- 4- or 5-digit numbers within the switch software, and these numbers become 
the employee phone numbers for internal (intra-company) calls.
Automatic-In Processing
Automatic-in processing is one type of call processing. With automatic-in processing, the 
CO processes all of the digits of an incoming call. The CO then seizes a trunk from the 
trunk group, but since processing is complete, the call connects directly to a destination 
identified in the switch software. That destination can be a phone, a queue (in which 
callers wait to be answered in the order in which their call was received), or special 
treatment like an announcement.
Switch Attendant
Incoming calls can also go to a switch attendant. A switch attendant is a person who 
manually routes calls to their proper destinations using an attendant console (which is like 
a call switchboard). Normally an attendant serves as an internal operator who transfers 
calls to the proper extensions. Often, a switch will have more than one attendant, and all of 
the switch’s attendants will answer calls directed to the attendant queue, which holds calls 
until an attendant is available. The attendant queue receives internal calls made from 
employee extensions, and also receives incoming calls through DID processing and 
automatic-in processing. Attendant call handling varies, depending on the company’s 
needs. However, if the attendant has an automatic-in number, it will normally be the 
number published in the phone book, and the DID number will most likely be used by 
off-site employees who know only the attendant’s extension number. 
Centralized Attendant Service (CAS) is a switch feature that enables attendants to be 
consolidated at one private-network location. The attended location is called the CAS 
main and each unattended location is called a CAS branch. At branch locations, calls 
requiring attendant services route by way of Release Link Trunks to the main location.
Direct Inward Dialing Processing
With Direct Inward Dialing (DID) processing, incoming trunks do not connect the CO 
directly to an employee’s phone; instead, the incoming trunks are pooled by the switch, 
and this pool of trunks is then shared by employee phones. Extension numbers may serve 
as the final digits of employee phone numbers for incoming calls. That is the CO may 
assign a 2- 3- or 4- digit prefix to a trunk group. Then, when a 7-digit employee phone 
number is dialed, the call is processed as follows:
1. The CO processes the prefix of the dialed number, and then seizes a trunk in the 
trunk group that is assigned that prefix. 
2. The CO passes the remaining digits of the dialed number to the switch.
3. The switch recognizes the remaining digits as an employee extension number and 
sends the call to that extension. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-8 What the ACD Does 
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DID Processing Example
As an example of DID processing, say that Employee A has the external phone number 
538-1000 and the extension number 1000. Employee B has the phone number 538-9999 
and the extension number 9999. The steps in completing calls to Employees A and B 
might be as follows: 
1.Employee A’s client dials 538-1000.
2. The CO serving Employee A’s company identifies the digits 538 (the common 
prefix for all phone numbers to that company) and seizes Trunk 1 in the trunk 
group assigned the digits 538.
3. The CO passes the digits 1000 to the switch at Employee A’s company.
4. The switch identifies the digits 1000 as Employee A’s extension number and sends 
the call to Employee A’s extension. 
5. Employee A’s phone rings and Employee A answers. 
6. Meanwhile, Employee B’s client dials 538-9999. 
7. The CO identifies the digits 538 and seizes Trunk 2 in the trunk group assigned the 
digits 538. 
8. The CO passes the digits 9999 to the switch. 
9. The switch identifies the digits 9999 as Employee B’s extension number and sends 
the call to Employee B’s extension. 
10. Employee B’s phone rings and Employee B answers. 
While Employees A and B continue to talk, Trunks 1 and 2 in the 538 trunk group will not 
accept any more calls, so another call beginning with the digits 538 will seize yet another 
trunk in the trunk group.
What the ACD Does
Automatic Call Distribution (ACD) is a switch software feature that processes 
high-volume incoming, outgoing, and internal calls and distributes them to groups of 
extensions called hunt groups or splits. The switch also sends information about the 
operation of the ACD to the CentreVu CMS which stores and formats the data and 
produces real-time and historical reports on ACD activity. For more detailed information 
about ACD, read the feature description in the product documentation that came with your 
switch.
ACD is used by a call center to route incoming calls to specifically assigned splits/skills 
and agents. ACD allows a system administrator to create an efficient call management 
environment. This administrator can add or remove splits/skills from the system, add or 
remove announcements, add or remove agents, add trunk groups and route calls to the 
appropriate splits/skills. The administrator can also specify ACD measurement criteria 
and use an optional CMS package to provide reports on ACD efficiency. 
						

							DEFINITY ECS Release 8
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Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-9 Split Queues 
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Things to Know Before You Start
A voice response port or a person who answers ACD calls is called an agent. Companies 
that operate high-volume call-answering centers, for example, a catalogue sales center, a 
reservations center, or a customer service center, use the ACD feature to process incoming 
calls and distribute them to agents. In addition to agents, each ACD split can be assigned a 
split supervisor. The split supervisor uses various switch and CentreVu CMS features to 
monitor split and agent performance and to provide assistance if necessary. Maintaining 
trunks from the CO to the switch and hiring agents to answer calls costs money. However, 
if customers who call to purchase goods or services have difficulty reaching an agent and, 
therefore, stop trying to get through, the call center loses revenue. Call center management 
needs, therefore, to determine how many trunks and agents are necessary to minimize 
costs and maximize the ability of customers to purchase goods or services. Management 
can then set up and maintain the ACD accordingly. 
Automatic-In Processing of ACD Calls
Through switch administration, each automatic-in trunk group is assigned to an ACD 
split. All calls that come in on an automatic-in trunk group are directed to the assigned 
split. Then the ACD software distributes the calls to the agent extensions assigned to the 
split according to the assigned call distribution method (described later).
DID Processing of ACD Calls
Generic 3 enables you to dial directly to various extensions such as a VDN, a hunt group, 
an agent, or a login ID. Each extension can be assigned to a split as a DID extension.
For DID processing, trunk groups are not assigned to the split. The creation of associated 
extensions is sufficient to send calls arriving over DID trunk groups to the appropriate 
split. Each split can receive incoming calls through DID processing, automatic- in 
processing, or both. Automatic-in trunk groups carry calls only to the split, whereas DID 
trunk groups carry calls to any extension identified in the switch software, not just a split.
Split Queues
This section defines a split queue and explains how to up call processing to a split. The 
section contains the following topics:
nSplit queue call processing
nAnnouncements for calls in a split queue
nAnswer supervision and abandoned calls
nIntraflow and interflow
nNight service for the ECS and Generic 3. 
						

							DEFINITY ECS Release 8
Guide to ACD Call Centers  555-233-503  Issue 2
December 1999
Automatic Call Distribution (ACD) Basics — Overview and Exercises 
1-10 Split Queues 
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Split Queue Call Processing
A split queue is a holding area for calls waiting to be answered, usually in the order in 
which they were received. When a call is put into queue, the caller may hear one or more 
delay announcements, music, and/or silence, depending on the treatment assigned for the 
split. (Treatment of calls in queue is assigned through switch administration.)
Things to Know Before You Start
Calls enter the queue at the bottom and move toward the top or head of the queue. After a 
call reaches the head of the queue, it connects to the next available agent.
For the DEFINITY ECS and Generic 3 switches with the Call Vectoring feature, all call 
treatment including routing, queuing, announcements, and music is specified by call 
vectors. When a call arrives at a split, the ACD software checks to see if an agent is 
available to handle the call. If an agent is not available (that is, all agents are busy), the call 
enters the split’s queue.
For the DEFINITY ECS and Generic 3 switches, calls queue only if no agents are 
available, a queue is assigned to the split, and the queue is not full. If the queue is full, the 
caller hears a busy tone or the call goes to coverage. If the split is vector controlled, then 
this step will fail. Furthermore, if no agents are logged into the split or if all agents are in 
AUX work mode (described later), calls do not queue.
Priority and Normal Split Queues
Each split can have two queues: a normal queue and a priority queue. A split always has a 
normal queue and can also be assigned a priority queue. The ACD distributes all calls in 
the priority queue before it distributes any calls in the normal queue. Therefore, the 
priority queue, if one exists, must be empty before the ACD distributes calls in the normal 
queue.
For the DEFINITY ECS and Generic 3, priority queuing may be assigned in the Class of 
Restriction (COR) associated with the split extension number. A split may also be 
assigned Priority Queuing on Intraflow, which means that calls to that split, if rerouted to 
another local split, will enter the destination split’s priority queue.
Split Queue Size for ECS and Generic 3
Queue size is established through switch administration on the DEFINITY ECS Release 5 
and the Generic 3 switch. Calls arriving after the administered queue limit is reached 
receive a busy signal or go to the split’s busy coverage if administered. (If the split is 
vector controlled, then this step will fail.) Or, calls can be redirected to a local or remote 
destination. See the Intraflow and Interflow for more information.