Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This application is a divisional of Canadian patent
application S. N. 2,024,881 filed on September 7/90.
Background of the Invention
The invention relates to automatic call distributing
systems for automatically distributing incoming telephone calls to
one of a plurality of agent stations.
An automatic call distributor (ACD) is a call management
system that efficiently routes calls, such as toll-free "800"
calls, to agents in telemarketing and service inquiry centers and
provides specialized real-time call management and report
generation capabilities. An ACD is a unique communications
product in that it directly supports the operation and management
of a customer's business. The ACD monitors the status of each
agent and, when an incoming call is received, selects the agent
best able to handle a particular marketing or service request.
The ACD also provides detailed reporting on the performance of the
agents in their tasks, reporting such statistics as the number of
calls handled and the time spent in various stages of call
handling.
There are generally two types of ACDs. The first type
employs customer premises switching hardware to make connection
between the incoming telephone calls and the agents handling the
calls. The switching hardware has associated with it substantial
initial cost and ongoing maintenance activities and expense.
Examples of the first type are systems that are commercially
available from Teknekron Infoswitch Corp., DFW Airport, TX and
Aspect TeleCommunications, San Jose, CA.
The second type of ACD is implemented as services
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provided by central office systems (e.g. Centrex ACD available
from N.Y. Telephone). These services provide greater freedom in
agent location and relief from
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hardware maintenance but at the cost of reduced
functionality and reduced customer control.
Summary of the Invention
In one aspect, the invention features in general
an automatic call distributing system for automatically
distributing telephone calls placed over a network to
agent stations connected to the network by network
service interfaces. The system includes a receiving
means that is connected to the network by a network
service interface and receives agent status messages and
a call arrival message from the network indicating that
an incoming call has been made on the network. It also
includes a routing means that is responsive to the
receiving means to generate a routing signal that is
provided to the network to connect the incoming call to
an agent station through the network. In this manner,
the automatic call distributing system has great
flexibility in locating agents, so long as they are
connected to the network, and in deciding which agent an
incoming call should be routed to. At the same time, the
system employs the switching hardware of the network to
actually perform the switching function, thereby avoiding
costs and maintenance associated with the switching
hardware. In addition, the system permits the system
operator to maintain control of routing and any data
associated with routing by the system operator. This
leads to flexibility in monitoring and reporting agent
activity for management purposes.
In preferred embodiments, the routing signal is
based on status signals received from the agent stations,
and can also be based on the characteristics of the agent
stations (e.g., capabilities, identities of agents at the
stations, or locations of the agent stations) or on the
characteristics of the incoming telephone call (e.g., the
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telephone number dialed, the dialing telephone number of
the incoming call or the geographic location of the
incoming call) so as to connect the incoming call to the
appropriate agent station. The routing signal causes the
network to establish a telephone connection from the
routing means to the agent station and to thereafter have
the network connect the incoming call and the telephone
connection to the agent station. The network can be a
public or private telephone network. The network service
interface is an integrated services digital network
interface, and the status messages are provided according
to the X.25 standard. The agent station can be
implemented by a personal computer or workstation or can
be implemented by a device having the dedicated function
of control of communication via the network service
interface. The agent stations have a plurality of agent
states associated with a sign-off condition in which the
agent stations do not transmit agent status messages to
the routing means and a plurality of states associated
with a sign-on condition during which the agent stations
do provide the agent status messages to the routing
means. The agent stations can initiate outgoing calls in
a sign-off condition. In the sign-on condition the agent
station can provide a call initiating signal to the
routing means, and the routing means thereafter selects a
destination telephone number for the agent station. The
agent station can include an automated agent or it can
include an interactive display terminal for interaction
with a human agent. An external host processor
containing information as to the business supported by
the automatic call distributing system is connected to
provide information to and to receive information from
the routing means and the agent stations. A system
manager station is connected toOreceive information as to
the operation of the automatic call distributing system
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from the routing means and to provide control signals to
the routing means, the control signals including signals
for programming the generation of the routing signal by
the routing means. An agent supervisor station is
S connected to receive agent performance information and to
provide control signals to the routing means, the control
signals relating to the support of the supervised agent
activities.
In another aspect, the invention features, in
general, an automatic call distributing system including
a plurality of agent stations and a call router device
for directing incoming telephone calls to the agent
stations. The agent stations have a plurality of agent
states associated with their operation and provide agent
state status messages including state transition
notifications and state transition requests, and are
responsive to forced response signals that force
transitions in agent states. The call router device
includes an agent station state manager that is connected
to receive the transition notifications and transition
requests from the agent stations and to provide forced
response signals to the agent stations.
In preferred embodiments, the agent stations
include means to wait for a forced response signal from
the state manager before changing state when a transition
request has been sent. The agent stations have an active
state in which the incoming calls are connected, a ready
state in which the agent station is ready to receive an
incoming call, and one or more other states in which the
agent station is not ready to receive an incoming call.
The use of transition requests and forced responses
avoids the possibility that an agent may initiate a
transition out of the ready state after the call router
device has assigned a call to it but prior to delivery of
the call. The agent stations also include a set-up state
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in which the agent station can initiate an outgoing
telephone call and an idle state. The agent station has
one or more input devices to initiate state transitions
and a programmable transition table determining which
transitions involve transition notifications, which
involve transition requests and which are errors. The
call router device has a programmable response table
indicating what forced response signals apply to what
transition requests.
In another aspect, the invention features in
general an automatic call distributing system in which a
call router device is able to programmably change the
availability of agent states at agent stations as a
function of the number of incoming calls placed to the
automatic call distributing system.
In other aspects, the invention features, in
general, enhanced procedures for automatically rerouting
an incoming call placed over a network. In one aspect an
incoming call notification signal is sent from a call
receiver device to a call destination device, and the
call destination device sends a response signal to the
call receiver device after receiving the notification
signal, thus providing ~ackward communication. In
another aspect, the call receiver device provides a pre-
notification signal indicating the nature of the incomingtelephone call prior to directing the incoming call to
the destination device. In another aspect, the call
receiver device receives a calling line identification
signal, and the calling line identification is used in
determining which of the plurality of destination devices
the incoming call should be sent to. In preferred
embodiments, the incoming call is not directed to the
destination device until answering of a call at the
destination device, and a tone is provided at the call
receiver device which is removed when the incoming call
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is connected to the destination device. The destination device
will not respond to incoming calls that have not been directed to
it by the call receiving device when in a signed-on condition. In
another aspect, the invention features in general, a system for
automatically establishing a communication connection over a
network between a service requesting station and one of a
plurality of agent service providing stations that are connected
to the network via network service interfaces and provide agent
status messages to the network. The system includes a receiving
means that is connected to the network by a network service
interface and receives agent status messages and a service request
message from the network indicating that an incoming service
request has been made by a service requesting station on the
network. The system also includes a routing means that is
responsive to the receiving means to generate a routing signal
that is provided to the network to connect the incoming service
request to an agent service providing station through the network.
In preferred embodiments, the routing signal is based on
the status signals to connect the incoming service request to the
appropriate agent service providing station; the network is a
public or private telephone or data network; there is
communication of voice, image or video signals.
In summary, a first broad aspect of the invention
provides an automatic call distributing system for automatically
distributing telephone calls placed over a telephone network to
one of a plurality of agent stations, said system comprising a
call router device for directing incoming telephone calls to agent
stations, a plurality of agent stations connected to communicate
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with said call router device, said agent stations having
autonomous state machines defined by a plurality of agent states
and state transitions that determine the operation of said agent
stations, said agent stations providing agent state status
messages to said call router, said agent state status messages
including transition notifications indicating transitions from one
state to another state that do not require approval from said call
router and transition requests indicating requests for transition
from one state to another state for transitions that do require
approval from said call router, ea~h said agent station being
responsive to a forced response signal which causes said state
machine to make a transition to one of its defined states, said
call router device including an agent station state manager
connected to receive said transition notifications and said
transition requests and to provide said forced response signals to
said agent stations.
A second broad aspect of the invention provides an
automatic call distributing system for automatically distributing
telephone calls placed over a telephone network to one of a
plurality of agent stations, said system comprising a call router
device for directing incoming telephone calls to agent stations,
and a plurality of agent stations connected to communicate with
said call router device, said agent stations having autonomous
state machine defined by a plurality of agent states and state
transi`tions that determine the operation of said agent stations
said agent stations providing agent state status messages to said
call router indicating said agent states, said call router device
including means for programmably changing said agent states and
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state transitions that define said autonomous state machines as a
function of the number of incoming calls placed to the automatic
call distributing system.
Other advantages and features of the invention will be
apparent from the following descriptions of embodiments thereof
and from the claims.
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Description of the Preferred Embodiment
Drawinqs
Figure 1 is a block diagram of a switchless automatic
call distributing system according to the invention.
Figure 2 is a diagram illustrating the handling of an
incoming call on the Figure 1 automatic call distributing
system.
Figure 3 is a diagram showing the software
architecture in the Figure 1 automatic call distributing system.
Figure 4 is a diagram of the agent states and
transitions for an agent station of the Figure 1 system.
Figure 5 is a diagram illustrating an example of the
protocol for transferring an incoming call to an agent station
on the Figure 1 system.
Figure 6 is a flow chart describing the method
employed by a call router of the Figure 1 system in selecting an
agent station to receive an incoming call.
Figures 7A & 7B are diagrams of agent states
illustrating modifying transitions between states.
Structure
Referring to Figure 1, there is shown automatic call
distributing (ACD) system 10 for distributing incoming calls,
e.g., from caller 12, to agent stations, e.g., stations 20, 22,
that are connected to public telephone network 14. Each of the
components of ACD system 10 is connected to public telephone
network 14 via a network service interface 16, which in the
preferred embodiment is an integrated systems digital network
(ISDN) interface, as is described in more detail below.
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Call router 18 is used to cause network 14 to connect
an incoming call from caller 12 to one of a large number of
agent stations. Call router 18 selects the
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agent station based upon information received from the
agent stations and other information. Call router 18
also assures that agent and system performance data is
collected as needed for management purposes. For
outgoing calls, call router 18 is involved as required by
the particular ACD application, e.g., to handle queuing
in agent-to-agent and agent-to-supervisor communication,
or in selecting destinations for telemarketing campaigns
or external consultation.
Two implementations for agent stations are shown
on Fig. 1: nonintegrated agent station 20 and integrated
agent station 22. The nonintegrated station has a
separate device 24 for controlling network connections
and handset 26 that is separate from personal computer
(or workstation) 28 used by the agent to enter business
activities (e.g., catalog orders or service calls). In
the integrated agent station 22, the agent's personal
computer (or workstation) 30 is used to make connections
with system 10 and has a card 31 for making the
connections and controlling handset 32. Agent stations
20, 22 are used by the agents to interact with system 10
and are controlled by call router 18 via X.25 command
messages transmitted over network 14, as is described in
detail below.
External host processor 34 contains business
databases (e.g., order entry, service schedules) used by
the operator of ACD system 10. Host processor 34 can be
directly connected to router device 18 by an external
processor interface 36 or can be remotely located from
call router 18 and connected to it via a network services
interface 16. The other components of system lo are
automated attendants 38, 40 (either directly connected to
call router 18 at a set of B channels or connected by an
interface 16 and telephone network 14), agent supervisor
station(s) 42, and system manager station(s) 43.
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Automated attendant 38 or 40 is a system for mechanized
interaction with the caller. It can play prompts and
receive tone signals from caller 12 used, e.g., by call
router 18 in determining which agent to route the
incoming call to. In this ISDN ACD embodiment, such
devices can appear either as mechanized agent stations
with ISDN interfaces (attendant 40 in Fig. 1) or as ISDN
B-channel terminations on the router device (attendant 38
in Fig. 1). A voice response unit (VRU) can be employed
in place of automated attendant 38 or 40 to play messages
in addition to playing prompts and receiving tones.
Agent supervisor station 42 provides an interface for the
agent supervisor to obtain agent performance information
(collected by call router 18). System manager station 43
provides an interface for the system manager to the
monitoring, diagnostics and maintenance capabilities of
ACD system 10.
In the presently preferred embodiment, ACD system
10 employs the integrated services digital network (ISDN)
in order to carry out the switching of calls from an
incoming caller 12 to one of plurality of agent stations,
to receive information on the status of the agent
stations 20, 22, and to perform other communication and
control functions. Network service interfaces 16 thus
employ the ISDN interface to a telecommunications network
as defined by international and domestic U.S. standard
bodies. The interface supports a combination of circuit-
switched and packet-switched information transfers with a
separate message-based signalling channel for connection
control. There are two major types of ISDN interface: a
basic rate interface (BRI) at 144 kb/s and a primary rate
interface (PRI) at 1544 kb/s (North America or Japan) or
2048 kb/s (Europe and most other regions). In the BRI,
there are two 64 kb/s bearer (B) channels used for voice,
data or other digitally encoded messages and a single 16
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Kb/s delta (D) channel used to transmit status and other
control messages between call router 18 and the other
components. In the PRI, there are 23 (US) or 30 (Europe)
B channels and one (64 kb/s) D channel. Agent stations
20, 22 typically employ BRIs, and call routers 18
typically employ BRIs in small systems (e.g., less than
50 agent stations) and PRIs in large systems. With these
interfaces there is real time simultaneous transmission
of control messages to the agent stations over the D
channel at the same time that there is normal telephone
operation over a B channel and transmission of status
messages over a B channel or D channel. Communications
between agent stations 20, 22 and host processor 34 could
be over a B channel or the D channel, using either
circuit-switched or packet-switched communication.
Interface characteristics and capabilities are described
in W. H. Harman and C. F. Newman, "ISDN Protocols for
Connection Control", IEEE Journal on Selected Areas in
Communication, Vol. 7, No. 7, September, 1989, and
Stallings, W., "Tutorial, Integrated Services Digital
Networks (ISDN)", (Second Edition 1988), Library of
Congress No. 87-83433, IEEE Catalog No. EH0270-9, and
Bocker, P., "ISDN, The Integrated Services Digital
Network, Concepts, Methods, Systems" (Springer-Verlag
Berlin, Heidelberg 1988).
Internationally, the ISDN standards are defined by
the CCITT I series of recommendations (I.110-I.470). The
standards most directly relevant to the invention are
1.430/431 (physical layer), 1.440/441 (link layer), and
1.450/452 (network layer). The call transfer function
used in the invention, described in more detail below,
can be implemented by proposed standards which have been
prepared in the U.S. in domestic standards group TlS1.
(See Call Transfer Service, ANSI Standards Group TlS1.1,
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Document TlS1.1 89-467).
Other ISDN call transfer functions that can
be employed have been precisely defined for and are
employed in commercially available telecommunications
vendor products supporting the ISDN interface in the U.S.
For example, the commercially available AT&T 5 ESS
switching product employs ISDN call transfer, as
described in AT&T 5ESS Switch, ISDN Basic Rate Interface
Specification, 5E6 Generic Program, Document 5D5-900-
321, Part VA, Section 3.2.4.
Agent status and control messages aretransmitted according to the X.25 standard, which is an
internationally standardized (CCITT) network service
interface between data terminal equipment and a packet
data network. Support of X.25 terminal equipment over an
ISDN network service interface, as employed in the
invention, is standardized in CCITT recommendation X.31.
A common basic hardware platform that can be
employed for integrated agent station 22, router device
18, agent supervisor station 42 and system manager
station 43 is a personal computer or workstation with an
ISDN terminal adapter card. For example, the platform
can be implemented with an AST model 80386/25 personal
computer running Interactive Systems Corporation UNIX
tversion 386/ix) as a processing platform and a model BP-
100C terminal adapter card (from Teleos Communications,
Inc. Eatontown, NJ) with a UNIX driver to provide the
ISDN interface. The functional roles for agent station
22, call router 18, agent supervisor station 42 and
system manager station 43 are determined by software.
The displays for the personal computers or workstations
at stations 22, 42 and 43 and router 18 can use OSF/Motif
as a basis for a user interface. (A less expensive
integrated agent station 22 may be based on IBM XT-Class
or AT-Class personal computers, but in this case, the
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agent software must run on MS/DOS and not UNIX. )
Nonintegrated, low-price, agent station 20 can employ
ISDN integrated circuits from Advanced Micro Devices,
Sunnyvale, CA and be programmed as a stand alone
application. Other computers (e.g., mainframes or
minicomputers) with ISDN interfaces can also be used for
call router 18. A fault tolerant computer available from
Stratus or Tandem Computer would be advantageous in
providing performance (particularly in large systems) and
reliability. Fault tolerant computers provide for
continued operation despite system hardware and software
failures.
Referring to Fig. 3, the software architecture for
agent station 22, call router 18, agent supervisor
station 42 and system manager station 43 (the last two
components are shown in a combined manager/supervisor
station 42/43) is shown. Agent station 20 has the same
architecture as shown for station 22. In Fig. 3,
combined managerJsupervisor station 42/43 is shown
directly connected to call router 18, contrary to the
connection through ISD~ interfaces and the telephone
network shown for agent supervisor station 42 and system
manager station 43 in Fig. l; either implementation can
be employed. The architecture for system manager station
43 is the same as for agent supervisor station 42; in
fact, the primary difference between these two stations
is the access to different types of data. Agent station
22 is typically connected to the network employing a BRI,
and call router 18 can use either a BRI or a PRI.
For both agent station 22 and call router 18,
com~-lnications driver layer 44 (a UNIX version of the
Teleos driver for product BP-lOOC) translates the
messages coming from network 14 to ISDN events and X.25
events. Communications driver layer 44 then interfaces
to a network interface layer 46 which translates the ISDN
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events and X.25 events to and from the events as seen by
the actual ACD application.
In agent station 22, the agent application is
embodied in agent state machine 48. (The agent states
are described in Fig. 4 and the accompanying text.)
Inputs to and from the agent are managed by the agent
interface subsystem 50, which employs the X-Windows
standard in integrated station 22.
In call router 18, network interface 46 feeds
event handler 52, which tracks the system state as seen
by call router 18 and filters incoming events to notify
appropriate subprocesses. Event handler 52 includes a
state manager, which is responsible for updating call and
agent states associated with any router event in an agent
state table. Routing events are processed by routing
interpreter 54, which translates user-programmed call
routing (depending on the particular ACD application)
into a means for selecting which agent station is to
receive an incoming call, as is discussed in detail in
connection with Fig. 6 below. Actions selected by
routing interpreter 54 are executed by event handler 52.
In call router 18, network interface layer 46 and
communications driver layer 44 act as a receiving means
for receiving agent status messages and call arrival
messages from network 14, and routing interpreter 53 and
event handler 52 act a routing means that is responsive
to the receiving means and generates a routing signal (in
particular a call transfer request, as is explained below
in connection with Fig. 5) to network 14 to connect the
incoming call to an agent station.
Management information system (MIS) 56, which
employs a relational database (available from Informix
Software Inc., Menlo Park, CA), handles the historical
reporting function of ACD system 10. Historical data
including call records and agent results are passed from
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event handler 52 to MIS system 56, to be stored as tables
in the relational database. Reports are prepared as
responses to database que~ies and may be accessed
directly by an agent supervisor or system manager.
Event handler 52 queries MIS 56 at user sign-on
(at agent stations 20, 22, agent supervisor station 42,
or system manager station 43) for password validation and
other user data. MIS 56 is initialized by the system
manager station 43 at system installation. In subsequent
system start up procedures, start up data are extracted
by query from permanent storage in the database.
Database queries use the Informix version of Structured
Query Language (SQL), an evolving standard for relational
databases. The agent may also access his own historical
performance by database query (not shown for simplicity
in Fig. 3).
The system manager at system manager station 43
can configure the ACD system (e.g., assign agents to
pools) and program call routing in the ACD, by a program
editing and compilation capability of manager state
machine 58. A compiled program is entered into the
system by invoking appropriate routines in event handler
52; for efficiency the program itself may be sent by a
direct link (not shown in the Fig. 3) to routing
interpreter 54. Event handler 52 provides manager state
machine 58 with alarms and other status information
necessary for real-time monitoring of system performance.
Agent supervisor station 42 and system manager
station 43 have their own state machines 58 tied to call
router 18 and MIS system 56 by local or remote
networking. In Fig. 3, for simplicity, the linkage is
shown as local, and in Fig. 1 it is shown as remote. If
the supervisor or system manager station is remote, then
the manager state machine communicates through
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communications software, a network service interface 16
and network 14 in the linkage to event handler 52 and MIS
system 56. Manager interface 60 interactively displays
current system status and alarms and provides interactive
displays to maintain, diagnose, program, and configure
the ACD system.
In a small configuration, call router 18, agent
supervisor station 42 and system manager station 43 can
share a single processing platform. In larger
configurations, the MIS function of call router 18 may
have a dedicated processor for improved performance, and
the agent supervisor and system manager displays may be
off-loaded to individual management stations.
Information to be displayed is determined by management
identity (i.e., agent supervisor or system manager) as
established at sign-on. Also, if an agent supervisor is
to be capable of performing also as an agent, then his
station will also incorporate the functions of an agent
station 22.
Agent stations 20, 22, call router 18, and the
other components of ACD system 10 are programmed to
provide the agent states, agent selection, call transfer
function, and other functions described herein.
O~eration
Before discussing the typical operation of ACD
system 10 in selecting an agent to handle an incoming
call and routing the call to that agent, the agent states
for the agent stations will be discussed in detail, with
reference to the agent state diagram of Fig. 4. The
agent station transitions through a number of states
which are visible to the agent at the CRT or other
interactive display at the agent station and logged at
call router 18. Each state involves a change of display
screen in at least one window (some states could have
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more than one screen). A variety of functions could be
accessible from within particular states, and would
result in an update of the display rather than different
screens. The agent can initiate state transitions or
function within states by interacting with command keys
provided at the interactive display. In Fig. 4, agent
states are shown in circles, and keys entered by the
agent to initiate state transitions and messages
displayed to the agent in going between states are shown
adjacent to arrows between states.
The major distinction bet~een two groups of states
in Fig. 4 is whether or not the agent is signed on, i.e.,
identified to ACD system 10 as working; when not in use,
the agent station is normally in the IDL~ state. By
pressing the sign-on key, the agent transitions through a
SIGN-ON state in which he or she provides identification,
password, and any session-dependent parameters to call
router 18 and is given authorization to work by receiving
a sign-on message. The sign-on procedure establishes an
X.25 virtual circuit between each agent station and call
router 18, and changes of agent state of significance to
call router 18 are communicated to call router 18 by X.25
messages. Similarly, the agent can end her or his work
session by pressing the sign-off key from the IDLEs
state. After obtaining ap~roval and providing any
necessary session wrap-up information, the agent is given
authorization to stop working by receiving a sign-off
message. While signed on, any incoming or outgoing calls
that the agent may make are considered business calls and
are logged at call router 18 and reported to system
manager station 43. ;:hile signed off, the agent may
still initiate or receive calls, such as personal calls,
but these are not reported to call router 18; when signed
off, call router 18 does not transfer calls to the agent.
In the event of a failure at call router 18, the agent
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may still operate in a "degraded" mode by sending and
receiving calls while signed off. By pressing a by-pass
key, the agent may transition directly to the IDLEN state
from any other state; this provides a quick escape
capability for the case of system failure or other
unexpected trouble.
There are five "telephony" states (SETUP, IDLE,
HOLD, RINGING and ACTIVE) and two "test" states (TEST and
CONFIGURE) which are used in a similar though not
identical way when the agent is signed off or signed on.
In the state dia~ram, these are denoted by a subscript
'S' for "signed on" or a subscript 'N' for "not signed
on". For example, the TESTS state provides agent station
tests while signed on, and the TESTN state provides agent
station tests while not signed on. These will be
different sets of tests (with some overlap), since some
hardware-oriented tests should be done only while signed
off, and some communications-oriented tests require the
assistance of call router 18 (e.c., X.25 loopbac~ between
the agent and the router) and therefore should be done
while signed on.
While signed on, the agent is in the lower half of
the state diagram and can be in the following states.
IDLEs: This state identifies the agent as
working, but not willing to receive calls. The agent may
use this state for work not related to a specific call or
for rest time. The agent is brought into this state
after signing on, and can access test and configuration
features from this state. An agent may also make
outgoing calls or sign-off from the IDLEs state. In
generai, transitions into the IDLES state are made by
pressing the IDLE key.
READY: When in this state, the agent is ready to
receive incoming calls. These calls are transferred from
call router 18 according to the protocol shown in Fig. 5
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and discussed below; the call transfer is referred to as
an incoming-call message in the Fig. 4 state diagram. An
agent may also make outgoing calls from the READY state
by pressing the call key, or make her/himself unavailable
for incoming calls by pressing the IDLE key. There is an
inherent synchronization issue for any transition out of
the READY state; an incoming call could be arriving while
the agent is trying to transition into another state.
Therefore, the transitions marked with an asterisk (*) in
the Fig. 4 state diagram undergo a synchronization
protocol discussed below in connection with Figs. 7A and
7B. If there is an incoming call in process, that call
takes priority over the agent making an outgoing call or
going idle. This synchronization is fast enough to
appear transparent to the agent; ringing will begin, and
the button the agent pressed will be ignored. If the
incoming caller disconnects, a disconnect message is sent
to the agent station, which brings the agent station back
to the READY state. While the agent is signed on,
incoming calls are accepted by the agent station only if
they are authorized by call router lB. Procedures for
authorization are discussed in connection with Fig. 5.
In general, transitions into the READY state are made by
pressing the READY key.
SETUPs: This state is used for making an outgoing
call. Digits are collected and parsed by the agent
station, to provide speed-dialing and internal number
plans. The SETUPs state is entered by pressing the call
key from either the IDLEs or the READY state.
RINGINGs: This state is passed through when
receiving an incoming call. The incoming transfer
message is provided at the end of the transfer protocol,
given in Eig. 5. When transitioning from the READY state
to the RINGINGs state, a ringing tone is presented to the
agent's headset 26, followed in some applications by a
2123326
-- 19 --
VRU message containing information about the nature of
the call (e.g., caller identification, historical
information about this customer, type of service
request). The agent then answers the call by pressing
the answer key; alternatively he/she may be transitioned
directly into the ACTIVEs state via an answer message
generated by call router 18. The call is then assigned
to a call appearance on the visual display at the agent
station. If the incoming caller disconnects, a
disconnect message is sent to the agent station, which
message brings the agent back to the READY state.
ACTIVES: Whenever the agent is talking to a
customer while signed on, he or she is in this state.
Multiple call appearances are handled by placing
additional calls on hold, with calls on hold appearing as
in the ACTIVES state. Transitions out of the ACTIVEs
state are made by pressing either the READY key (taking
the agent to the READY state), the IDLES key (taking the
agent to the IDLES state), or the WRAP-UP key (taking the
agent to the WRAP-UP state). In all of these cases, the
call is terminated if it has not already been terminated
by the customer.
HOLDS: In this state, the agent may change to
another call appearance in order to consult, transfer or
make an outgoing call. An agent may change between call
appearances by pressing a call appearance (CA) key, which
changes the agent station to the context of that call
appearance. Changing context from a call in the Actives
state puts that call appearance into the Holds state;
pressing the call appearance key corresponding to a call
in the Holds state will put that call appearance into the
Actives state. Functions such as call transfer require
two call legs, one of these being in the Actives state
and the other being in the Holds state.
212332~
- 20 -
WRAP-UP: In this state, the agent does any work
related to a given call which must be done before taking
another call, e.g., entering information about the sale
or making notations for call-backs.
TESTs: Any tests which can be done while signed
on are accessible from this state. Tests can include:
communications tests (X.25 loopback, Q.930 and Q.931
tests, link resets), applications tests (interworking
with particular applications), VRU tests, non-intrusive
agent instrument tests (headset function, memory
allocation, some PCTA and CPU diagnostics).
CONFIGURES: Any configuration parameters which
can be set while signed on are accessible in this state.
These include:
- password modification
- set manual or autoconnect call delivery mode
- reset agent pool assignment
While signed off, the agent is in the upper half
of the state diagram and can be in the following states:
IDLEN: This similar to the IDLEs state in that
all tests and calls originate from this state. However,
the agent station acts like a conventional telephone set
in this state and does not depend upon call router
messages for its operation. The agent station also does
not send X.25 messages to call router 18 in this state.
SETUPN: This is similar to the SETUPs state.
RINGINGN: This is similar to the RINGINGS state.
ACTIVEN: This is similar to the ACTIVEs state,
including the support of multiple call appearances. The
display in this case does not support account information
that would be available in the signed-on state.
HOLDN: This is similar to the Holds state.
TESTN: Any tests which can be done while signed
on are accessible from this state. Tests can include
21 2332G
21 60412-2098D
limited communications tests (Q.930 and Q.931 tests, link rests)
and agent instrument tests (headset function, memory allocation,
PCTA and CPU diagnostics, and powering tests).
CONFIGUREN: Any configuration parameters which can
be set while signed on are accessible in this state.
These include:
- set station ID
Two additional states may optionally be provided in
the sign-off condition to achieve full symmetry in signed-on and
signed-off states. These are READYN and WRAPUPN. The state
descriptions are similar to those of the READYS and WRAPUPS
states, but in the signed-off condition, the state transitions
are managed by agent state machine 48 in the agent station.
There is no synchronization for transitions out of ReadyN, since
the call router will not be available to handle incoming calls.
The routing of an incoming call to an agent station is
illustrated in Figure 2; the protocol used in transferring the
call from call router 18 to the agent station is shown in Figure
5, and the decision tree analysis employed in deciding which
agent should receive a call is shown in Figure 6. In general,
when an incoming call is made (indicated by ~1" in Figure 2),
call router 18 decides which agent station should receive the
call, establishes a call with that agent station (indicated by
"2" in Figure 2), and then instructs telephone network 14 to
connect the incoming call directly to the agent station
(indicated by "3" in Figure 2) and drops out of the connection.
When an incoming call is made by caller 12 to a
telephone number for ACD system 10, network 14 provides a call
~ 21 23326
22 60412-2098D
arrival message to call router 18 indicating that a call has
been set up and optionally including the calling line
identification (CLID). A call reference number is assigned to
this call at the ISDN interface 16 for call router 18, for
example, CR=1 (Figures 2 and 5).
Call router 18 determines which agent station should
receive the call by reference to logic in routing interpreter 54
and data managed by event handler 52. The agent station that is
selected is one that is in the READY state (event handler 52
maintains a continuously updated agent state table of the states
of signed-on agent stations by X.25 messages); other factors
such as agent capabilities, agent identity, agent geographic
location, connection cost, service request type, dialed number,
caller identity and location can be considered in selecting an
agent according to user-programmed routing patterns in routing
interpreter 54.
For an incoming call, the initial stage of routing is
to determine the particular ACD application (e.g., sales or
service) represented by the call, on the basis of dialed number,
CLID, incoming trunk (BRI or PRI), and possibly interaction with
an automated attendant or VRU. Once the application is known,
the remaining routing logic includes a user-programmed sequence
of steps such as is shown in Figure 6. Separate programs can be
developed for multiple applications and compiled into logic
flows kept in routing interpreter 54.
Figure 6 shows a logic flow for call handling by call
router 18, describing what happens to the call from the moment
it enters the system until its processing has been completed.
_ .,,
22a 2123326 60412-2098~
In general, a call is queued before one agent pool while the
call goes on hold for 15 seconds. If an available agent has not
been identified to answer the call in that time, the call is
queued before a second agent group and an announcement is played
to the incoming call by VRU 38 or 40. If the call is not
answered within a further 10 seconds, it is queued before a
third agent
2123326
-
- 23 -
group as well. The ACD system 10 then plays an
announcement repeatedly (separated by hold periods) until
the call is handled. Routing interpreter 54 provides the
logic of the call flow shown in Fig. 6. Event handler 52
performs events that are required in each stage in the
traversal of the call flow. An advantage of separating
these functions is that changes in call flow at different
sites or changes in flow made at one site can be
implemented solely in routing interpreter 54.
Specifically, referring to Fig. 6, event handler
52 initiates call handling and giv-es control of the call
to routing interpreter 54 for selection of the first
routing event. Routing interpreter 54 determines the
first action (add the call to Agent Pool 1) and gives
control to event handler 52 for execution. If there are
agent stations in the READY state, event handler 52
selects one according to agent queueing rules (e.g.,
first in first out), invokes logic to deliver the call
(the Fig. 5 protocol), and terminates the routing process
for this call. Otherwise event handler 52 returns
control to routing interpreter 54 to determine the next
step (hold 15 seconds). Event handler 52 then executes
this step by setting a timer for 15 seconds. If an agent
frees up during this 15 second period, the event is
reported to the event handler 52, which assigns the agent
to one of the waiting calls according to priority. If no
agent becomes available for this call, at the expiration
of the 15 second time, event handler 52 returns control
to routing interpreter 54 for selection of the next step
(add agent pool 2). Assuming no agent is immediately
available, control is returned to the routing interpreter
54 to determine the succeeding step (hold 10). This is
handled as above, with return of control to the routing
interpreter 54 at the expiration of the 10 second time
period to identify the next step (play message number 4,
21Z3326
-
- 24 -
which has been arbitrarily numbered in ~ig. 6). Event
handler 52 plays the message indicated, allowing for
interruption of the message and delivery of the call if
an appro~riate agent should come free. At the end of the
message, event handler 52 again returns control to
routing interpreter 54 for selection of the next step
(add agent pool 3). The hold 5 seconds, play 10 seconds,
and hold 10 seconds events are handled as above. After
the second hold 10 seconds, routing interpreter 54 sees
the hold 5 seconds as the next event, due to the loopback
in the logic. The call routing pEocess terminates when
an agent becomes ready for assignment to the call in any
of the pools being searched. When that occurs, event
handler 52 delivers the call and terminates the routing
process.
Referring to Fig. 5, having selected an agent
station to receive the incoming call, call router 18
sends a call pending X.25 message to that agent station
to alert it that it will be receiving a call. Call
router 18 then initiates a call to that agent station,
resulting in an associated setup call reference CR=2 at
its ISDN interface 16 and a setup call reference CR=3 for
the connection to the agent station at the agent
station's interface 16. Network 14 provides a call
proceeding acknowledgment for CR=2 for call router 18,
lnd the agent station provides an optional call
proceeding acknowledgment for CR=3 to network 14. (Items
in brackets on Fig. 5 are optional.) When the agent
station line is ringing, there also is an alerting CR=3
message provided to network 14, and this in turn triggers
an alerting CR=2 message to call router 18 to inform call
router 18 that the connection on CR=2 is now ringing.
When the agent answers, there is a connect CR=3 message
provided to network 14 and an acknowledgment by the
network to the agent station that it has received the
2 1 23326 604l2-20g8D
connect message. (If the agent does not answer, the condition
will be reported as an alarm, and the next available agent will
be selected.) Network 14 then provides a connect message to
call router 18 to inform it that the agent has answered, and
call router 18 provides a connect acknowledgment to the network.
(This connection is indicated by '`2" on Figure 2.) Call router
18 puts the agent station on hold by a hold CR=2 message to the
network, and the network acknowledges that message. Call router
18 then provides a transfer pending call X.25 message to the
agent station to inform it that a call is being transferred to
it. At this point, call router 18 connects to the incoming call
at CR=1 by providing an alerting CR=1 message and a connect CR=1
message to the network. (This connection is indicated by "1" on
Figure 2.) The network provides a connect acknowledgment CR=1
message, and call router 18 then initiates the transfer function
to tie the telephone connections at CR=1 and CR=2 to each other
over the ISDN telephone network 14. (This connection is
indicated by "3" on Figure 2.) When this has been successfully
carried out by the network, it provides a transfer acknowledge
message to call router 18. Call router 18 then provides a
transfer completed X.25 message to the agent station and
receives an X.25 transfer received message from the agent
station. If the agent station is an automated agent station,
the automated agent may be activated to place it in a proper
state, as indicated by the optional force transition (answer)
message. Optionally, call router 18 can provide a tone or other
indication to the agent station. This would require placing the
caller on hold and reestablishing the connection to the agent
_ 2123326
26 60412-2098D
until the transfer is effected. After the transfer has been
completed, the network disconnects call router 18 from CR=1, and
call router 18 releases the connection and receives an
acknowledgment from the network. The network then similarly
disconnects CR=2, and call router 18 releases CR=2 and receives
a release complete message from the network.
The protocol of Figure 5 is a method for automatically
rerouting an incoming call from a first network station (call
router 18) to a second network station ~the chosen agent
station) where the selection of the second network station takes
place on a per-call basis. This protocol includes three
important features.
First, the call pending (call #) message in the
protocol provides pre-notification to the destination agent
station of information as to the nature of the incoming
telephone call before the call is actually delivered. This pre-
notification may include information provided by call router 18
to condition acceptance or rejection of the call by the agent
station. Specifically, pre-notification is used to validate the
call for acceptance by the agent station, i.e., a caller
description determined by call router 18 on the basis of CLID
which could then be displayed at the agent station. Pre-
notification may also be used to provide other ancillary call
information to the agent station prior to call arrival.
Second, the Figure 5 protocol provides for backward
communication in the call rerouting procedure. In Figure 5
there is a backward acknowledgment to the router's sending of
the call pending message (which acts as an incoming call
- 21 23326
27 60412-2098D
notification signal) through the communication of the alerting
and connect messages (acting as response signals) from the
destination agent station to call router 18. Since only router-
directed messages can be received in the READY state, the
alerting and connect messages announce to the router that the
router's call has been accepted by the agent station. An
explicit backward acknowledgment could also be provided to
achieve the same goal. Use of backward communication from the
agent station to call router 18 permits trying alternative
destinations for the call. If the selected agent does not
establish a connection in response to the setup message, the
next available agent is selected as required. In general, call
router 18 can select an alternative destination if the first
selection fails. Moreover, ringing (and hence the initiation of
telephone company charges) is delayed until an acceptable
destination has been determined. Also the call can be rejected
if an acceptable destination cannot be found, something that
would probably have the most benefit in a non-ACD application.
A further advantage of the backward acknowledgment is the
ability to explicitly tag a call with an identity that has
network-wide significance. If several calls are passed from
call router 18 to the agent station, then the backward
acknowledgments will assure that call identities assigned by
call router 18 are preserved by the agent station. This feature
is used to assure that all stages of a call can be tracked by
call router 18 regardless of the number of agents or VRU's
involved in its handling. Finally, the backward acknowledgment
procedure provides the opportunity for explicit indication of
f
- 2 1 23326
28 60412-2098D
connection establishment, since a tone can be placed on the line
to the caller or agent which will disappear with the act of
transfer.
Third, the Figure 5 protocol allows for network call
redirection to be based on any information obtainable about the
call. This includes the calling line identity or any tone
responses to prompts.
Automated attendants 38, 40 can be used to obtain
additional information that is used by call router 18 in
determining which agent station should receive an incoming call.
When call router 18 receives a CLID or other identifying
information for the incoming call, that information can be used
to call up the customer's records from external host processor
34 and provide them to the agent station as required.
Information entered by an agent during a call and during a
WRAPUP state is transmitted to external host processor 34 for
recording. The interface to external host processor 34 allows
ACD system 10 to interwork with other data processlng systems
specific to the ACD business (e.g., billing or inventory).
Examples of such interfaces are described in Switch-Computer
Applications Interface Working Document, ANSI Standards Group
TlS1.1 89-231, and Emil Wang, "Intelligent Call Processing in
Automatic Call Distributors", Business Communications Review,
January-February, 1988 and embodied in the following products:
Call Path (IBM), Adjunct-Switch Application Interface (AT&T
ISDN/DMI User's Group), and Computer Integrated Telephony (DEC).
Figures 7A and 7B show partial state diagrams
illustrating procedures for synchronization and customization of
.
2 1 23326
29 60412-2098D
agent state transitions as seen by call router 18 and an agent
station. The same basic method is used both for state
synchronization and user customization of the state transition
diagram. In the latter case the objective is to allow states to
be bypassed, or transitions added or dropped, to accommodate the
requirements of particular ACD applications.
Figure 7A is a portion of the full agent state diagram
(Figure 4) considering only signed-on telephony states, without
the ability to make outgoing calls, and without transfer
functionality. Transition number 102, from the READY state to
the IDLE state, should be synchronized between the agent station
and call router 18. Otherwise, a new call could be directed by
call router 18 to the agent station (via transition 103) at the
same time the agent station is making the transition to idle.
Therefore transitions 102 and 103 need to be synchronized with
each other.
The method used for the agent station to synchronize
transitions with call router 18 is for the agent station to
request transitions, and wait for them to be granted by call
router 18. The request is done by sending a transition request
message from the agent station to call router 18, and the grant
is done by sending a forced response signal message from call
router 18 to the agent station. While waiting, the agent
station is effectively in an intermediate state, in which all
additional agent keystrokes are ignored.
A synchronized state transition for transition number
102 has the following message sequence. When the agent presses
the idle key from the READY state, a transition request message
;~
2 1 23326
60412-2098D
is sent to call router 18, which responds with a forced IDLE
response signal message in the event that no call is pending for
the agent. Otherwise the agent remains in READY until the
arrival of the call.
It would be possible for all state transitions to use
this protocol. However, better performance can be gained by
letting the majority of transitions be unsynchronized, with the
agent simply executing the state transition and notifying call
router 18 of its status by sending a transition notification
message. On Figure 7B, the transitions involving a transition
request are indicated by dashed lines, and the transitions
involving transition notifications are indicated by solid lines.
The agent station maintains a transition table giving the
appropriate transition type for each state transition. This may
be done in practice with a two-bit field for each transition,
where the allowed transition types are request, notify, ignore,
or error (not allowed).
In order to use this synchronization protocol to
customize the state diagram, one need only modify the transition
table in the agent station and allow call router 18 to use the
forced response signal message to return a different state than
the one requested. Call router 18 maintains a response table
that lists the appropriate forced response signal message to be
used in responding to each synchronized transition request.
Figure 7B illustrates the case where the Figure 7A agent state
diagram has been modified to prevent use of (effectively delete)
the WRAPUP state. To achieve this, transition 109 is changed to
a synchronized transition, and transitions 110 and 111 become
O,
. . .
2 1 23326
31 60412-2098D
errors in the transition table at the agent stations. In the
response table in call router 18, transition 109 is redirected
to the IDLE state, so that an agent pressing the WRAPUP key is
forced into the IDLE state.
The method can also be used to support customized
state diagrams on a per application basis. In this case the
transition table and a response table are developed for each
application, and an application field is added to the transition
messages. Once the call application is determined by call
router 18, it is communicated to the agent by X.25 message
(e.g., call pending). The agent station uses the application to
find the relevant portion of the transition table, and includes
the application in each transition request message, so that call
router 18 need not look it up. The response table similarly
determines the appropriate forced response signal message (by
application) for each synchronized transition request.
Another use for customized state diagrams is in
response to system load conditions. For example, the system may
reduce the number of agent states required for call handling if
many callers are already waiting for service. This could be
used if the WRAPUP state were normally used to enter descriptive
but non-essential information about a customer transaction, and
the system would eliminate the WRAPUP state whenever the number
of customers in queue exceeded a user-specified threshold
(either overall or per-application). The change from a normal
state diagram to an exceptional state diagram could also be
invoked on a per-call basis if a call's waiting time exceeded a
threshold. The above-described method can implement this
21 23326
32 60412-2098D
feature by treating normal and exceptional state diagrams as
distinct applications.
Other Embodiments
Other embodiments of the invention are within the
scope of the following claims.
For example, besides the ISDN interface, other network
service interfaces can work so long as they have the following
capabilities: call arrival signalling, control of call routing
by the call router, interconnection of the caller and agent
station, and communication of control messages from the call
router to agent stations and of status messages generated at
agent stations to the call router. These are purely connection
establishment and control capabilities. Because the router
communicates with the agent stations, the network interface does
not provide any specialized function ~such as agent monitoring)
related to the operation of the ACD. Hence this invention
requires only the ordinary communication capabilities of a
network service interface. The broadband ISDN interface (being
developed in international and domestic U.S. standard bodies,
CCITT recommendation I.121) may also be used when available.
The interface to call router 18 could employ common channel
signalling (CCS) associated with "800" service, e.g., as
described in G. G. Schlanger, "An Overview of Signalling System
No. 7", IEEE Journal on Selected Areas in Communications, Volume
SAC-4, Number 3, May,1986. The CCS interface could be used by
call router 18 to control routing of calls to agents where the
agent to router communication is still implemented by ISDN and
X.25. Specifically, the network could notify call router 18 of
21 23326
33 60412-2098D
a call attempt before a call is actually delivered to call
router 18, and call router 18 could then instruct the network to
send the call to the destination chosen by the router. In
addition to the CCS interface, call router 18 could use an X.25
interface for monitoring of agents.
In addition to communication over a public telephone
network, private networks or combinations of networks can also
be used. Examples include a PBX or virtual private network
(i.e., a network that is provided by the telephone company but
appears to the user to be a private network) employing ISDN, or
any local/metropolitan/wide area network (e.g., as standardized
in the IEEE 802 committees) with the above-listed connection
control capabilities provided at the network layer.
In an ISDN network, instead of having all
communication between the call router and agent station via X.25
messages, some of the communication could be by user-to-user
signalling service as being standardized by standards group TlS1
and documented in TlS1.1 89-144 April 25, 1989.
The agent stations can have different states than
those shown in Figure 4; what is important for practice of the
invention is that the agent station perform a function on behalf
of the overall system under the control of the call router.
Multiple call routers 18 and agent supervisor stations
42 may be used in large system configurations, and supervisor
station functions may be combined with agent station functions
if a supervisor is to act as an agent in periods of high system
load.
The different call router functions may be split up
- 2 1 23326
34 60412-2098D
and placed at different locations on the network; e.g., one
portion of the call router may be implemented at a separate
agent monitoring station that receives the agent status
messages, monitors the agent states, and communicates with the
agent stations and the remaining portions of the call router via
the network and network services interfaces.
Incoming calls to agent stations (instead of always
being blocked) may be screened by call router 18 for subsequent
handling. Specifically, the agent station may inform call
router 18 of a call arrival coming directly to the agent station
by an X.25 message to call router 18 for processing. Call
router 18 could then decide whether to accept or reject the
call, or whether to transfer the call to another agent station
selected by the routing logic. The arrival of the call would
not necessarily be visible to the agent at the agent station.
This arrangement allows for incoming calls to the ACD to be
received at different locations for different callers.
Features of the invention also may be applied in non-
telephone environments. Instead of routing telephone calls to
agents, the system could automatically establish a communication
connection between a service requesting station and one of a
plurality of agent service providing stations with application-
specific agent states. For example, an application station may
be capable of running programs concerned with various aspects of
the user's business, and a connection request could be assigned
to an available station running a program or accessing a data
file corresponding to the requested service. This would mean
that incoming connection requests or internal connection
-- 2 1 23326
34a 60412-2098D
requests could be directed to the stations best prepared to
handle the transactions. The application stations may still be
operated by human or mechanized means.
An example application could be defined by software
development within a Computer Aided Software Engineering (CASE)
environment (e.g., development systems available from DEC, IBM
or Hewlett-Packard). Agent states could be determined by active
CASE tool processes, data files in use, and active connections.
A call router 18 with knowledge of agent application states
would automatically direct internal or external requests for
information or software support to agents currently performing
related work. Additional automated agents would be represented
by centralized development resources.
Also in these non-ACD environments, network service
interfaces other than ISDN, PRI and BRI interfaces can work so
long as they have the capabilities of call arrival signalling,
control of call routing by the call router, interconnection of
the caller and agent station, and communication between the
agent station and call router. For example, the B-ISDN network
service interface could control connections involving
transmission of digital data signals or transmission of image or
video signals. Also, the network could be an X.25 data network
with call redirection or deflection capabilities, a local area
network, or a wide area network. The system would have a
receiving means that receives agent state messages and service
request messages from the network, and would also have routing
21 23326
34b 60412-2098D
means that generates a routing signal that is provided to the
network to connect the service requesting station via a
communication connection to the agent application station.
