U.S. patent number RE36,051 [Application Number 08/639,300] was granted by the patent office on 1999-01-19 for automatic call distribution network with call overload system and method.
This patent grant is currently assigned to Rockwell International Corporation. Invention is credited to David J. Adams, Christopher G. Culp, Wayne L. Harbuziuk.
United States Patent |
RE36,051 |
Adams , et al. |
January 19, 1999 |
Automatic call distribution network with call overload system and
method
Abstract
An automatic call distribution network (10) with an originating
automatic call distributor (ACD) (12A) which transfers a received
call to a destination ACD (12B) through an external telephonic
network (24), a call overflow system (32) with a central processing
unit (16A) at the originating ACD (12A) to compile data relating to
an overflow call to be transmitted through the external telephonic
network (24) to the destination ACT) (12B) of at least one of the
types of information of: identification of a selected gate (26B) of
the destination ACD (12B) to which the overflow call is to be
routed, identification of the originating ACD (12A), a time
information relating to a time the overflow call was in a queue at
the originating ACD (12A), an ANI number representation of a
telephone number of the call received at the originating ACD (12A)
and a priority level of the overflow call, the central processing
unit (16A) at the originating ACD (12A) sending the compiled data
to the destination ACD (12B) to route the call at the destination
ACD (12B).
Inventors: |
Adams; David J. (Warrenville,
IL), Harbuziuk; Wayne L. (Wheaton, IL), Culp; Christopher
G. (Wheaton, IL) |
Assignee: |
Rockwell International
Corporation (Costa Mesa, CA)
|
Family
ID: |
22507402 |
Appl.
No.: |
08/639,300 |
Filed: |
April 24, 1996 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
144170 |
Oct 27, 1993 |
05384841 |
Jan 24, 1995 |
|
|
Current U.S.
Class: |
379/242; 379/309;
379/266.02; 379/266.03; 379/266.04 |
Current CPC
Class: |
H04M
3/51 (20130101); H04M 3/5237 (20130101); H04M
2242/22 (20130101); H04M 3/42042 (20130101); H04Q
3/72 (20130101); H04M 3/42059 (20130101) |
Current International
Class: |
H04M
3/50 (20060101); H04M 3/51 (20060101); H04Q
3/72 (20060101); H04M 003/54 () |
Field of
Search: |
;379/266,265,225,220,221,210,211,212,207,93,94,95,45,309
;370/60,110.1,259 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Technical Reference 41449, AT&T Integrated Services Digital
Network (ISDN) Primary Rate Interface Specification, May 1992 pp.
I-i-IV-O-116 Look-Ahead Interflow pp. 8-97-8-132..
|
Primary Examiner: Hunter; Daniel S.
Attorney, Agent or Firm: Welsh & Katz, Ltd.
Claims
We claim:
1. In an automatic call distribution network having means for
transferring a call received at .[.a originated.]. .Iadd.an
originating .Iaddend.ACD to a destination ACD through an external
telephonic network, the improvement being a call overflow system,
comprising:
means at the originating ACD to compile data .[.relating to.].
.Iadd.of .Iaddend.an overflow call to be transmitted through the
external telephonic network to the destination ACD including .[.at
least one of the types of information of (a) identification of a
selected gate of the destination ACD to which the call is to be
routed in addition to the destination ACD telephone number (b).].
identification of the originating ACD .[.(c) a.]. .Iadd.and at
least one of the types of information of (a) identification of a
selected gate of a plurality of gates available through the
destination ACD to which the call is to be routed which identifier
is different from and in addition to the destination ACD telephone
number (b) .Iaddend.time information .[.relating to.]. .Iadd.of
.Iaddend.a time the .[.overflow.]. call was in a queue at the
originating ACD .[.(d) an ANI number representation of a telephone
number of the call received at the originating ACD.]. and .[.(e).].
.Iadd.(c) .Iaddend.a priority level of the .[.overflow.]. call
.Iadd.assigned by the originating ACD.Iaddend.; and
means at the originating ACD for sending the compiled data in a
SETUP message with the overflow call in an ISDN network to the
destination ACD to route the overflow call at the destination
ACD.
2. The automatic call distribution network of claim 1 in which all
types of information (a), (b).[.,.]. .Iadd.and .Iaddend.(c).[., (d)
and (e).]. are included in the data.
3. The automatic call distribution network of claim 1 including
means at the originating ACD for selectively preventing the sending
of data including information relating to identification of the
selected gate of the destination ACD to which the overflow call is
to be routed.
4. The automatic call distribution network of claim 1 in which the
data is sent to a destination ACD in which includes means
responsive to identification of the selected gate in the data
received from the originating ACD to connect the overflow call to a
line associated with said gate.
5. The automatic call distribution network of claim 1 in which the
destination ACD responds to identification of the originating ACD
in the data received from the originating ACD to track data
relating to the call received at the originating ACD.
6. The automatic call distribution network of claim 1 in which the
time information relating to the overflow call is delay time in
which the overflow call was in queue at the originating ACD.
7. The automatic call distribution network of claim 6 in which the
destination ACD responds to the call at the originating ACD in the
data received from the originating ACD to determine a total delay
time of the overflow call.
8. The automatic call distribution network of claim 1 in which the
.Iadd.originating ACD further sends an ANI number as part of the
compiled data and the .Iaddend.destination ACD responds to the ANI
number representation in the data received from the originating ACD
to send information .[.relating to.]. .Iadd.of .Iaddend.the
identified type of overflow call received at the destination ACD to
an internal telephonic unit at the destination ACD.
9. The automatic call distribution network of claim 1 in which the
destination ACD responds to receipt of the priority level for
placing the overflow call in a queue at the destination ACD in
accordance with the assigned priority level of the call.
10. The automatic call distribution network of claim 1 including
means at the originating ACD for transferring the overflow call to
another ACD in response to the destination ACD not accepting the
overflow call from the originating ACD.
11. In an automatic call distribution network having a originating
ACD and a destination ACD both interrelated through an external
telephonic network, improvement being a method of transferring
.[.an overflow.]. .Iadd.a call, comprising the steps of:
compiling data at the originating ACD .[.relating to.]. .Iadd.of
.Iaddend.an overflow call to be transferred through the external
telephonic network to the destination ACD including .[.at least one
of the types of information of (a) identification of a selective
gate of the destination ACD to which the call is to be routed in
addition to the destination ACD telephone number, (b).].
identification of the originating ACD, .[.(c).]. .Iadd.and at least
one of the types of information of (a) identification of a selected
gate of a plurality of gates available through the destination ACD
to which the call is to be routed which identifier is different
from and in addition to the destination ACD telephone number, (b)
.Iaddend. a time information .[.relating to.]. .Iadd.of .Iaddend.a
time the .[.overflow.]. call was in a queue at the originating ACD,
.[.(d) an ANI number representation of the telephone number of the
call received at the originating ACD.]. and .[.(e).]. .Iadd.(c)
.Iaddend. a priority level of the .[.overflow.]. call
.Iadd.assigned by the originating ACD.Iaddend.; and
sending the compiled data in a SETUP message with the overflow call
in an ISDN network from the originating to the destination ACD to
route the overflow call at the destination ACD.
12. The method of claim 11 including the step of selectively
preventing the sending of data including information relating to
identification of the selected gate of the destination ACD to which
the call is to be routed.
13. The method of claim 11 including the step of connecting the
overflow call to a line associated with the selected gate at the
destination ACD in response to receipt of the identification of the
selected gate in the data received from the originating ACD.
14. The method of claim 11 including the step of tracking data
relating to the call originally received at the originating ACD in
response to receipt at the destination ACD to the identification of
the originating ACD in the data received from the originating
ACD.
15. The method of claim 11 including the step of determining a
total delay time of the call in the call distribution network in
response to the receipt of the delay time of the overflow call in a
queue at the originating ACD in the data received from the
originating ACD.
16. The method of claim 11 including the step of sending
information to an internal telephonic unit at the destination ACD
relating to the identified type of overflow call received at the
destination ACD in response to receipt at the destination ACD of
the ANI number representation in the data sent from the originating
ACD.
17. The method of claim 11 including the step of placing the
overflow call in a queue at the destination ACD in accordance with
the assigned priority level of the call in response to receipt at
the destination ACD of the priority level of the overflow call in
the data sent from the originating ACD.
18. The method of claim 11 including the step of transferring the
overflow call from the originating ACD to another ACD. .Iadd.
19. For use in a call distribution network having at least an
originating switch and a destination switch, a system
comprising:
means for determining an overflow condition related to operation of
the originating switch;
means for compiling data identifying the originating switch and a
priority level assigned by the originating switch to a call to be
overflowed to the destination switch in response to the overflow
condition; and
means for sending the compiled data from the originating switch to
the destination switch. .Iaddend..Iadd.20. The system, as set forth
in claim 19, wherein the compiled data identifying the originating
switch comprises a site identification of the originating switch.
.Iaddend..Iadd.21. The system, as set forth in claim 19, wherein
the compiled data of priority of the overflow condition comprises
priority level information of the
overflow condition. .Iaddend..Iadd.22. The system, as set forth in
claim 19, wherein the compiled data of priority of the overflow
condition comprises time information of the overflow condition.
.Iaddend..Iadd.23. The system, as set forth in claim 19, wherein
the means for compiling data compiles data of operation of at least
one queue in the originating switch. .Iaddend..Iadd.24. The system,
as set forth in claim 19, further comprising a central processing
unit for operating the destination switch based on the compiled
data. .Iaddend..Iadd.25. A method for operating a call distribution
network having at least an originating switch and a destination
switch comprising the steps of:
determining an overflow condition of operation of the originating
switch;
compiling data identifying the originating switch and a priority
level assigned by the originating switch to a call to be overflowed
to the destination switch in response to the overflow condition;
and
sending the compiled data from the originating switch to the
destination switch. .Iaddend..Iadd.26. The method, as set forth in
claim 25, wherein the step of compiling data comprises the step of
compiling data identifying a site of the originating switch.
.Iaddend..Iadd.27. The method, as set forth in claim 25, wherein
the step of compiling data comprises the step of compiling data of
a priority level of the overflow condition. .Iaddend..Iadd.28. The
method, as set forth in claim 25, wherein the step of compiling
data comprises the step of compiling data of time information
associated with the overflow condition.
.Iaddend..Iadd. The method, as set forth in claim 28, wherein the
step of compiling data of time information comprises the step of
compiling data of operation of at least one queue in the
originating switch. .Iaddend..Iadd.30. An automatic call
distribution system comprising:
a first call distributing switch; and
a second call distributing switch coupled to the first call
distributing switch by a telephonic network;
the first call distributing switch compiling data of a call
received by the first call distributing switch, the compiled data
comprising (a) identification of the first call distributing
switch, (b) a priority level of the call assigned by the first
distributing switch, and (c) an intended routing of the call, the
first call distributing switch being capable of transferring the
compiled data and the call to the second call distributing switch
via the telephonic network, and
the second call distributing switch processing the call based on
the compiled data. .Iaddend..Iadd.31. The system, as set forth in
claim 30, wherein the data of identification of the first call
distributing switch comprises a site identification of the first
call distributing switch. .Iaddend..Iadd.32. The system, as set
forth in claim 30, wherein the data of priority of the call
comprises time information associated with the call.
.Iaddend..Iadd.33. The system, as set forth in claim 32, wherein
the time information comprises a length of time the call was in a
queue of the first call distributing switch. .Iaddend..Iadd.34. The
system, as set forth in claim 30, wherein the data of priority of
the call comprises data of priority level information associated
with the call.
.Iaddend..Iadd. The system, as set forth in claim 30, wherein the
data of routing of the call comprises data related to
identification of the call. .Iaddend..Iadd.36. The system, as set
forth in claim 35, wherein the data of identification of the call
comprises a calling party number representative of a telephone
number of the caller. .Iaddend..Iadd.37. The system, as set forth
in claim 35, wherein the data of identification of the call
comprises a called party number representative of a telephone
number dialed. .Iaddend..Iadd.38. The system, as set forth in claim
30, wherein the data of routing of the call comprises
identification of an application of the second call distributing
switch. .Iaddend..Iadd.39. The system, as set forth in claim 30,
wherein the telephonic network comprises a public telephonic
network. .Iaddend..Iadd.40. The system, as set forth in claim 30,
wherein the telephonic network comprises an ISDN system.
.Iaddend..Iadd.41. The system, as set forth in claim 30, wherein
the first call distributing switch determines whether the call
creates an overflow condition. .Iaddend..Iadd.42. The system, as
set forth in claim 41, wherein the first call distributing switch
compiles the data in response to the overflow condition.
.Iaddend..Iadd.43. The system, as set forth in claim 42, wherein
the first call distributing switch transfers the data to the second
call distributing switch in response to the overflow condition.
.Iaddend..Iadd.44. The system, as set forth in claim 43, wherein
the first call distributing switch transfers the data to the second
call distributing switch in a SETUP message. .Iaddend..Iadd.45. The
system, as set forth in claim 42, wherein the first call
distributing switch transfers the call to the second call
distributing switch in response to the second call distributing
switch accepting the call. .Iaddend..Iadd.46. The system, as set
forth in claim 42, wherein the first call distributing switch
transfers the data with the call to the second call distributing
switch in response to the overflow condition. .Iaddend..Iadd.47. A
method for processing a call received at a first call distributing
switch, the first call distributing switch coupled to a second call
distributing switch through a telephonic network, the method
comprising the steps of:
compiling data at the first call distributing switch, the compiled
data comprising identification of the first call distributing
switch, a priority level of the call assigned by the first call
distribution switch and an intended routing of the call;
transferring the data to the second call distributing switch via
the telephonic network;
transferring the call to the second call distributing switch via
the telephone network; and
processing the call at the second call distributing switch based on
the data. .Iaddend..Iadd.48. The method, as set forth in claim 47,
comprising the step of determining whether the call creates an
overflow condition.
.Iaddend..Iadd.49. The method, as set forth in claim 48, wherein
the step of compiling data comprises the step of compiling data in
response to the overflow condition. .Iaddend..Iadd.50. The method,
as set forth in claim 49, wherein the step of transferring the call
comprises the step of transferring the call in response to the
overflow condition. .Iaddend..Iadd.51. The method, as set forth in
claim 50, comprising the steps of:
selectively accepting the call by the second call distributing
switch; and
wherein the step of transferring the call comprises the step
of:
transferring the call in response to the second call distributing
switch accepting the call. .Iaddend..Iadd.52. The method, as set
forth in claim 49, wherein the step of transferring the data
comprises the step of:
transferring the data in response to the overflow condition;
and
wherein the step of transferring the call comprises the step
of:
transferring the call in response to the overflow condition with
the data. .Iaddend..Iadd.53. A call overflow system for use in an
automatic call distribution network having an originating ACD
coupled to a destination ACD through a telephonic network, the call
overflow system comprising:
means for compiling data of a call received by the originating ACD,
the compiled data including time information of the call and
information of an intended call routing at the destination ACD;
means for sending the compiled data from the originating ACD to the
destination ACD;
means at the originating ACD for transferring the call to the
destination ACD; and
means at the destination ACD for processing the call based on the
compiled
data. .Iaddend..Iadd.54. The system, as set forth in claim 53,
wherein the means for sending the compiled data comprises means for
sending the compiled data over an ISDN network. .Iaddend..Iadd.55.
The system, as set forth in claim 53, wherein the means for
compiling data compiles data of a calling party number
representative of a telephone number of the received call.
.Iaddend..Iadd.56. The system, as set forth in claim 55, wherein
the calling party number comprises an ANI number representation of
the telephone number of the received call. .Iaddend..Iadd.57. The
system, as set forth in claim 53, wherein the means for compiling
data compiles data of a called party number representative of a
telephone number dialed. .Iaddend..Iadd.58. The system, as set
forth in claim 57, wherein the called party number comprises a DNIS
number representative of the telephone number dialed.
.Iaddend..Iadd.59. The system, as set forth in claim 53, wherein
the means for compiling data compiles data identifying the
originating ACD. .Iaddend..Iadd.60. The system, as set forth in
claim 53, wherein the means for compiling data compiles data of a
priority of
the call assigned by the originating ACD. .Iaddend..Iadd.61. The
system, as set forth in claim 60, wherein the priority comprises a
priority level of the call. .Iaddend..Iadd.62. The system, as set
forth in claim 53, wherein the telephonic network comprises a
public telephonic network. .Iaddend..Iadd.63. A method for
processing a call in an automatic call distribution network having
an originating ACD coupled to a destination ACD through a
telephonic network, the method comprising the steps of:
compiling data of the call at the originating ACD, the compiled
data including time information of the call and information of a
call routing in the destination ACD;
sending the compiled data to the destination ACD over the
telephonic network;
transferring the call from the originating ACD to the destination
ACD over the telephonic network; and
processing the call at the destination ACD based on the compiled
data. .Iaddend..Iadd.64. The method, as set forth in claim 63,
wherein the step of sending the compiled data comprises the step of
sending the compiled data over an ISDN network. .Iaddend..Iadd.65.
The method, as set forth in claim 63, wherein the step of compiling
data comprises the step of compiling data of a calling party number
representative of a telephone number of the call.
.Iaddend..Iadd.66. The method, as set forth in claim 65, wherein
the step of compiling data comprises the step of compiling data of
an ANI number representation of the calling party number.
.Iaddend..Iadd.67. The method, as set forth in claim 63, wherein
the step of compiling data comprises the step of compiling data of
a called party
number representative of a telephone number dialed.
.Iaddend..Iadd.68. The method, as set forth in claim 67, wherein
the step of compiling data comprises the step of compiling data of
a DNIS number representative of the called party number.
.Iaddend..Iadd.69. The method, as set forth in claim 63, wherein
the step of compiling data comprises the step of compiling data
identifying the originating ACD. .Iaddend..Iadd.70. The method, as
set forth in claim 63, wherein the step of compiling data comprises
the step of compiling data of a priority of the call assigned by
the originating ACD. .Iaddend..Iadd.71. The method, as set forth in
claim 63, wherein the step of sending the compiled data to the
destination ACD comprises the step of sending the compiled data
over a public telephonic network to the destination ACD.
.Iaddend..Iadd.72. The method for operating a distribution network
as in claim 25 further comprising:
processing the compiled data to determine suitability of transfer
of the call to the destination switch;
optionally transferring the call from the originating switch to the
destination switch over a telephonic network after a determination
of suitability of transfer. .Iaddend..Iadd.73. The method for
processing a call as in claim 72 further comprising the step of
including ANI information as part of the compiled data.
.Iaddend..Iadd.74. The method of processing a call as in claim 72
further comprising the step of sending an alerting message to the
originating switch upon acceptance of the call by
the destination switch. .Iaddend..Iadd.75. The method of processing
the call as in claim 74 wherein the step of sending an alerting
message of acceptance of the call by the destination switch further
comprises the step of deleting a gate queue entry at the
originating switch after the destination switch answers the call.
.Iaddend..Iadd.76. The method of processing a call as in claim 72
further comprising the step of transferring the call to the
destination switch over a virtual private network type service.
.Iaddend..Iadd.77. The method of processing a call as in claim 72
wherein the step of sending the compiled data to the destination
switch further comprising the step of sending the data over a
D-channel of an integrated services digital network.
.Iaddend..Iadd.78. The method of processing a call as in claim 77
further comprising the step of transferring the call to the
destination switch over a B-channel of an integrated services
digital network. .Iaddend..Iadd.79. The method of processing the
call as in claim 72 further comprising the step of determining a
need for processing the call based upon an overflow criteria.
.Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of automatic
telephone call distribution networks and, more particularly, to
such call distribution networks in which telephonic calls are sent
from one automatic call distributor to another automatic call
distributor through a regular public external telephonic
network.
2. Description of the Related Art Including Information Disclosed
Under 37 C.F.R. Section 1.97-1.99
Automatic call distributors employing a multiport switch controlled
by a central processing unit for selectively interconnecting a
plurality of interior telephonic units with external telephonic
units received at the multiport switch through an external
telephonic network are well known. Examples of such call
distributors are shown in patent application U.S. Ser. No.
07/770,197 of Jones et al. entitled "Multichannel Telephonic
Switching Network With Different Signaling Formats and Connect/PBX
Treatment Selectable For Each Channel", filed Oct. 2, 1991, U.S.
Pat. No. 5,268,903; U.S. Pat. No. 5,140,611 of Jones et al.
entitled "Pulse Modulated Self-Clocking and Self-Synchronizing Data
Transmission and Method for a Telephonic Communication Switching
System", issued Aug. 18, 1992; U.S. Pat. No. 5,127,004 of Lenihan
et al. entitled "Tone and Announcement Message Code Generator for a
Telephonic Switching System and Method", issued Jun. 30, 1992 and
U.S. Pat. No. 4,627,047 of Pitroda et al. entitled "Integrated
Voice and Data Telecommunications Switching System", issued Dec. 2,
1986.
It is also known to send an external telephonic call received at an
automatic call distributor to another automatic call distributor in
an automatic call distribution network. Examples of such automatic
call distribution networks are shown in U.S. patent application
Ser. No. 07/960,995 of Blaha entitled "Automatic Call Distributor
With Intersubnetwork Customer Information Transfer System and
Method" filed Oct. 14, 1992.
In these known systems, a telephonic call made from an external
telephonic unit of a regular public telephone network to which the
ACD is connected, typically from a customer, is carried through the
regular, public external telephonic network to one of the plurality
of automatic call distributors (ACDs) in the private automatic call
distribution network. Once the call is received, the automatic call
distributor logically determines how the call is to be routed. The
call is often directed to an agent associated with a gate at the
originating ACD to service the call. However, it is desirable in an
ACD network having two or more call distributors to route the
telephonic call traffic as evenly as possible throughout the
network. Therefore, in many situations, a call must be transferred
or overflowed to an agent at another ACD in the private automatic
call distribution network. The agent receiving the original call
may not be able to properly service the customer at the external
telephonic unit, thus, the call must be transferred to another
agent located at another destination ACD. Moreover, the telephonic
traffic flow often exceeds the call capacity of a particular gate
at the originating ACD thereby requiring a call to be overflowed to
another trunk group or gate at another ACD in the network.
The automatic call distributors in such known systems are placed at
various distant locations throughout the network. A call
transferred between automatic call distributors is done through
dedicated trunks interconnecting the ACDs in the network.
Disadvantageously, excessive costs are associated with installing,
maintaining and operating these dedicated trunk lines between the
ACDs in private automatic call distribution network.
In such known automatic call distribution networks, the
transmission of information between automatic call distributor
nodes over costly dedicated intertandem trunks or tie lines
requires approximately a 1.0 to 1.5 second set-up signalling and
verification time between the ACD sending the overflow call and the
ACD receiving the overflow call. Thus, there is as much as a two to
three second call set up delay when overflowing a call from one ACD
to another ACD over dedicated intertandem trunks in known ACD
networks. In automatic call distribution networks servicing 1-800
or toll free calls, the user or owner of the network pays for the
cost of each call received at a call distributor.
Disadvantageously, in such known call distribution networks
receiving thousands of calls per hour, a two or three second set-up
delay per call costs the user of the network substantial amounts
each year.
Furthermore, in such known ACD networks information is sent between
ACDs across tie lines as dual tone multiple frequency (DTMF) tones.
These tones are transmitted one at a time across tie lines and
require a 160 millisecond transmission time for each tone.
Unfortunately, when twenty or thirty digits of information
transmitted as tones are desired to be sent with a call, the
transmission time is too long to efficiently transfer a call
between ACDs. Thus, only a few digits of information relating to
the overflow call are transmitted across tie lines thereby limiting
the routing and application features for the call at the receiving
ACD. Therefore, these known ACD networks provide the disadvantage
of long call set up and transfer times and further limit the amount
of digital information which can be sent with a call.
It is known to transfer a call from one automatic call distributor
to another automatic call distributor through the a regular public
external telephonic network. The Look-Ahead Interflow feature
developed by American Telephone and Telegraph Company establishes a
connection via the public external telephonic network from one ACD
to a second ACD and transfers a received call at the one ACD to the
second ACD. However, the Look-Ahead Interflow feature is limited in
the amount and type of data information which is carried with the
telephonic call to the second ACD. Look-Ahead Interflow does not
provide data to identify which gate the transferred call is to be
routed at the receiving ACD. Disadvantageously, the receiving ACD
must perform several time consuming processes in attempting to
properly route the call. Moreover, since many variable conditions
must be met at the receiving ACD to properly route the call, by not
having information identifying the gate at which the call is to be
routed increases the possibility of a call being routed to a wrong
location. Furthermore, the Look-Ahead Interflow does not identify
the original sending ACD which transfers the call to the receiving
ACD. Thus, there is nothing to prevent the inefficiency of calls
being transferred or overflowed from the destination ACD back to
the originating ACD which is not able to efficiently route the
call.
The Look-Ahead Interflow feature also fails to provide information
relating to the number of times a call has been overflowed.
Disadvantageously, calls can be continually transferred between
numerous ACDs prior to being routed to a gate and serviced by an
agent thereby increasing the amount of time to route and service an
incoming call to the network.
Furthermore, the Look-Ahead Interflow feature fails to supply the
delay time of a call in queue at the originating ACD when
transferring the call to another ACD. Consequently, the total delay
time for overflow calls cannot be ascertained. In such case, it is
not possible to accurately evaluate the overall performance of an
automatic call distribution network. For example, a call may have a
delay time of fifteen seconds at an originating ACD and an
additional five second delay after being overflowed to another or
destination ACD. In such known networks, the system administrator
at the destination ACD is only aware of the five second delay time
and not the twenty second total delay time, and thus calls at the
destination ACD are not able to be efficiently routed.
Additionally, the Look-Ahead Interflow feature disadvantageously
fails to send Automatic Number Identification (ANI) information
with an overflowed call and thus limits the information available
for the receiving or destination ACD to effectively route the
overflowed call and to trigger various optional features of the
system such as announcements, screen displays, etc.
Therefore, these known systems are limited by the limited amount of
information transferred with an overflow call, thereby reducing the
amount of routing and application features available in such
automatic call distribution network with overflow capability.
SUMMARY OF THE INVENTION
It is therefore a principal object of the present invention to
provide an automatic call distribution network with a call overflow
system in which the disadvantages of transferring a telephonic call
from one automatic call distributor to another automatic call
distributor in known call distribution networks are overcome.
This object is achieved by providing in an automatic call
distribution network having means for transferring a call received
at an originating ACD to a destination ACD through an external
telephonic network with a call overflow system, comprising means at
the originating ACD to compile data related to an overflow call to
be transmitted through the external telephonic network to the
destination ACD including at least one of the types of information
of (a) identification of a selected gate of the destination ACD to
which the call is to be routed (b) identification of the
originating ACD (c) a time information relating to a time the
overflow call was in a queue at the originating ACD (d) an ANI
number representation of a telephone number of the call received at
the originating ACD and (e) a priority level of the overflow call
and means at the originating ACD for sending the compiled data to
the destination ACD to route the overflow call at the destination
ACD.
This object is also achieved by providing in an automatic call
distribution network having an originating ACD and a destination
ACD both interrelated through an external telephonic network with a
method of transferring an overflow call comprising the steps of (1)
compiling data at the originating ACD relating to an overflow call
to be transferred through the external telephonic network to the
destination ACD including at least one of the types of information
of (a) identification of a selected gate of the destination ACD to
which the call is to be routed (b) identification of the
originating ACD (c) a time information relating to a time the
overflow call was in a queue at the originating ACD (d) an ANI
number representation of the telephone number of the call received
at the originating ACD and (e) a priority level of the overflow
call and (2) sending the compiled data from the originating to the
destination ACD to route the overflow call at the destination
ACD.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects and advantageous features of the invention
will be explained in greater detail and others will be made
apparent from the detailed description of the preferred embodiment
of the present invention which is given with reference to the
several figures of the drawing, in which:
FIG. 1 is a functional block diagram of the preferred embodiment of
the automatic call distribution network of the present invention as
interconnected with a known external telephonic network of external
telephonic units;
FIG. 2 shows the format of the preferred embodiment of the
information element data packet of the present invention; and
FIG. 3 is a flow chart of the preferred steps of transferring an
overflow call from an originating ACD to a destination ACD through
the external telephonic network in the automatic call distribution
network of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, automatic call distribution network 10 is
shown having automatic call distributors (ACDs) 12A, 12B and 12C.
Originating automatic call distributor 12A has multiport switch 14A
controlled by a central processing unit 16A in conjunction with
main memory 18A for distributing telephonic calls to internal
telephonic units 20A received from external telephonic units 22
through external telephonic network 24. The originating automatic
call distributor 12A receiving a call from a customer at an
external telephonic unit 22 routes the call to a gate 26A at which
one or more agents stationed at internal telephonic units 20A
service the call. To distribute calls received from the external
telephonic units 22 as evenly and efficiently as possible, the
originating automatic call distributor 12A transfers or overflows
received calls through the public external telephonic network 24
upon meeting a specified overflow criteria to a selected
destination automatic call distributor 12B in the ACD network
10.
The destination ACD 12B receives the overflow call sent from the
originating ACD 12A via the public network 24 at multiport switch
14B controlled by central processing unit 16B in conjunction with
main memory 18B, and routes the call to a gate 26B representing one
or more internal telephonic units 20B, if a predetermined overflow
criteria (i.e. call is idle for predetermined period of time, all
internal telephonic units for a particular gate are busy, etc.) are
met. Telephonic calls received at the originating ACD 12A and the
destination ACD 12B are routed to corresponding internal telephonic
units 20A and 29B over lines 31A and 31B, respectively. Agents
stationed at the internal telephonic units 20B of the destination
automatic call distributor 12B service the received call. If the
transferred call is not accepted at the destination ACD 12B, then
the originating ACD 12A alternatively transfers the call to another
ACD 12C specified by a system administrator at a system
administration unit 21A for servicing of the call. Preferably, the
telephonic call is prevented from being transferred back to the
originating ACD 12A when being overflowed from the destination ACD
12B. Telephonic calls are transferred through a regular public
external telephonic network 24 in utilizing a virtual private
network service type. Generally, while the telephonic call overflow
system of the present invention can be implemented in automatic
call distribution networks having a plurality of automatic call
distributors, it is preferably employed in an automatic call
distribution network having call distributors of the type shown in
patent application U.S. Ser. No. 07/770,197 of Jones et al.
entitled "Multichannel Telephonic Switching Network With Different
Signaling Formats and Connect/PBX Treatment Selectable For Each
Channel", filed Oct. 2, 1991, U.S. Pat. No. 5,268,903; U.S. Pat.
No. 5,140,611 of Jones et al. entitled "Pulse Modulated
Self-Clocking and Self-Synchronizing Data Transmission and Method
for a Telephonic Communication Switching System", issued Aug. 18,
1992; U.S. Pat. No. 5,127,004 of Lenihan et al. entitled "Tone and
Announcement Message Code Generator for a Telephonic Switching
System and Method", issued Jun. 30, 1992 and U.S. Pat. No.
4,627,047 of Pitroda et al. entitled "Integrated Voice and Data
Telecommunications Switching System", issued Dec. 2, 1986 and U.S.
patent application Ser. No. 07/960,995 of Blaha entitled "Automatic
Call Distributor With Intersubnetwork Customer Information Transfer
System and Method" filed Oct. 14, 1992.
The central processing unit 16A of the originating ACD 12A compiles
data in an information element data packet 34, FIG. 2, and sends
this data along with the overflow call to the destination ACD 12B,
FIG. 1. The data contained in the information element 34, FIG. 2,
enables the destination ACD 12B, FIG. 1, to efficiently route the
overflow call and provides information to trigger the central
processing unit 12B to perform various features at the destination
ACD 12B such as announcements of agents at internal telephonic
units 20B, announcements to customers calling from external
telephonic units 22 screen displays of data at the internal
telephonic units, prioritization of call routing and network call
handling reports. The data carried with the overflow call is shown
in greater detail in FIG. 2. Preferably, the information element
data packet 34, FIG. 2, contains the following type of information:
(1) an optional gate number for identification of a selected gate
26B of the destination ACD 12B to which the call is to be routed,
(2) the delay time of the call at the originating ACD 12A prior to
the call transfer or overflow attempt, (3) Dialed Number
Identification Service (DNIS) digits, (4) Automatic Number
Identification (ANI) digits, (5) identification data of the
originating ACD and (6) priority data of the overflow call.
Preferably, the transferring of an overflow call with the data in
the information element on the present invention is used in an
Integrated Services Digital Network (ISDN) environment. ISDN is a
worldwide telecommunication service that uses digital transmission
and switching technology to support voice and digital data
transmission. The international standards for ISDN based telephonic
equipment originated by the Comite Consultatif Internationale de
Telegraphique et Telegraphique (International Telegraph and
Telephone Consultive Committee or CCITT. The automatic call
distributors 12A, 12B and 12C of the present invention use standard
ISDN Primary Rate Interface (PRI) protocol. In North America, the
PRI provides 23 B+D signaling at 1.544 megabits per second. The "B"
stands for Bearer channel which carries 64,000 bits per second of
Pulse code modulation (PCM) digital voice or data. The "D" refers
to the Data channel which is used to carry control signals and call
information data in a packet switched mode. In the PRI, the "D"
channel runs at 64,000 bits per second and provides the signaling
information for each of the twenty-three bearer channels.
ISDN software and hardware are informally referenced to and divided
into three logical layers. Layer one is the physical layer and
provides the standards to physically interconnect telephonic
equipment of different ISDN vendors. Layer two is the data layer
and provides a software interface into layer one. Layer two handles
the transmission of data between telephone equipment and a
telephonic switching system and management of all message error
detection and correction. Layer three is the application layer in
which call control messages are generated and interpreted.
Referring to FIG. 2, the format of the preferred information
element data packet 34 is shown with the call information carried
on the "D" channel in response to the sending or overflowing of a
telephonic call from the originating ACD 12A, FIG. 1, to the
destination ACD 12B. The information element 34 is a variable
length byte data packet having eight bits per byte. The information
element data packet 34 is included as part of a SETUP message when
an overflow call is initiated between the originating switch 14A
and the destination switch 14B. The information element contains
information which the destination ACD 12B uses to route the call to
determine acceptance of the call and to trigger the sending of data
to internal telephonic units 12B servicing the overflow call.
Information identifying the information element data packet is
inserted in byte one 36, FIG. 2. The information in byte one 36
identifies to the central processing unit 16B, FIG. 1, of the
destination ACD 12B that the received data packet is an ISDN
user-to-user information element 34. The ISDN user-to-user
identifier information 36, FIG. 2, further informs the public
external telephonic network 24, FIG. 1, that the data contained in
the information element 34 concerns the private ACD network 10 and
the public external telephonic network sends the information
element data packet to the destination ACD.
Byte two 38 contains the length of the information element data
packet 34. The ISDN overflow identifier is in byte three 40. Byte
four 42 provides the gate application number. The gate application
data in byte 42 is the identification data of a selected gate 26B,
FIG. 1, of the destination ACD 12B to which the overflow call is to
be routed. A supervisor or system administrator enters a specified
gate number at a system administration unit terminal 21A to provide
the central processing unit 16A at the originating ACD 12A the
selected gate 26B at the destination ACD 12B to which an overflowed
call from a gate 26A of the originating ACD is to be routed. This
allows the system administrator at the originating ACD 12A to
determine the routing of an overflow call received at a destination
ACD 12B. In response to the receipt of the gate application number
in byte four 42 of the information element 34, FIG. 2, the central
processing unit 16B of the destination ACD 12B connects the
overflow call to a line 31B associated with the specified gate. The
overflow call is thereby serviced at an internal telephonic unit
20B associated with the identified gate 20B.
Alternatively, if no gate number 42 is specified at the originating
ACD 12A then the destination ACD 12B routes the received overflow
call as it normally routes the incoming ISDN calls from the
external telephonic network 24. The routing of an overflow call not
containing information relating to the identification of a selected
gate 26B in byte four 42 of the information element 34 is based on
DNIS digits, ANI digits or a default gate at the destination ACD.
The system administration unit 21A selectively allows or prevents
the sending of data identifying a selected gate 26B for the routing
of a call received at the destination ACD 12B from the originating
ACD. Thus, the present invention allows for flexibility in the
routing of overflow calls in that either the originating ACD 12A or
the destination ACD 12B selectively dictate how an overflow call is
routed at the destination ACD.
Bytes five and six 44, FIG. 2, contain the delay time of the call
at the originating ACD 12A. The central processing unit 16A of the
originating ACD 12A receiving the call made from an external
telephonic unit 22 maintains a record of the amount of time in
which a received call is in queue waiting to be answered at the
originating ACD. The central processing unit 16A compares the time
of receipt of a call received from an external telephonic unit 22
with the time in which the call is overflowed to determine the
delay time in queue for the call. The delay time of the calling
party from the external telephonic unit is carried in the
information element data packet 34 with an overflow call
transferred from the originating ACD 12A to the destination ACD
12B. The delay time information received at the destination ACD 12B
is used to evaluate the call handling performance throughout the
ACD network 10. The central processing unit 16B at the destination
ACD 12B determines a total delay time of the overflow call by
adding the delay time data received in the information element 34,
FIG. 2, with the delay time the call is in queue at the destination
ACD. Preferably, the central processing unit 16B at the destination
ACD 12B routes calls having a longer delay time in queue to an
internal telephonic unit 20B before another call having a shorter
delay time.
Various types of telephonic calls, such as 1-900 and 1-800 or
toll-free calls, received from the external telephonic units 22,
FIG. 1, frequently are assigned call type identification signals
which are transferred with the call to the originating ACD 12A
originally receiving the call. These call type identification
signals preferably are Dialed Number Identification Service (DNIS)
digits or Automatic Number Identification (ANI) digits which are
associated with different types of calls. Specifically, it is
common practice for a long distance telephone carrier company of
the public external telephonic network 24 to assign DNIS digits or
ANI digits associated with different types of telephonic calls.
Examples of such long distance carrier companies are American
Telephone and Telegraph Co., MCI, Sprint, etc. The DNIS digits or
ANI digits, or both, are carried concurrently with the telephonic
call from the external telephonic network 24 to the originating ACD
12A. The DNIS digits or ANI digits, or both, are further carried
with the telephonic call which is overflowed from the originating
ACD 12A originally receiving the call to the destination ACD 12B
receiving the overflow call.
The DNIS digits of the originating call received from an external
telephonic unit 22, FIG. 1, are located in bytes seven and eight
46, FIG. 2. Byte nine 48 of the information element 34 contains the
data for the total number of ANI digits associated with the
particular type of overflow call being sent to the destination ACD
12B. Bytes nine A through nine E 50 contain the ANI digits which
represent the telephone number of the external telephonic unit 22
generating a call received at the originating ACD 12A and
transferred as an overflow call to the destination ACD 12B. The ANI
digits 50 are carried in the information element data packet 34
with the overflow call from the originating switch 14A and received
at the destination switch 14B. The central processing unit 16B at
the destination ACD 12B selectively uses the digital ANI
information 50 for routing of the received overflow call to a
designated gate 26B and in turn, to an internal telephonic unit 20B
to service the call. The ANI information received at the
destination ACD 12B also triggers the central processing unit 16B
to send information and execute various applications at the
internal telephonic units 20B. These applications include but are
not limited to the playing of personal announcements regarding the
type of incoming call to agents stationed at the internal
telephonic units, displaying data regarding the call at agent
terminals at the internal telephonic units and playing recorded
messages to customers calling form the external telephonic
unit.
Information regarding the identification of the site of the
originating ACD 12A, FIG. 1, is located in byte ten 52, FIG. 2 of
the information element data packet 34. The data identifying the
originating ACD 12A in byte ten 52 informs the central processing
unit 16B of the destination ACD 12B as to the location of the
automatic call distributor in the network 10 which transferred the
overflow call. In response to receipt of the originating ACD site
identification data 52, the central processing unit 16B of the
destination ACD determines the origin of the received overflow
call. The originating ACD site information 52 is used by the
central processing unit 16B of the destination ACD 12B to track
data relating to the call received at the originating ACD 12A. The
information identifying the originating ACD is particularly useful
in an ACD Network 10 in which data is accessed from a common data
base by the originating ACD 12A and the destination ACD 12B.
Byte twelve 56 contains information regarding the priority of the
overflow call. Calls from the external telephonic units 22 of the
external network 24 received at the originating ACD 12A are
categorized into different priority levels. The system
administrator at the system administration unit 21A inserts into
the memory 18A of the originating ACD 12A the various priority
levels for various calls received at the switch 14A. Preferably,
calls assigned to higher priority levels are routed to internal
telephonic units sooner than calls having a lower priority level.
The priority level assigned to a particular call is inserted into
byte twelve 56, FIG. 2, of the information element 34 in response
to the call being overflowed to a destination ACD 12B. The assigned
priority level 56 of the overflow call informs the destination ACD
12B of the categorized priority level of the call. The central
processing unit 16B places the received call in the appropriate
level within a queue to properly service the overflow call at the
destination ACD 12B. The call information in the data packet 34
allows for flexibility in routing and efficient management of the
call distribution in the ACD network 10.
Referring again to FIG. 1, the implementation of ISDN standards
ensures the sending of telephonic calls with associated call
information between multiple ACDs 12A, 12B and 12C using PRI
D-channels and B-channels through the public external telephonic
network 24. This provides for a call overflow system 32 without the
cost of dedicated D-channels and B-channels over tie lines between
the call distributors. The use of ISDN messages to overflow a call
allows specific information associated with the call to be sent
from the originating ACD 12A to the destination ACD 12B.
A telephonic call is received at the switch 14A of the originating
ACD 12A from an external telephonic unit 22 through the public
network 24. The central processing unit 16A determines which gate
26A the call is to be routed. The memory 18A of the central
processing unit 16A contains the predetermined criteria used for
determining the overflow of a call to a destination ACD 12B. In
response to the predetermined overflow criteria being met for a
gate 26A at the originating ACD 12A an ISDN route is used to select
an idle ISDN B-channel utilizing a T-1 span line 28 to carry the
call through the public external telephonic network 24. The central
processing unit 16A of the originating ACD 12A allocates an ISDN
B-channel on the T-1 span line 28 for the transferring of the
overflow call to the destination ACD 12B. The call received at the
originating multiport switch 14A is selected for overflow to the
destination multiport switch 14B of the destination ACD 12B.
Once an ISDN B-channel is selected for overflow and the received
telephonic call at the originating ACD 12A awaiting answer by a
gate server or internal telephonic unit 20A is selected for
overflow service, the originating ACD sends a SETUP message over a
D-channel across T-1 span line 28 to the public external telephonic
network 24 and through trunk line T-1 span line 30 to a specified
destination ACD 12B. A gate server or internal telephonic unit 20A
is a device capable of answering a call directed to an associated
gate 26A. The gate server devices are assigned to a gate 26A
through primary, secondary or tertiary assignments. Preferably,
gate servers 20A, 20B include but are not limited to: agent
telephonic units in which agents service received calls, voice
response units, automatic response units and gate private branch
exchanges. The SETUP message is an ISDN layer three message used to
indicate call establishment. The SETUP message contains the
information element data packet 34, FIG. 2, providing the specific
call routing and feature triggering information associated with the
overflow call to the destination ACD 12B, FIG. 1.
When the destination ACD 12B receives the SETUP message, the
receipt of the accompanying information element data packet 34,
FIG. 2, serves as an indication that the call received is a call
transferred or overflowed from another ACD in the ACD network 10.
In response to the receipt of the data in the information element
34, the central processing unit 14B of the destination ACD 12B
determines how to route the received overflow call. Preferably, the
order of precedence for routing the call at the destination ACD 12B
is as follows:
1. If a gate number 42, FIG. 2, is carried with the information
element data packet 34, the destination ACD 12B, FIG. 1, routes the
call to the identified gate 26B.
2. If a gate number 42, FIG. 2, is not supplied in the information
element 34, then the destination ACD 12B, FIG. 1, attempts to route
the call based upon the DNIS 46 or ANI numbers 50 in the
information element data packet 34. If neither DNIS nor ANI are
supplied, then default routing is performed. If the DNIS number 46
is invalid, DNIS default gate routing, if implemented, is
performed. If the DNIS number 46 is invalid and DNIS default gate
routing is not implemented, the overflow call is rejected.
3. If a gate number 42 is not supplied to the information element
34 and no DNIS number 46 appears in the information element data
packet, but an ANI number 50 does appear in the information
element, then the call is routed based on its associated ANI
number. The ANI and DNIS numbers contained in the information
element 34 are used for other features requiring ANI or DNIS
information.
If the destination ACD 12B, FIG. 1, accepts the call, an ALERTing
message is sent to the originating ACD 12A. The originating ACD 12A
logs an Overflow Outcall Accepted in the Gate Overflow and Trunk
information-Group records in its associated memory 18A.
When a gate server or internal telephonic unit 20B at the
destination ACD 12B answers the call, a CONNect message is
propagated to the originating ACD 12A. The gate queue entry is
deleted and connected to the outgoing B-channel selected for the
overflow. The caller at the external telephonic unit 22 and the
gate server 20B have a two-way connection, and the overflow attempt
is successfully completed. An overflow out-call handled is logged
in the gate overflow record at the originating ACD memory 18A,
while an overflow in-call handled is logged in the trunk
information-group and gate records at the destination ACD memory
18B. An ISDN overflow in-call handled and delay time to overflow
for handled calls are also logged in the destination ACD memory
18B.
While the advantages of the invention are preferably obtained in
the automatic call distribution network 10 described above with
reference to FIG. 1, the method can be practiced with any other
automatic call distribution networks having means for transferring
a call received at an originating automatic call distributor (ACD)
to a destination automatic call distributor through an external
telephonic network. In any event, the preferred method of
practicing the invention comprises the steps of (1) compiling data
at the originating ACD relating to an overflow call through the
external telephonic network to the destination ACD including at
least one of the types of information of (a) identification of a
selected gate of the destination ACD to which the call is to be
routed (b) identification of the originating ACD (c) a time
relating to a time the overflow call was in a queue at the
originating ACD (d) an ANI number representation of a telephone
number of the call received at the originating ACD and (e) a
priority level of the overflow call; and (2) sending the compiled
data from the originating to the destination ACD to route the
overflow call at the destination ACD.
Referring to FIG. 3, the method of overflowing a call from an
originating ACD 12A to a destination ACD 12B via the public
external telephonic network 24 is done in the call overflow system
32 at step 100 by the originating ACD receiving a telephonic call
from an external telephonic unit 22, FIG. 1, through the external
telephonic network. In step 102, FIG. 3, the central processing
unit 16A, FIG. 1, for the originating ACD 12A receiving the call
from the external telephonic unit 22 determines if the overflow
criteria have been met for a gate 26A at the originating ACD. While
determining if the overflow criteria have been met, the originating
ACD 12A also selects an ISDN route on a trunk line 28 and an
attempt is made to allocate an ISDN B-channel for the overflow
call. If the overflow criteria is not met, in step 104, FIG. 3, the
central processing unit 16B attempts another overflow after 500
milliseconds. If the overflow criteria are met, then in step 106
the originating ACD 12A selects a telephonic call in the queue for
the specified gate 26A, FIG. 1, for transfer to the destination ACD
12B. If a telephonic call is not selected for overflow to the
multiport switch 14B of the destination ACD 12B, then the
originating ACD 12A repeatedly attempts to overflow a call every
500 milliseconds in step 104, FIG. 3. If the telephonic call
received at the originating ACD 12A is selected for overflow, then
in step 108 the originating ACD transmits a SETUP message
containing the information element data packet 34, FIG. 2, to the
destination ACD 12B via the public external telephonic network 24.
The telephonic call is selected for overflow to a destination ACD
12B based on the criteria set for establishing overflow calls.
Preferably, the criteria as based on the delay time of calls
received from an external telephonic unit that is placed in a queue
at the originating ACD 12A along with the number of calls currently
overflowed and accepted to a destination ACD 12B.
In step 106, FIG. 3, once the originating ACD 12A, FIG. 1, selects
an ISDN B-channel for the overflow of the call to the destination
ACD 12B and the telephonic call awaiting answer by a gate server
20A is selected for overflow service, the originating ACD 12A sends
a SETUP message in step 108 over a D-channel, through the public
network 24 to a specified destination ACD 12B. The information
element 34, FIG. 2, received at the destination ACD 12B, FIG. 1, as
part of the SETUP message serves as an indication to the
destination ACD 12B that the received call is an overflow call
transferred from an originating ACD 12A as opposed to a call
directly connected through the public network 24 from an external
telephonic unit 22, FIG. 1.
In step 110, FIG. 3, the destination ACD 12B receives the SETUP
message with the information element data packet 34, FIG. 2. In
step 116, the destination ACD 12B determines if a call can be
accepted. The central processing unit 16B of the destination ACD
12B determines the acceptance of the overflow call based on
acceptance criteria which are (1) the call time in queue, in that
the maximum delay in queue is greater than a specified threshold
criteria, and (2) if the number of accepted overflow calls is less
than the specified call limit, then the overflow call is accepted
at the destination ACD. If a call cannot be accepted, then in step
118, FIG. 3, the destination ACD 12B, FIG. 1, sends a RELease
COMPlete message through the public network 24 to the originating
ACD 12A. The RELease COMPlete message is an ISDN layer three
message which indicates that the destination ACD 12B released the
B-channel and call reference and the B-channel is available for
use. In step 120, FIG. 3, the originating ACD 12A receives the
RELease COMPlete message and the telephonic call is placed back in
queue at the originating ACD.
If the telephonic call is accepted at the destination ACD 12B, then
in step 122, the destination ACD responds by sending an ALERTing
message to the originating ACD 12A in step 124 and inserts the call
in the queue for the specified gate 26B at the destination ACD. The
ALERTing message is an ISDN layer three message sent by the
destination ACD 12B to the public network 24 and by the public
network to indicate that a called user alerting has been initiated.
In step 126, the overflow call to the destination ACD 12B is logged
as "accepted" at the originating ACD 12A. In step 128, an agent at
an internal telephonic unit 20B, FIG. 1, of the destination ACD 12B
answers the overflow call and the destination ACD 12B sends a
CONNect message to the originating ACD 12A. A CONNect message is an
ISDN layer three message indicating the answer of a call by an ACD.
The CONNect message is sent from the destination ACD 12B in step
130 through the public external telephonic network 24 to the
originating ACD 12A. In step 132, the originating ACD 12A connects
the telephonic call from the external telephonic unit 22, FIG. 1,
to an outgoing ISDN B-channel.
In step 134, the originating ACD 12A sends a CONNect ACKnowledge
message to the public external telephonic network 24 to confirm the
internal telephonic unit 20B has received the connected call. A
CONNect ACKnowledge message is an ISDN layer three message sent by
the ACD network 10 to the external telephonic unit 22 via the
public external telephonic network 24 to confirm that the internal
telephonic unit 20B has received the connected call. In response to
the receipt of the CONNect message, a two way voice communication
path is established in step 136, FIG. 3, between the caller at the
external telephonic unit 22 and the internal telephonic unit 20B at
the destination ACD 12B via the originating ACD 12A and the public
external telephonic network 24. While the flow chart of FIG. 3
illustrates the process of completing an overflow call with the
associated information element data packet between the originating
ACD and the destination ACD, the same procedural steps are
implemented upon transferring an overflow call again from the
originating ACD to any number of other ACDs in the automatic call
distribution network.
While a detailed description of the preferred embodiment of the
invention has been given, it should be appreciated that many
variations can be made thereto without departing from the scope of
the invention as set forth in the appended claims.
* * * * *