U.S. patent number 6,128,304 [Application Number 09/178,130] was granted by the patent office on 2000-10-03 for network presence for a communications system operating over a computer network.
This patent grant is currently assigned to GTE Laboratories Incorporated. Invention is credited to Thomas James Antell, Rajiv Bhatnagar, Steven E. Gardell, Barbara Mayne Kelly, Israel B. Zibman.
United States Patent |
6,128,304 |
Gardell , et al. |
October 3, 2000 |
Network presence for a communications system operating over a
computer network
Abstract
A method and apparatus are implemented for providing traditional
telecommunications service capabilities in a packet based computer
network. The system and method of the present invention
automatically provide such service capabilities in the event a
terminal end-point is unavailable to receive an incoming call,
based upon predetermined associations between the terminal
end-point and one or more of the available services.
Inventors: |
Gardell; Steven E. (North
Andover, MA), Kelly; Barbara Mayne (Concord, MA),
Bhatnagar; Rajiv (Acton, MA), Antell; Thomas James
(Westford, MA), Zibman; Israel B. (Newton, MA) |
Assignee: |
GTE Laboratories Incorporated
(Waltham, MA)
|
Family
ID: |
22651328 |
Appl.
No.: |
09/178,130 |
Filed: |
October 23, 1998 |
Current U.S.
Class: |
370/401; 370/260;
370/352; 379/202.01 |
Current CPC
Class: |
H04L
12/64 (20130101); H04L 29/06 (20130101); H04L
29/06027 (20130101); H04M 7/0075 (20130101); H04L
65/1009 (20130101); H04L 65/1096 (20130101); H04L
67/327 (20130101); H04M 2207/203 (20130101); H04L
69/329 (20130101) |
Current International
Class: |
H04L
12/64 (20060101); H04L 29/06 (20060101); H04M
7/00 (20060101); H04L 29/08 (20060101); H04M
001/64 () |
Field of
Search: |
;370/259,260,261,270,352,355,356,401 ;379/201,202,211,212 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
5768346 |
December 1999 |
Spruijt |
5999525 |
December 1999 |
Krishnaswamy et al. |
|
Foreign Patent Documents
Other References
Thom, "H.323: The Multimedia Communications Standard for Local Area
Network", IEEE, pp. 52-56, Dec. 1996. .
Labriola, Don, "Here's Looking at You," Computer Shopper, Sep.
1997, pp. 335-362. .
Kahane, Opher et al., Call Management Agent System: Requirements,
Function, Architecture and Protocol, IMTC VoIP Forum Contribution,
Jan. 15, 1997, 44 pages..
|
Primary Examiner: Pham; Chi H.
Assistant Examiner: Duong; Frank
Attorney, Agent or Firm: Suchyta; Leonard Charles Anderson;
Floyd E.
Parent Case Text
RELATED APPLICATIONS FLED CONCURRENTLY HEREWITH
This invention is related to the following inventions, all of which
are filed concurrently herewith and assigned to the assignee of the
rights in the present invention: Ser. No. 60/105,326 of Gardell et
al. entitled "A HIGH SPEED COMMUNICATIONS SYSTEM OPERATING OVER A
COMPUTER NETWORK"; Ser. No. 09/177,712 of Gardell et al. entitled
"MULTI-LINE TELEPHONY VIA NETWORK GATEWAYS"; Ser. No. 09/178,271 of
Gardell et al. entitled "SPEAKER IDENTIFIER FOR MULTI-PARTY
CONFERENCE"; Ser. No. 09/178,178 of Gardell et al. entitled "SYSTEM
PROVIDING INTEGRATED SERVICES OVER A COMPUTER NETWORK"; Ser. No.
09177,415 of Gardell et al. entitled "REAL-TIME VOICEMAIL
MONITORING AND CALL CONTROL"; Ser. No. 09/177,700 of Gardell et al.
entitled "MULTI-LINE APPEARANCE TELEPHONY VIA A COMPUTER NETWORK";
and Ser. No. 09/177,712 of Gardell et al. entitled "MULTI-LINE
TELEPHONY VIA NETWORK GATEWAYS".
Claims
We claim:
1. A communication system for interacting with a switched circuit
network and for providing network-based services for handling
incoming calls directed to at least one terminal end-point, the
system comprising:
a gateway in communication with the switched circuit network, the
gateway being operative to translate switched circuit
network-compatible signals into computer network-compatible
signals;
an association table configured to store a routing address
corresponding to the terminal end-point, the routing address
identifying a preselected one of the terminal end-point and a
network-resident service terminal;
a signal routing agent in communication with the gateway, with the
terminal end-point, and with one or more network-resident service
terminals, the signal routing agent being operative to receive an
incoming call from the gateway addressed to the terminal end-point;
and
a feature selector in communication with the signal routing agent
and the association table, the feature selector being programmed to
determine a routing address for the incoming call using the
association table and to instruct the signal routing agent to route
the incoming call based on the routine address.
2. The system of claim 1, wherein:
the signal routing agent is programmed to notify the feature
selector upon receipt of the incoming call.
3. The system of claim 1 wherein:
the feature selector is responsive to receipt of an incoming call
addressed to one of the terminal end-points to access the
association table to identify one of the network-resident service
terminals to receive the incoming call, and to signal the signal
routing agent to route the incoming call to the identified
network-resident service terminal.
4. The system of claim 1 wherein:
the gateway and signal routing agent are constructed to operate
under an H.323 standard.
5. The system of claim 1 wherein:
the signal routing agent comprises a call routed gatekeeper.
6. The system of claim 1 wherein:
the signal routing agent comprises a call control service
entity.
7. The system of claim 6 wherein:
the call control service entity comprises the feature selector and
the association table.
8. A system for use in a packet based network, the packet based
network including one or more terminal end-points and one or more
network-resident service nodes, the system comprising:
a call management database configured to store a routing address
corresponding to each of the terminal end-points, the routing
address identifying a preselected one of the corresponding terminal
end-points and one of the service nodes;
a service feature selector programmed to access the call management
database upon notification of an incoming signal directed to one of
the terminal end-points to determine a destination to receive the
incoming signal based on routing address; and
a signal routing agent in communication with the service feature
selector, the signal routing agent being operative to receive
incoming signals and to route the incoming signals to appropriate
destinations as directed by the service feature selector.
9. The system of claim 8 wherein:
the service feature selector is further programmed to access the
call management database to identify one of the service nodes for a
terminal end-point in the event the terminal end-point is
unavailable.
10. The system of claim 8 wherein:
the signal routing agent is responsive to receipt of an incoming
signal to notify the service feature selector; and
the service feature selector is responsive to receipt of the
notification to access the call management database to determine
the appropriate destination to receive the incoming signal.
11. The system of claim 8 wherein:
the signal routing agent comprises a call control service
entity.
12. The system of claim 11 wherein:
the call control service entity comprises the service feature
selector and the call management database.
13. The system of claim 8 wherein:
the signal routing agent comprises a call routed gatekeeper.
14. The system of claim 8 wherein:
the call management database is in the form of an association
table.
15. The system of claim 8 wherein:
the signal routing agent is constructed to operate under an H.323
standard.
16. A method for providing network-resident communication services
in a packet based network, comprising the steps of:
receiving an incoming call addressed to a particular terminal
end-point in the packet based network;
determining whether to send the incoming call to the terminal
end-point or one of a plurality of network-resident service nodes
based on predetermined data;
sending the incoming call to the network-resident service node when
the predetermined data identifies the network-resident service
node;
sending the incoming call to the terminal end-point when the
predetermined data identifies the terminal end-point;
determining whether the terminal end-point is available to receive
the incoming call;
if the terminal end-point is not available, identifying one of the
network-resident service nodes to receive the incoming call;
and
routing the incoming call to the identified network-resident
service node.
17. The method of claim 16 wherein the step of determining whether
the
terminal end-point is available comprises routing the incoming call
to the terminal end-point and monitoring whether the terminal
end-point responds to the incoming call within a preselected time
period.
18. The method of claim 16 wherein the step of determining whether
to send the incoming call to the terminal end-point or the
network-resident service node comprises accessing a call management
database to check if the network-resident service node has been
selected to receive incoming calls directed to the terminal
end-point.
19. A method for providing network-resident communication services
in a packet based network, comprising the steps of:
receiving an incoming call addressed to a particular terminal
end-point;
accessing a call management database to determine whether the
terminal end-point is linked with a corresponding service node for
initial call presentation;
if the terminal end-point is linked with the service node for
initial call presentation, routing the incoming call to the service
node; and
if no service node is linked with the terminal end-point, routing
the incoming call to the terminal end-point.
20. The method of claim 19 and further including the steps of:
after the incoming call has been routed to the terminal end-point,
determining whether the terminal end-point is unavailable;
if the terminal end-point is unavailable, accessing the call
management database to determine the appropriate service node to
receive the incoming call; and
routing the incoming call to the appropriate service node.
21. The method of claim 20 wherein the step of determining whether
the terminal end-point is available comprises monitoring whether
the terminal end-point responds to the incoming call within a
selected period of time.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to the field of
telecommunications. More specifically, the invention is directed to
a method and apparatus for providing a network-based presence in an
H.323-based communications system to handle one or more incoming
calls and to provide various services in instances where the called
parties are unavailable.
2. Description of the Related Art
H.323 is an International Telecommunications Union (ITU) standard
that provides guidelines for terminals and equipment that provide
multimedia communications services over packet-based computer
networks (PBNs). H.323 terminals and equipment may carry real-time
audio, video and/or data.
The packet based network over which H.323 terminals communicate may
be a point-to-point connection, a single network segment, or an
inter-network having, multiple segments with complex topologies,
such as local area networks (LANs), Intra-Networks, and
Inter-Networks, including the Internet.
H.323 terminals may be used in point-to-point, multi-point, or
broadcast configurations (as described in H.332). They may
interwork with H.310 terminals on B-ISDN, H.320 terminals on
N-ISDN, H.321 terminals on B-ISDN, H.322 terminals on Guaranteed
Quality of Service LANs, H.324 terminals on GSTN and wireless
networks, V.70 terminals on GSTN, and voice terminals on GSTN or
ISDN through the use of Gateways. H.323 terminals may be integrated
into personal computers or implemented in stand-alone devices such
as video telephones.
Computer networks which are capable of transmitting data or
information between locations, such as the above-mentioned
Internet, have been used to transmit audio information between
computers without incorporating H.323-based communications systems.
At the transmitting computer, a person's voice may be digitized
using a conventional analog to digital (A/D) converter and
transmitted to the receiving location where it is passed through a
conventional digital to analog (D/A) converter and presented as
audio. This type of audio connectivity is somewhat similar to flat
rate telephony, in that audio information may be transmitted from
one location to another by way of a high bandwidth, flat rate
communications medium.
This type of computer telephony system suffers from several major
disadvantages. First, the system is limited to only those people
who have access to the Internet and who are using compatible
end-point software. In addition, while Internet access has now
widely proliferated, it has not reached the near universal
accessibility of traditional telephone service over public switched
telephone networks (PSTNs) and the like. Thus, such a computer
telephony system is totally useless if a user on the Internet
desires to communicate with someone who does not have access to the
Internet.
On the other hand, an H.323-based communications system allows
people on a computer network, such as the Internet, to communicate
with people on a conventional telephone network, such as a PSTN,
general switched telephone network (GSTN), integrated services
digital network (ISDN), or other switched circuit network (SCN).
Such a system provides the appropriate translation between SCN and
PBN data formats and between different communication procedures, in
order to allow a user on one system (such as the PSTN) to
communicate with a user on an otherwise incompatible system (such
as a packet based network).
While H.323-based communications systems effectively support
communication between two otherwise incompatible networks, current
use of those systems has been somewhat limited. Current systems are
designed to support communication between two parties, and also
provide for conferencing of multiple parties in a single call.
However, H.323-based systems do not presently address the provision
of more traditional phone behavior offered in PSTN and other
conventional telecommunications networks. This is a significant
drawback, especially for those who are already reluctant to convert
from conventional telecommunications networks to an H.323-based
system for their telecommunications needs.
As an example, one shortcoming associated with current H.323-based
communications systems is that there is no procedure for connecting
an incoming call with a network-based service such as voicemail
when a called party's terminal is off-line. Existing H.323 systems
provide services such as call forwarding and voice mail; however,
these services are implemented solely at the terminal end-point
being called. Thus, if the party's terminal is off-line, these
services are simply unavailable, and the call cannot be
completed.
Accordingly, there continues to be a need for a communications
system that provides for communication between a packet based
network (PBN) and a conventional switched circuit network (SCN),
while simultaneously providing various services for handling an
incoming call in the event the called party is unavailable, whether
or not that party's terminal is on-line. The present invention
addresses these needs and others.
SUMMARY OF THE INVENTION
According to the present invention, a novel system and method are
described which provide various telecommunications service
capabilities on a computer network in instances where the called
party is unavailable, regardless of the status of the called
party's terminal. The invention is operative to route such calls to
various service nodes offering well known services, including
traditional voice mail, personal assistant, and call forwarding
services. The present invention is incorporated in a network-based
system to support communication with conventional SCNs. The
network-based system includes a gateway that provides for
communication between two dissimilar networks, a signal routing
agent that controls operation and transmits signals, and one or
more service nodes to
selectively receive incoming calls and provide various
services.
Thus, the present invention in one preferred embodiment is directed
to a communication system for interacting with a switched circuit
network and for establishing a network presence to, under
predetermined conditions, provide network-based services for
handling incoming calls directed to a terminal end-point, the
system comprising: a gateway in communication with the switched
circuit network, the gateway being operative to translate switched
circuit network-compatible signals into computer network-compatible
signals; a signal routing agent in communication with the gateway,
with the terminal end-point, and with one or more network-resident
service entities, the signal routing agent being operative to
receive an incoming call from the gateway addressed to the terminal
end-point and to transmit the incoming call to the terminal
end-point; and a feature selector in communication with the signal
routing agent, the feature selector being programmed to, under the
predetermined conditions, determine a corresponding service entity
for the terminal end-point being called and to transmit a
corresponding signal to the signal routing agent, whereby the
signal routing agent is responsive to receipt of the signal from
the feature selector to route the incoming call to the
corresponding service entity.
In another preferred embodiment, the present invention comprises: a
call management database storing service information for one or
more terminal end-points; a service feature selector programmed to
access the call management database under predetermined conditions
to determine an appropriate service node to receive an incoming
call; and a signal routing agent in communication with the service
feature selector and with the gateway, the signal routing agent
being operative to receive incoming calls from a gateway and to
route the incoming calls to the appropriate service nodes as
directed by the service feature selector.
A preferred method of the present invention includes the steps of:
receiving an incoming call addressed to a particular terminal
end-point; determining whether the terminal end-point is available
to receive the incoming call; if the terminal end-point is not
available, determining an appropriate network-resident service node
to receive the call; and routing the incoming call to the
appropriate network-resident service node.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention discussed
in the above summary of the invention will be more clearly
understood when taken together with the following detailed
description of preferred embodiments which will be understood as
being illustrative only, and the accompanying drawings reflecting
aspects of those embodiments, in which:
FIG. 1 is a block diagram of an H.323-based communications system
comprising one preferred embodiment of the present invention;
FIG. 2 is a block diagram showing a call control service entity and
service node included in the system of FIG. 1;
FIG. 3 is a schematic diagram of a call management database
generated and maintained by the system of FIG. 1;
FIG. 4 is a block diagram of an alternative embodiment of the
system of the present invention;
FIG. 5 is a timing diagram for the signaling sequence of the system
of FIG. 4; and
FIG. 6 is a flow chart depicting the operational flow of the
systems of FIGS. 1 and 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following detailed description, like reference numerals will
be used to refer to like or corresponding elements in the different
figures of the drawings. Referring now to the drawings, and
particularly to FIG. 1, there is shown an H.323-based network
system 10 comprising a preferred embodiment of the invention.
Generally, the network system includes a gateway 12, a gatekeeper
14, a signal routing device, for example a call control service
entity 16 (CCSE), one or more network-resident service nodes 18,
and plural terminal end-points 20. In the preferred embodiment, the
network system 10 is operative to receive plural incoming calls
from, for example, a public switched telephone network 22 (PSTN)
that seek to establish communication with one or more of the
terminal end-points, determine whether the terminal end-point or
end-points are available and, if one or more of the end-points are
unavailable, route the corresponding incoming calls to a
preselected network-resident end-point 20.
The gateway 12 comprises an H.323-defined entity, and provides
signal conversion capabilities between a switched public network,
for example the PSTN 22, and the H.323-based network to support
communication therebetween. The gateway also allows for
interworking with other H-series terminals, GSTN or ISDN voice
terminals, or GSTN or ISDN data terminals. The gateway is operative
to accept a call originating on, for example, the PSTN 22, to
convert the signal to an H.323-compatible format, and to pass it
into the H.323 network. The gateway may also perform the opposite
function, namely take a call originating in H.323, convert the
signal to a PSTN-compatible format, and pass it on to the PSTN 22.
The gateway is responsible for passing caller-ID data,
number-dialed data, and other such information in both directions.
Various telephony signaling technologies may be used by the gateway
to perform these functions, as are well known to those of ordinary
skill in the art.
The gatekeeper 14 is also an H.323-defined component that provides
admissions control and address translation services. In addition,
the gatekeeper may also be configured to provide call control
services and route call control signals to the H.323 terminal
end-points 20. The gatekeeper is in communication with the gateway,
and initially receives a translated phone number dialed by a caller
on the PSTN 22, such as an E.164 address, from the gateway. The
gatekeeper accesses a translation table (not shown) to determine
the corresponding IP address of the terminal end-point, and
coordinates initial call presentation procedures, as described in
greater detail below.
The gatekeeper 14 typically includes a server in the form of a
computer or router that is dedicated to running the gatekeeper. The
computer or router is programmed with software to provide H.323
specified gatekeeper functionality.
The CCSE 16 comprises a signal routing agent, and is responsible
for attempting to connect a caller with a particular terminal
end-point 20. The CCSE is signaled by the gatekeeper 14 with the
address of the appropriate terminal end-point for receiving the
call. The CCSE then routes a call setup signal to the terminal
end-point, as is described in greater detail below. In place of the
CCSE 16, a call routed gatekeeper could be used to provide the call
control services for the network 10. In that event, the gatekeeper
would process the call signaling itself and complete the call
signaling with the terminal end-point or end-points.
Referring to FIG. 2, in one illustrative embodiment of the present
invention, the CCSE 16 includes a feature selector 24, a call
management database 26, a signal routing device 30, and H.323
stacks 32. In the event a called terminal end-point 20 is
determined to be unavailable, the feature selector is programmed to
access the call management database 26 to determine the proper
end-point 20 to receive the incoming call, as is described in
greater detail below. The signal routing device 30 is responsible
for routing an incoming call received from the gateway to a
corresponding terminal end-point 20, as is well known in the
art.
While the feature selector 24 is shown in one preferred embodiment
as being contained within the CCSE 16, it will be apparent that the
feature selector can be a separate entity that is connected for
two-way communication with the CCSE. The CCSE, after determining
that a terminal end-point is unavailable, transmits a corresponding
signal to the feature selector that identifies the terminal
end-point being called and alerts the feature selector that the
terminal end-point is unavailable. The feature selector then
accesses the call management database 26, determines the
appropriate end-point 20 to receive the call, and transmits a
corresponding signal back to the CCSE with the appropriate output
parameters such as the address of the end-point 20 to receive the
call. This signaling between the CCSE and feature selector can be
done through the use of call-backs, or any other similar
manner.
The call management database 26 is preferably in the form of a pair
of association or look-up tables 27 and 28 (FIG. 3). The
association tables comprise plural address lines 29, each of which
provides a segment to link a terminal end-point with a
corresponding network-resident service node 18. In the embodiment
shown, the first association table 27 defines an initial call
presentation table and provides links for each terminal end-point
to appropriate end-points, whether they are to the end-point 20
itself or to a service node 18. The second association table 28
defines an unavailable terminal table, and provides links for each
terminal end-point to the appropriate service node. Thus, the first
association table is preferably accessed before an incoming call is
routed to the corresponding terminal end-point 20 to determine
whether a service node has been selected to receive all incoming
calls directed to that terminal end-point. For example, the user at
the terminal end-point may select to temporarily have all incoming
calls routed to one of the service nodes so that he or she is not
disturbed. Thus, the first table is dynamic and will change often.
The second table is preferably accessed only after a call has been
presented to a terminal end-point, and the terminal end-point fails
to connect with the call within a predetermined period of time.
As shown in FIG. 3 as an example, the terminal end-point T1 is
linked in the first association table 27 with the voice mail
platform of the service node 18. As such, until that association
for T1 is changed, all incoming calls directed to T1 are routed
directly to the voice mail platform of the service node, and are
not presented at the terminal T1 itself. T1 is also linked in the
second association table 28 with the voice mail platform of the
service node. Thus, once the association in the first association
table is changed for T1, any calls presented to T1 that are not
answered within a predetermined period of time will be routed to
the voicemail platform of the service node 18.
As shown in FIG. 3, the first association table 27 does not link
terminal end-point T2 with any service node, but rather with
itself. Thus, incoming calls for T2 are routed to T2 and are
initially presented there. The second association table 28 links T2
with the voice mail platform of the service node 18. Thus, any
calls presented to T2 that are not accepted by T2 within some
preselected period of time are routed to voice mail. Similarly,
calls to T3 will be routed to T3 and, if not answered, will be
routed to a personal assistant subsystem of the service node, as
dictated by the associations for T3.
The entries in the first association table 27 are dynamic and may
be changed frequently. For example, when a user at a terminal is
about go off-line, he or she may select to have all incoming calls
routed to a personal assistant service node, a call forwarding
service node, or other well known type of service node. Such
information is received by the CCSE and is stored in the
appropriate field in the first association table 27. When the user
is back on-line, he or she may select to be presented with all
incoming calls. This information is received by the CCSE, which
updates the appropriate field in the first association table.
While in the embodiment disclosed there are two discrete
association tables 27 and 28, it will be understood by those of
ordinary skill in the art that one association table may
alternatively be used, which includes the various links for each
terminal end-point 20.
The network-resident service node 18 is operative to receive
incoming calls routed by the CCSE 16 and provides an appropriate
service to handle the incoming call. The service may be a
conventional voice mail service, a personal assistant service, call
forwarding service, or the like. The service node preferably
includes a multi-point controller 34 (MC) that supports multi-party
conferences (FIG. 2). The service node further includes service
logic 36, an external service access manager 38, a multi-thread
interface 40, and plural H.323 stacks 41. The primary communication
path between the CCSE and the service node is H.323 signaling
between the respective stacks. The CCSE and service node each
include multiple stacks, with one stack from each being paired to
accommodate a particular incoming call. Thus, multiple calls may be
handled at any time. The multi-thread interface connects the
multiple stacks with the service logic device, so that the service
logic device may simultaneously process multiple incoming calls.
Alternatively, the system 10 could use a multiple process device,
in which each incoming call is processed by one of the
processes.
The CCSE 16 and service node 18 are preferably interconnected by
means of a common object request broker architecture (CORBA) based
data access utility 42 including plural CORBA interfaces 43. As is
well known to those skilled in the art, CORBA is a communication
protocol that allows two or more different components to
communicate with each other. Thus, in the preferred embodiment the
CORBA-based data access utility serves as the distributed object
mechanism between the feature selector and service node to support
communication therebetween. Alternatively, other mechanisms may be
used, such as Distributed Component Object Model (D/COM),
Distributed Computing Environment (DCE), and Remote Procedure Call
(RPC).
It will be apparent to those skilled in the art that the service
logic 36 of the service node 18 will vary depending on the type of
service being offered. For example, in the case of a voice mail
service, the service logic includes code for playing a prerecorded
digital or analog message, preferably a message recorded by the
user of the terminal end-point being called. After the message,
service logic accepts input from the caller, and stores the message
for future playback when the user of the called terminal end-point
accesses the voice mail subsystem of the service node. In the case
of a personal assistant (or automated attendant), the service logic
provides the caller with plural options, such as call forwarding,
voice mail, and the like. Depending on the option selected, the
call is either routed to another terminal end-point, or the device
accepts input in the form of a voice message, all of which is well
known to those of ordinary skill in the art.
The terminal end-points 20 are H.323 defined entities and include
both input and output equipment for supporting video and audio.
Preferably, the terminals include graphical user interfaces (GUIs)
for presenting line appearances in various formats, as is described
in more detail below.
The special features of the network system 10 of the present
invention are implemented, in part, by software programs stored in
memory. The software programs are accessible by the components of
the system, the function of which is described in greater detail in
connection with FIGS. 5 and 6.
Referring now to FIGS. 1 and 6, one preferred method of the present
invention will be described. A call placed by a user on the PSTN 22
is transmitted to the gateway 12. Initially, the gateway performs
the necessary translation into the H.323 format. Next, the
translated signal is transmitted to the gatekeeper 14, which
receives the signal and performs the access control function in
order to authorize the call from the caller. Possible reasons for
rejection may include restricted access to or from particular
terminals or gateways, restricted access during certain time
periods, and the like.
Assuming that the caller is authorized, operation proceeds and the
gatekeeper 14 directs the gateway 12 to establish a signaling path
directly to the signal routing device, in this case the CCSE 16.
The CCSE receives the logical address for the call, such as a
specific E. 164 address, at step 44. The CCSE then accesses a
database and uses the logical address to determine the
corresponding terminal IP address. In a preferred embodiment, the
feature selector 24 then accesses the first association table 27 of
the call management database 26 at step 45. The feature selector
searches the first association table for the address line 29
corresponding to the called terminal end-point 20 to determine
whether a service node has been linked with that terminal end-point
for initial call presentation, at step 46. If no service node is
linked with the terminal end-point in the first association table,
then operation proceeds
to step 47, and the call is routed to the terminal end-point and
presented to the user. If, on the other hand, a service node is
linked with the terminal end-point in the first association table,
operation instead proceeds to step 48, and the call is routed to
the appropriate network-resident service node end-point which
handles the incoming call and provides one or more service options
to the caller, as described above. In that event, operation then
proceeds back to step 44, and the system 10 handles the next
incoming call.
If the call is routed to the terminal end point, operation flows to
step 49, and the CCSE 16 monitors whether the call is accepted by
the terminal end-point 20. For example, the CCSE may monitor
whether an alert or connect signal is received from the terminal
end-point within a predetermined period of time. If so, the call is
connected, operation flows back to step 44, and the system 10
handles the next incoming call. If the call is not accepted within
a predetermined period of time, for example ten seconds, operation
proceeds to step 50, and the feature selector 24 is operative to
access the second association table 28 of the call management
database 26 to determine the appropriate service node to handle the
call. Such determination is made by simply finding the address line
29 (FIG. 3) corresponding to the appropriate terminal end-point in
the second association table, and determining the corresponding
service node that is linked to that terminal end-point. Operation
then flows to step 51, and the incoming call is routed by the CCSE
to the appropriate service node. Operation then proceeds back to
step 44, and the system handles the next incoming call.
Referring now to FIG. 4, there is shown a second embodiment of the
network system 52 of the present invention. The network system
comprises a gateway 53, plural gatekeepers 54, 56, and 58, a CCSE
60, at least one terminal end-point 62, and plural network-resident
service nodes 64, 66, and 68. The gateway 53 is in communication
with a PSTN 70 for two-way communication therebetween, as described
above in connection with the first described embodiment.
Alternatively, instead of being in communication with the PSTN, the
gateway could be in communication with another PBN or with some
other SCN.
The first gatekeeper 54 is in communication with the gateway 53 to
receive, for example, the translated E.164 address from the
gateway. The first gatekeeper 54 is operative to multicast a
location request to plural gatekeepers (only the affirmatively
responding gatekeeper 56 is shown in FIG. 4) to locate the
gatekeeper that services a particular dialed number, as is
described in greater detail below.
The CCSE 60 is also connected to the gateway 53 for communication
therewith, as well as with the affirmatively responding gatekeeper
56. The CCSE serves as the signal routing agent for the call
signals, and communicates directly with the gateway. As with the
previous embodiment, a call routing gatekeeper can be used in the
place of the CCSE. The CCSE is also in communication with the
terminal end-point 62 ("T1"), and with the plural network-resident
service nodes 64, 66, and 68.
The second gatekeeper 56 is also in communication with T1, and with
a third gatekeeper 58. The third gatekeeper, in turn, is connected
with the various network-resident service nodes 64, 66, and 68.
Referring to FIG. 5, there is shown a timing diagram for the
signaling involved according to one embodiment of the present
invention. The signaling functions in one illustrative embodiment
use H.323/Q.931 protocol. Initially, an outgoing call placed from a
telephone device A in, for example, the PSTN is transmitted as a
Setup (1) signal through the PSTN switching network (SW), and to
the gateway 53 as a Setup (2) signal. The gateway then transmits an
admission request (ARQ) signal ARQ (3) that is received by the
first gatekeeper 54. The first gatekeeper is then operative to
multicast a location request (LRQ) signal LRQ (4) to locate the
gatekeeper that services the number dialed at the telephone device
A. The second gatekeeper 56, which services the number dialed, then
transmits a location confirmation (LCF) signal LCF (5) back to the
first gatekeeper 54, informing the first gatekeeper as to the
location of the corresponding terminal end-point. The first
gatekeeper then transmits an admission confirmation (ACF) signal
ACF (6) to the gateway 53 with the IP address of the corresponding
signal routing agent, in this case the CCSE 60, that services the
number dialed. The ACF (6) signal also serves to direct the gateway
to establish a direct signaling path to the CCSE.
The gateway 53 then transmits a Setup (7) signal to the CCSE 60,
corresponding to step 44 in FIG. 6. The CCSE responds with a Call
Proceeding (8) signal transmitted back to the gateway. The CCSE
then transmits an ARQ signal ARQ (9) to the second gatekeeper 56
requesting to communicate with the terminal end-point T1 or "Bip".
The second gatekeeper 56 then transmits an ACF signal ACF (10) back
to the CCSE authorizing the CCSE to communicate directly with the
end-point T1. A second ARQ (11) signal is transmitted by the CCSE
to the second gatekeeper, which responds with a second ACF (12)
signal. The first ARQ signal ARQ (9) is an admissions check for the
incoming call, and the second ARQ signal ARQ (11) is an attempt to
map an H.323 alias, determined from the information input by the
calling party, to an IP address in order to complete the call.
The CCSE then transmits a setup signal Setup (13) to T1, which in
one preferred embodiment appears in the form of a line appearance
at the graphical user interface ("GUr") of T1. T1 transmits a
CallProceeding (14) signal back to the CCSE to inform the CCSE that
the call is being placed. The terminal end-point T1 then transmits
an ARQ signal ARQ (15) to the second gatekeeper 56. The gatekeeper
responds with an ACF signal ACF (16), which includes the call
signaling channel transport address of the CCSE. The end-point T1
then transmits an alert signal Alert (17) directly to the CCSE
indicating that the call is proceeding and is being presented at
terminal end-point T1 . Respective alert signals Alert (18), Alert
(19), and Alert (20) are transmitted through the gateway 53 and
PSTN 70 to the caller's telephone device A.
The CCSE 60 is then programmed to wait for a predetermined period
of time for the terminal end-point T1 to accept the call,
corresponding to step 49 in FIG. 6. If, after the predetermined
amount of time has elapsed, the CCSE has not received a connect
signal from the terminal end-point, the feature selector 24 is
programmed to access the second association table 28 to determine
the corresponding service node linked to T1, corresponding to step
50 in FIG. 6. Assuming the service node comprises the voice mail
terminal VM.sub.1, the CCSE then transmits an appropriate ARQ
signal ARQ (21) to the second gatekeeper 56. The second gatekeeper
then transmits a LRQ signal LRQ (22), which is responded to by the
third gatekeeper 58 in the form of a LCF signal LCF (23), which
informs the second gatekeeper as to the location of the
corresponding service node. The second gatekeeper then transmits an
admission confirmation (ACF) signal ACF (24) to the CCSE 60 with
the IP address of the corresponding network-resident service node.
The ACF (24) signal also serves to direct the CCSE to establish a
direct signaling path to VM.sub.1. The CCSE then communicates
directly with VM.sub.1 in the form of a Setup (25) signal,
corresponding to step 51 in FIG. 6. VM.sub.1 responds with a
CallProceeding (26) signal back to the CCSE, and transmits an ARQ
(27) signal to the third gatekeeper 58. The third gatekeeper
transmits a corresponding ACF (28) signal to VM.sub.1, which
responds with an Alert (29) signal to the CCSE 60, followed by a
Connect (30) signal which is received by the CCSE. The CCSE then
transmits a Connect (31) signal to the gateway 53, which sends
Connect (32) signal to the PSTN switch SW, which in turn transmits
a Connect (33) signal to the caller's communication device, thereby
establishing a communication channel between the caller and
VM.sub.1.
In a preferred embodiment, before the ARQ (9) signal is transmitted
by the CCSE 60, the feature selector 24 accesses the first
association table 27 of the call management database 26 to
determine whether the terminal end-point T1 is linked with a
service node for initial call presentation. If so, the next signal
transmitted is the ARQ (21) signal to the second gatekeeper 56. If
not, the signaling proceeds as shown in FIG. 5 and as described
above.
The system 10 of the present invention in one illustrative
embodiment may be incorporated in a hierarchical communications
network, as is disclosed in co-pending U.S. Pat. application Ser.
No. 60/105,326 (Attorney Docket Number 98-808) of Gardell et al.
entitled "A HIGH SPEED COMMUNICATIONS SYSTEM OPERATING OVER A
COMPUTER NETWORK", and filed on Oct. 23, 1998 the disclosure of
which is incorporated herein by reference. Thus, the various
network-resident service capabilities disclosed herein may be
implemented in a nationwide or even worldwide hierarchical computer
network.
From the foregoing, it will be apparent that the network system 10
of the present invention modifies existing H.323-based
communications systems to provide a network presence in the event a
terminal end-point is unavailable, and provides various services at
the network level rather than at the client level.
While the invention has been particularly shown and described with
reference to preferred embodiments thereof, it will be understood
by those skilled in the art that various changes in form and
details may be made therein without departing from the spirit and
scope of the invention.
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