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Claims  |
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We claim:
1. A method of processing telephone calls comprising the steps of
monitoring signaling messages associated with telephone calls processed by
a switch, when said messages are received in a signal transfer point
connected to said switch,
when a signaling message is determined to be an Initial Address Message
(IAM), thereby indicating that it represents a new call arriving in said
switch for processing, sending a copy of said signaling message to a call
selection processor;
in said call selection processor, examining information contained in said
signaling message to determine if said new call is to receive special
treatment; and
when said new call is to receive special treatment, (a) transmitting a
message from said call selection processor to said switch, directing said
switch to await further instructions; (b) transmitting a query message
pertaining to said new call from said call selection processor to an
applications processor; (c) transmitting a response to said query
containing treatment instructions from said applications processor
directly to said switch; and (d) processing said new call in accordance
with said treatment instructions.
2. The method defined in claim 1 wherein when said new call is not to
receive special treatment, said method includes the step of transmitting a
message from said call selection processor to said switch, directing said
switch to proceed with call processing.
3. The method defined in claim 1 wherein said information examining step
includes examining information relating to the origin and/or destination
of said new call.
4. The method defined in claim 1 wherein said query message includes origin
and/or destination information contained in said IAM.
5. The method defined in claim 1 wherein said call selection processor is
further arranged to process each call by:
examining information contained in said signaling message relating to the
origin and/or destination of said new call to determine if said new call
is to be terminated; and
when said new call is to be terminated, routing a message from said call
selection processor to said switch directing said switch to terminate said
call.
6. A method of processing originating telephone calls in a
telecommunications network, said network including a switch for receiving
said originating telephone calls and processing said originating telephone
calls in accordance with call treatment instructions, said network
including a call selection processor connected to said switch for
processing signaling messages associated with said telephone calls, said
method comprising the steps of
monitoring signaling messages transmitted to said call selection processor
to identify particular ones of said signaling messages indicating said
originating telephone calls,
responsive to identification of said particular ones of said signaling
messages, querying a database using information relating to said
originating telephone calls, which information is contained in said
particular ones of said signaling messages, to determine if any of said
originating telephone calls require special treatment; and
for the ones of said originating telephone calls that require special
treatment, transmitting a message from said call selection processor to
said switch, directing said switch to await said call treatment
instructions for said ones of said originating telephone calls.
7. The method defined in claim 6 wherein said information relating to said
ones of said originating telephone calls includes calling and called party
information.
8. The method defined in claim 6 further including the steps of
transmitting a query message pertaining to said ones of said originating
telephone calls to an applications processor,
routing a response to said query, containing said call treatment
instructions for each of said ones of said originating telephone calls,
from said applications processor directly to said switch.
9. The method defined in claim 6 further including the step of processing
said ones of said originating telephone calls in accordance with said call
treatment instructions.
10. The method defined in claim 6 wherein, when other ones of said
originating telephone calls do not require special treatment, transmitting
a message to said switch, directing said switch to proceed with the
processing said other ones of said originating telephone calls using
default call treatment instructions.
11. A method of processing telephone calls in a telecommunications switch
arranged to receive and process calls in accordance with call treatment
instructions, said method comprising the steps of
upon receipt in said telecommunications switch of a call requiring
processing, initiating a timing process for said call,
when a signaling message pertaining to said call is subsequently received
in said telecommunications switch before termination of said timing
process, processing said call in .said telecommunications switch in
accordance with call treatment instructions contained in said signaling
message, and
when a signaling message pertaining to said call is not subsequently
received in said telecommunications switch before termination of said
timing process, transmitting a query from said telecommunications switch
to request said call treatment instructions.
12. A method of processing telephone calls to obtain call treatment
instructions for said telephone calls, said method comprising the steps of
receiving signaling messages associated with call originations;
responsive to receipt of said signaling messages, querying a database using
information relating to the calling and called parties involved in said
call originations to determine if particular ones of said call
originations require special treatment; and
when particular ones of said call originations require special treatment,
transmitting a message to a switch handling said particular ones of said
call originations, said message directing said switch to await said call
treatment instructions for said particular ones of said call originations.
13. A method of processing telephone calls to obtain call treatment
instructions for processing said telephone calls in a telecommunications
network switch, said method performed in a switch and in a call selection
processor and a signaling message processor each connected to said switch,
and said method comprising the steps of
responsive to receipt of said telephone calls in said switch, placing said
switch in a wait state to await said call treatment instructions;
responsive to receipt of signaling messages associated with call
originations received in said switch, sending a message from said
signaling message processor to said call selection processor that uses
information relating to the calling and called parties involved in said
telephone calls to determine if particular calls require special
treatment; and
when according to said call selection processor particular calls require
special treatment, causing said switch to continue to await said call
treatment instructions in response to a further signaling message directed
to said switch from said call selection processor.
14. The invention defined in claim 13 wherein said querying step further
includes determining the identity of a particular applications processor
to be used in processing said particular calls requiring special
treatment.
15. The method defined in claim 13 further including the steps of
transmitting a query message pertaining to said particular calls to an
applications processor.
16. The method defined in claim 15 wherein said query message includes
information relating to the calling and called parties involved in said
particular telephone calls.
17. The method defined in claim 13, wherein when said particular calls do
not require special treatment, said method further includes the step of
transmitting a message to said switch, directing said switch to proceed
with default call treatment instructions.
18. The method defined in claim 13, further including the steps of
storing a record in said database for each ANI, dialed number, and/or
credit card for which special treatment is desired, and
accessing said records during said querying step.
19. A method of processing telephone calls in a switch connected to an
associated signaling message processor, said method comprising the steps
of
monitoring signaling messages received in said signaling message processor,
each of said signaling messages being associated with a telephone call
received for processing in said switch,
copying by the signaling message processor a signaling message transmitted
to said signaling message processor if said signaling message is an
Initial Address Message (IAM), indicating that it represents a new call
arriving in said switch for routing and processing,
before processing of said new call in said switch, examining said
information in said copy of said signaling message to determine if said
new call requires special treatment; and
when said call requires special treatment, transmitting a message from said
signaling message processor to said switch, directing said switch to await
further instructions.
20. The method of claim 19 further including the step of transmitting a
message to said switch, directing said switch to proceed with call
processing when said new call does not require special treatment.
21. The method of claim 19 further including the steps of transmitting a
query message pertaining to said new call to an applications processor,
and
routing a response to said query containing processing instructions from
said applications processor directly to said switch.
22. The method of claim 19 wherein said information includes ANI
information contained in said signaling message relating to the called
party originating said new call.
23. The method of claim 19 wherein said information includes dialed number
information contained in said signaling message pertaining to the called
party to whom said new call is destined.
24. The method of claim 19 wherein said information includes both ANI
information contained in said signaling message relating to the calling
party originating said new call, and dialed number information contained
in said signaling message pertaining to the called party to whom said new
call is destined.
25. The method defined in claim 24 wherein said examining step includes
determining the address of a first applications processor based upon said
ANI information;
determining the address of a second applications processor based upon said
dialed number information; and
selecting the address of one said first and second applications processors
based upon predefined selection rules.
26. The method defined in claim 21 further including the step of processing
said call in said switch in accordance with said processing instructions
received from said applications processor.
27. Apparatus for processing telephone calls comprising
a switch arranged to receive a telephone call, a signaling message
processor connected to said switch and arranged to monitor signaling
messages associated with telephone calls processed by said switch,
a call selection processor connected to said signaling message processor,
means in said signaling message processor for sending a copy of any of said
signaling messages determined to be an Initial Address Message (IAM),
thereby indicating that it represents a new call arriving in said switch
for processing, to said call selection processor;
an applications processor connected to said call selection processor; and
means in said call selection processor for (a) examining information
contained in said signaling message to determine if said new call is to
receive special treatment and, when said new call is to receive special
treatment, for (b) transmitting a message to said switch, directing said
switch to await further instructions, and (c) transmitting a query message
pertaining to said new call to said applications processor.
28. The invention defined in claim 27 wherein said applications processor
includes means for transmitting a response to said query containing
treatment instructions directly to said switch.
29. The apparatus defined in claim 28 wherein when said new call is not to
receive special treatment, said applications processor is arranged to
transmit a message to said switch, directing said switch to proceed with
call processing.
30. The apparatus defined in claim 27 wherein said call selection processor
is arranged to examine information relating to the origin and/or
destination of said new call.
31. The apparatus defined in claim 27 wherein said query message includes
origin and/or destination information contained in said IAM.
32. A system of processing originating telephone calls in a
telecommunications network, said network including a switch for receiving
said originating telephone calls and processing said originating telephone
calls in accordance with call treatment instructions, said network
including a signaling message processor connected to said switch for
processing signaling messages associated with said telephone calls, said
system comprising
a database,
means in said signaling message processor for monitoring signaling messages
to identify particular ones of said signaling messages indicating said
originating telephone calls,
means in said signaling message processor responsive to identification of
said particular ones of said signaling messages, for sending to said
database messages that include information relating to said originating
telephone calls, which information is contained in said particular ones of
said signaling messages, to determine based on information in said
database, if any of said originating telephone calls require special
treatment; and
means for routing a message to said switch from said database, directing
said switch to await said call treatment instructions for ones of said
originating telephone calls that require special treatment.
33. The system defined in claim 32 wherein said information relating to
said ones of said originating telephone calls includes calling and called
party information.
34. The system defined in claim 32 further including
means for transmitting a query message pertaining to said ones of said
originating telephone calls to an applications processor, and
means for routing a response to said query message, containing said call
treatment instructions for each of said ones of said originating telephone
calls, from said applications processor directly to said switch.
35. The system defined in claim 32 further including means for processing
said ones of said originating telephone calls in accordance with said call
treatment instructions.
36. The system defined in claim 32 wherein, when other ones of said
originating telephone calls do not require special treatment, said
transmitting means is arranged to transmit a message to said switch,
directing said switch to proceed with the processing said other ones of
said originating telephone calls using default call treatment
instructions.
37. Apparatus for processing telephone calls in a telecommunications switch
arranged to receive and process calls in accordance with call treatment
instructions, comprising
means in said switch responsive to receipt of a call requiring processing,
for initiating a timing process for said call,
means in said switch for processing said call in accordance with call
treatment instructions contained in said signaling message when a
signaling message pertaining to said call is subsequently received before
termination of said timing process, and
means in said switch for transmitting a query to request said call
treatment instructions when a signaling message pertaining to said call is
not subsequently received before termination of said timing process.
38. Apparatus for processing telephone calls to obtain call treatment
instructions for said telephone calls, comprising
means for receiving signaling messages associated with call originations;
means responsive to receipt of said signaling messages, for querying a
database using information relating to the calling and called parties
involved in said call originations to determine when particular ones of
said call originations require special treatment; and
means for transmitting a message to a switch handling said telephone calls,
said message directing said switch to await said call treatment
instructions handling said telephone calls when particular ones of said
call originations require special treatment.
39. Apparatus for processing telephone calls to obtain call treatment
instructions for processing said telephone calls in a telecommunications
network, comprising
a switch in said network; a call selection processor and a signaling
message processor each connected to said switch;
means in said switch responsive to receipt of said telephone calls, for
placing said switch in a wait state to await said call treatment
instructions;
means in said signaling message processor responsive to receipt of
signaling messages associated with call originations received in said
switch, for sending from said signaling message processor to said call
selection processor a message that uses information relating to the
calling and called parties involved in said telephone calls to determine
if particular calls require special treatment; and
means in said call selection processor, for transmitting a further
signaling message to said switch, said further signaling message directing
said switch to await said call treatment instructions for particular calls
that require Special treatment.
40. The invention defined in claim 39 wherein said call selection processor
further includes means for determining the identity of a particular
applications processor connected to elements in said network used in
processing said particular calls requiring special treatment.
41. The invention defined in claim 39 further including
means for transmitting a query message pertaining to said particular calls
from said call selection processor to an applications processor connected
to elements in said network.
42. The invention defined in claim 41 wherein said query message includes
information relating to the calling and called parties involved in said
particular telephone calls.
43. The invention defined in claim 39, wherein when said particular calls
do not require special treatment, said transmitting means is arranged to
transmit a message from said call selection processor to said switch,
directing said switch to proceed with default call treatment instructions.
44. The invention defined in claim 39, further including
means for storing a record in said database for each ANI, dialed number,
and/or credit card for which special treatment is desired.
45. A system for processing telephone calls comprising
means for monitoring signaling messages received in a signaling message
processor, each of said signaling messages being associated with a
telephone call received for processing in a switch connected to said
signaling message processor,
means for copying a signaling message transmitted to said signaling message
processor if said signaling message is an Initial Address Message (IAM),
indicating that it represents a new call arriving in said switch for
routing and processing,
means for examining information in said copy of said signaling message
before processing of said new call in said switch, to determine if said
new call requires special treatment; and
means for transmitting a message to said switch, directing said switch to
await further instructions if said call requires special treatment.
46. The system of claim 45 wherein said transmitting means is arranged to
transmit a message to said switch, directing said switch to proceed with
call processing when said new call does not require special treatment.
47. The system of claim 45 further including means for transmitting a query
message pertaining to said new call to an applications processor, and
means for routing a response to said query containing processing
instructions from said applications processor directly to said switch.
48. The system of claim 45 wherein said information includes ANI
information contained in said signaling message relating to the called
party originating said new call.
49. The system of claim 45 wherein said information includes dialed number
information contained in said signaling message pertaining to the called
party to whom said new call is destined.
50. The system of claim 45 wherein said information includes both ANI
information contained in said signaling message relating to the calling
party originating said new call, and dialed number information contained
in said signaling message pertaining to the called party to whom said new
call is destined.
51. The system defined in claim 50 wherein said examining means includes:
means for determining (a) the address of a first applications processor
based upon said ANI information; and (b) the address of a second
applications processor based upon said dialed number information; and
means for selecting the address of one said first and second applications
processors based upon predefined selection rules.
52. The system defined in claim 47 further including means for processing
said call in said switch in accordance with said processing instructions
received from said applications processor. |
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Claims |
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Description |
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FIELD OF THE INVENTION
This invention relates generally to telecommumcations, and, in particular,
to a telecommunications architecture and system wherein all calls routed
to a switch are examined and processed in a manner that permits "selected"
calls to be differentiated from other calls, so as, for example, to allow
the selected calls to receive special treatment.
BACKGROUND OF THE INVENTION
Telecommunications service providers desire to arrange their network so
that the call processing logic applied to each call can be customized,
i.e., each call given individualized treatment. This is advantageous from
the customer (caller) point of view, since the customer will obtain better
service. It is also advantageous from the network provider point of view,
since it enables segment specific strategies, i.e., allows marketing
tailored to individual customer groups.
Today's interexchange networks are not arranged to routinely determine
customer identification and provide customized treatment at the time of
call origination. Rather, existing networks have been optimized for
"simple" calls, and such networks handle calls requiring special treatment
on an "exception" basis. In present arrangements, the customer is not
identified directly, at the beginning of the call processing process, so
that customer-specific features are applied to a particular call only
after a great deal of processing. The difficulty is illustrated by one
example involving call processing instructions: currently, service type is
first identified using a table that associates trunk group type with
service type. Automatic number identification (ANI) information may be
collected from the caller and sent to an ANI vs customer table, to further
identify the customer. Next, the ANI and customer identification are sent
to a customer vs allowed feature table, to obtain a list of authorized
features. Finally, processed data obtained as a result of the foregoing
table look-up is sent back to the switch that is processing the call to
execute whatever call processing is appropriate. Other aspects of call
treatment, such as access and egress determination and recording/billing
arrangements, can be equally complex.
The problem with this approach is that the various tables just described
are distributed rather than centralized. These tables have to be
provisioned, i.e., stored, when a customer first obtains a service or
feature, and coordinated among themselves when a customer makes a change.
This is costly, complicated, time consuming and error prone. Also, there
is no central record of "who has what"; this complicates customer inquiry
response and maintenance of the network elements.
SUMMARY OF THE INVENTION
The present invention provides real time call control within a
telecommunications network, using a call selection processor separate from
the switches carrying the call, which responds to incoming calls and uses
information carried in the associated signaling messages to determine what
application processor, if any, should be involved on the call. One
embodiment of the present invention includes a call selection processor
called a signaling director", or "SD" for short, for recognizing certain
signaling messages, typically SS7 initial address messages (IAM's), as the
messages flow through the signaling network. Alternatively, particular
signaling messages may be recognized in a signaling message processing
element within the signaling network, such as the signal transfer point
(STP) associated with the switch that receives the telephone calls, and a
copy of those particular messages forwarded to the SD.
The SD examines information in the particular messages, generally
information relating to the originating user and destination of each call,
and then transmits an "action message" to the switch to direct the switch
as to "what to do next". For selected calls, for example, calls that
require special treatment, the SD transmits an action message to the
switch, directing the switch to await further instructions. The SD then
transmits a query message pertaining to the selected call to an
appropriate applications processor, also determined based upon information
about the calling and called parties gleaned from the IAM. After the query
is processed in the applications processor, a response is returned
directly to the switch, containing the required call treatment
instructions. Those calls that are not "selected" calls are identified in
the SD, and a "proceed" action message is sent to the switch, directing
that the calls be conventionally treated.
In accordance with an aspect of the invention, the switch is arranged to
wait after receiving the initial incoming call message (i.e., the IAM) and
then begin a timing process in response to receipt of this call, so that
if an action message for that call does not arrive within a predetermined
time period, a query can be launched to obtain such action message.
Likewise, if an action message that requests the switch to await call
treatment instructions for a "selected" call is received, the switch can
begin a second timing process, so that, if those instructions do not
arrive within a predetermined time, a query can be launched to obtain such
instructions.
If a call is received in a switch via a direct connection such that
signaling information is provided by multi-frequency tones, ISDN signaling
or other means rather than via an SS7 signaling message, then the present
invention may process such calls by launching a query from the switch to
the SD.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully appreciated by consideration of
the following detailed description, which should be read in light of the
accompanying drawing in which:
FIG. 1 is a block diagram of the telecommunications network architecture of
the present invention, illustrating an implementation within an
interexchange carder network;
FIG. 2 is a diagram illustrating the signaling messages received and/or
generated by certain of the network elements of FIG. 1;
FIGS. 3 and 4 illustrate the processes performed in switch 130 of FIG. 1,
relating to signaling messages;
FIG. 5 illustrates the relationship between FIGS. 3 and 4;
FIG. 6 illustrates the processes performed in SD 150 of FIG. 1;
FIG. 7 is a block diagram of a typical Signal Director (SD) in accordance
with the present invention; and
FIG. 8 illustrates the connection arrangement among a series of SD's,
applications processors, telecommunications switches, and signaling
message processors.
DETAILED DESCRIPTION
Referring first to FIG. 1, there is shown a block diagram of the
telecommunications network architecture of the present invention,
illustrating the relationship between the major components when the
invention is used in the context of an interexchange carder
telecommunications network, such as the network of AT&T. (Note here that
the invention could also be implemented in the context of a local
(intraexchange) telephone network, for example, in a terminating switch
within a local exchange carder (LEC) network; this type of arrangement is
discussed in more detail below. When a telephone call is originated from a
point of origin, such as telephone 101, the call is received in a switch
111 of a first local exchange carrier (LEC) network 110 which serves the
subscriber for that telephone. If the call is an interexchange call
destined for a destination, such as telephone 102, served by a different
LEC network 120, the call is connected to the appropriate gateway switch
(switch 130 in FIG. 1 ) in the interexchange network. The interexchange
network routes the call via a transport network shown generally as 135 to
the appropriate interexchange terminating switch, switch 132 in FIG. 1,
which thereafter connects the call to switch 121 in LEC network 120, that
serves telephone 102. Of course, many other subscribers, not shown, are
served by each LEC, many LEC's are served by the interexchange network,
and the interexchange network includes many other switches. Our invention
is also applicable to calls received in the interexchange network via an
alternate access vendor instead of a LEC.
Signaling messages which control the process of setting up the call path
through switches 111 and 121 in networks 110 and 120 and switches 130, 132
in the interexchange network may follow the well known Signaling System 7
(SS7) protocol defined by Study Group XI-Specification of Signaling System
No. 7, International Telegraph and Telephone Consultative Committee
(CCITT) Blue Book, Vol. 6 of Facile VI.9, Geneva, Switzerland, 1989. The
signaling messages are originated and processed in a series of signaling
message processors, typically signal transfer points (STP's), including
STP 112 associated with originating switch 111, STP 122 associated with
switch 121, and STP's 141 and 142, associated with the switches 130 and
132, respectively, and are transported between STP's using a signaling
network shown generally as 140. Normally, STP's are provisioned in pairs,
for reliability purposes; the "inate" to each STP in FIG. 1 is not shown.
This is described in more detail below, in conjunction with FIG. 8.
Signaling messages, signaling protocols, the conventional signaling
network architecture, and the internal arrangement of STP's are all well
known to persons skilled in telecommunications architecture development,
and are described, for example, in an article by Modarressi and Skoog
entitled "Signaling System No. 7: A Tutorial", IEEE Communications
Magazine, July 1990, page 19 et seq. Note here that signaling messaging
processors, as contemplated by the present invention, can include not only
conventional STP's, but also the network endpoint signaling transfer point
(NESTP) arrangement described in patent application Ser. No. 07/958845
filed Oct. 9, 1992, entitled "Telecommunications System SS7 Signaling
Interface with Loose Coupling to its Host filed by Blatchford et al. and
assigned to the same assignee as the present application.
In accordance with the present invention, a call selection processor called
a signal director (SD) is a network element having the properties of a
"full signaling end point" that is arranged to receive information
relating to calls connected to any of the switches served by the SD, when
those calls are call originations. In FIG. 1, SD 150 is shown as connected
to STP 141, so that it can receive a copy of each initial address message
(IAM) associated with origination of calls extended from switch 111 to
switch 130. Likewise, a second SD 151 is shown connected to STP 142, so
that it receives a copy of certain signaling messages (IAM's) relating to
origination of calls extended from switch 132 to switch 122. If a
signaling message indicates that it represents a message other than an
IAM, such as a message relating to on-going calls or calls that are being
torn down, copies are not provided to the SD. Note that other alternatives
exist for sending call set up messages (IAM's) to the SD. In particular,
the SD could monitor all the signaling links directly and itself extract
and process those particular messages relating to calls arriving in a
switch. Alternatively, the STP could send copies of all messages to the
SD, and the SD could likewise extract some of the messages.
When SD 150 receives a signaling message containing information relating to
a call origination, such as a copy of an IAM, it examines information in
that signaling message relating, in general, to the calling and called
parties, such as the dialed number and/or the ANI information for the
call, to determine if the call requires special treatment. This
examination is accomplished through a query to a database in or associated
with the SD, using the dialed number, ANI, or other information in the
signaling message as a query key. If the call does require special
treatment, a message is transmitted from the SD to an appropriate
applications processor (AP), such as applications processor 160 in FIG. 1.
The last mentioned message is a query also containing information relating
to the call, typically including the dialed number and ANI. This message
is transmitted from SD 150 to STP 141 and then directly (or through other
STP's in signaling network 140) to applications processor 160. Note here
that the calling party information can include, in addition to or in lieu
of ANI information, information derived from the caller's credit card or
telephone calling card, or other information, and the called party
information can include, in addition to or in lieu of dialed number
information, information which is translated or derived from the dialed
number.
Applications processor 160 may be configured much like a network control
point (NCP) currently available from AT&T, and is essentially a database
arranged to receive queries, look up stored information in accordance with
retrieval keys contained in the queries, process that information in order
to implement call processing, billing, recording or other functions, and
return messages containing instructions for call processing or other
switch actions. In accordance with the present invention, the call
treatment messages are returned "directly" to the switch processing the
call, in this case switch 130, meaning that the instructions are not
returned to the SD that queried the application processor. Rather, the
call treatment instructions proceed through STP 141 (and possibly through
other STP's in signaling network 140) to switch 130.
Switch 130, as shown in FIG. 1, includes the conventional functional
components typically found in a switch such as the 4ESS.TM. program
controlled switch available from AT&T. These components are a signaling
interface 131 for receiving signaling messages routed to the switch from
the signaling network, including messages from STP 112, SD 150 and
applications processor 160, and a CPU 136 for processing calls in
accordance with call treatment instructions contained in such messages and
with stored instructions that control other switch functions. A database
134 may include other program instructions and/or data used in processing
calls. The switch fabric 133, through which calls are actually routed, is
connected to other elements in the IXC network, including elements in the
transport network 135 as well as switch 111 in LEC network 110.
Connections within switch fabric 133 are made under the control of
instructions received from CPU 136.
In accordance with the present invention, the programs that control the
operation of switch 130 are different from those available today. As
described in more detail below, switch 130 is arranged to begin certain
timing and counting processes in response to receipt of a call
origination, to await call treatment instructions for selected calls if
instructed by SD 150 to do so, and to process calls in accordance with
call treatment instructions received from applications processor 160 if
those instructions are received within a predetermined time period, and
otherwise to process the calls in accordance with default instructions.
FIG. 2 illustrates graphically the sequence in which certain signaling
messages are received and/or generated by certain of the network elements
of FIG. 1 during call set up. The elements in FIG. 2 retain the same
reference designations as used in FIG. 1. The signaling messages are
numbered 1 to 5, indicating the sequence in which the messages are
generated. The first message, message 1, represents an IAM transmitted by
STP 141 to switch 130, as a result of a call being originated and applied
to switch 130. This IAM, which actually originates in switch 111 within
LEC network 110, is routed via STP 112 and STP 141 to switch 130, and
typically includes information pertaining to the dialed number, as well as
ANI information pertaining to the originating telephone. However, in some
situations, the IAM may include other information, such as a call type
indicator and/or calling card number.
In accordance with the present invention, when message 1 is recognized by
STP 141 as an IAM, a copy of the message is made, packaged in a Signaling
Connection Control Part (SCCP) envelope and transmitted to SD 150 as
message 2 using SS7 message transfer part (MTP) routing. In accordance
with the invention, when SD 150 receives message 2, it queries its own
database to determine if special treatment will be provided for the call,
based upon the information provided in the IAM, typically dialed number
and ANI. The SD generates message 3, called an action message (AM), and
sends the AM through STP 141 to CPU 136 in switch 130 via signaling
interface 131, directing that switch (a) proceed with processing, in the
case of a call that is not a "selected" call, for example, a call that
does not require special treatment, (b) wait for further instructions, in
the case of a selected call, for example, a call that does require special
treatment, or (c) deny or "kill" the call, in the case of certain other
calls which which originate from certain telephones, are destined for
certain telephones, or otherwise have characteristics recognized as
indicating that such calls should be blocked or terminated. Note that in
most applications, the action message described above will be formatted as
a TCAP message, in accordance with CCITT recommendations Q.771 through
Q.775, and routed via SS7 SCCP and MTP routing, in accordance with Q.711
through Q.714 and Q.701 through Q.704.
In the case of selected calls, e.g., calls requiring special treatment, SD
150 then generates a query message 4, requesting routing and processing
information for the call, and routes the query to an appropriate
applications processor, in this example, applications processor 160 shown
in FIGS. 1 and 2. Routing of query message 4 (which also may be a TCAP
message routed using SS7 SSCP routing) is via STP 141 and possibly other
STP's in signaling network 140. Generally speaking, the query includes
information obtained from the IAM, such as dialed number and ANI. In
response to the query message 4, applications processor is arranged to
generate call treatment instructions contained in a signaling message 5,
and transmit that message directly to switch 130, advising the switch how
to proceed. As stated above, the path for message 5 is from applications
processor 160 through STP 141 and possibly other STP's in signaling
network 140, without passing through SD 150. The call treatment
instructions can include call processing instructions, access and egress
instructions, recording and billing instructions, and so on. These
instructions can, among other things, be used in switch 130 to enable
certain features to be applied to the call, such as subaccount billing,
abbreviated dialing, call forwarding, sequence calling, etc.
The messages described above can be more fully appreciated by considering
FIGS. 3 and 4, which illustrate the processes performed in switch 130, and
FIG. 6, which illustrates the processes performed in SD 150.
The process performed in switch 130, illustrated in FIGS. 3 and 4, is
initiated when an IAM is received in step 301. This causes initialization
of an "SD count" in step 303 (for purposes described below) and initiation
of an SD timer in step 305, which allows the switch to query the SD if the
SD does not provide an action message within a predetermined time. In
particular, a determination is made in step 307 as to whether the SD timer
has timed out. If so, a determination is made in step 313 as to whether or
not the SD count has been exceeded, this being done to assure that an
excessive number of queries are not launched. If the result in step 313 is
negative, i.e., if the SD count threshold is not exceeded, a query is
launched from the switch to the SD in step 315, and the SD count is
incremented in step 317. The process then continues with step 305. On the
other hand, if the result in step 313 is positive, indicating the the
number of queries launched exceeded the SD count threshold, the switch is
arranged to proceed without the AM, in step 319. This means that the
switch will process the call conventionally.
Note here that the timing and querying processes performed in the switch
are considerably different from current processing. Conventionally, a
switch may receive a signaling message and, in response to the message,
generate a query. To protect against the possibility that a response to
the query will be delayed or never received, the switch conventionally
begins a timing process when the query is launched, so that another query
or default processing can occur if the timer "times out". By way of
contrast, in accordance with the present invention, the switch begins
timing in step 305 in response to receipt of a signaling message. This is
because the switch will receive instructions in an action message from the
SD (proceed, wait or deny) without the need to launch any query.
Until the SD timeout period occurs, switch 130 monitors for an action
message in step 309; this can be a "proceed instruction", which causes the
switch to proceed with call processing in step 319, a "deny instruction",
which causes the switch to provide "final handling" in step 311, or a
"wait instruction", which places the switch in a wait state until a
message containing call treatment instructions is received from
applications processor 160.
If the action message received by the switch in step 309 is a wait message,
the process continues with steps 321 and 323, in which an "AP count" is
initialized (for purposes described below) and an AP timer is started,
respectively. This timer allows the switch to query the applications
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