WO2012125046A1

WO2012125046A1 - Method and system for processing telephony calls

Info

Publication number: WO2012125046A1
Application number: PCT/NZ2012/000036
Authority: WO
Inventors: Bruce Brown
Original assignee: Bruce Brown
Priority date: 2011-03-11
Filing date: 2012-03-12
Publication date: 2012-09-20
Also published as: NZ591694A

Abstract

A communications system having a transit switch for forwarding telephony calls. The transit switch has detector that detects whether a forwarding call is being diverted or is about to be diverted. The transit switch also includes a releasing function to release the call in response to the detector detecting that the forwarded call is being diverted or is about to be diverted. The communications system disconnects the call before the diverted call is completed so that no call charge is made to the caller. The communications system further includes an originating exchange, transit exchange and destination exchange whereby the originating exchange is able to forward calls to the transit exchange which includes the transit switch, and the transit exchange is able to forward the calls to a destination exchange.

Description

METHOD AND SYSTEM FOR PROCESSING TELEPHONY CALLS

Field of the Invention

This invention relates to telephony and telephony networks in particular to methods and systems for disconnecting a call before the diverted call is completed.

Background of the Invention

Telephony calls are frequently diverted to voicemail services. This often occurs with calls to cellular telephones that are switched "off or are in use.

Call diversion, particularly diversion to a voicemail service, can be a problem for callers in that diversion occurs automatically. Once connection to the voicemail service occurs, a call is made and the caller will usually have to pay for the call even though the caller may not wish to leave a message, and may not even leave a message.

Since the introduction of answering machines and since the emergence of firstly, telephone land line and then secondly, cellular telephone exchange based auto answer voicemail systems, telephone calls have been automatically terminated if the called party's telephone is either switched off, out of cellular range, busy with no call waiting or diverting on no reply.

This "Advancement." of telephone technology means generally that call charging begins automatically or almost automatically upon termination for all calls terminated in any of the above described scenarios. As a result of the automatic termination of telephone calls in the scenarios described above the calling party has no choice as to whether or not they would like to disconnect if the called party is unavailable and thus avoid being automatically charged for the call, or stay connected and leave a voicemail message and incur the call charge (Usually charged for the first full minute even if the voicemail message is less than a minute long). The global population of telephony subscribers has for decades accepted this mode of charging and paid their monthly telephone bills. Those telephone bills contain between 10 and 40 percent of call charges for automatically terminated phone calls that would not have been terminated and thus charged if the calling party had an option to disconnect before call termination and charging began automatically.

Object of the Invention

It is an object of the invention to provide a system or method for disconnecting a call before the diverted call is completed that goes at least some way toward overcoming disadvantages of existing systems, or which at least provides a useful alternative. Summary of the Invention

Accordingly in one aspect the invention broadly provides a method of processing a telephony call, the method including the steps of detecting when a call is being diverted, or is about to be diverted, and disconnecting the call before the diverted call is completed.

Preferably the step of disconnecting the call before the diverted call is completed results in no call charge being made to the caller.

Preferably the method includes the step of forwarding the call from an originating exchange to a transit exchange, and from the transit exchange to a destination exchange.

Preferably the step of detecting when the call is being diverted or is about to be diverted includes the step of receiving a signalling message at the transit exchange from the destination exchange.

Preferably the step of disconnecting the call includes the step of sending a message from the transit exchange to the originating exchange.

Preferably the method also includes the step of sending a message to the destination telephone or communication device to which the call was directed after the call has been disconnected following diversion being detected.

Preferably the message may include an SMS message.

Preferably the message includes information regarding the caller's telephone number or the caller's identity.

In a further aspect the invention broadly provides a method of processing a telephony call, the method including the steps of sending an Initial Address Message to a transit switch, forwarding the Initial Address Message from the transit switch to its intended destination, detecting at the transit switch when a Call Progress Message indicative of call diversion is received, and sending a Release message from the transit switch to prevent the call being made to the diverted destination.

In a further aspect the invention broadly provides a method of preventing a telephony call from being diverted to a voicemail service, the method including the steps of directing the call to a transit switch, forwarding the call from the transit switch to its intended destination, detecting at the transit switch whether the call is being diverted or is about to be diverted, and releasing the call to prevent the call being made to the diverted destination.

In a further aspect the invention broadly provides a communications system including a transit switch for forwarding telephony calls, the switch including detection means to detect whether a forwarding call is being diverted or is about to be diverted, and release means to release the call in response to the detection means detecting that the forwarded call is being diverted or is about to be diverted.

Preferably the system disconnects the call before the diverted call is completed so that no call charge is made to the caller.

Preferably the system includes an originating exchange which forwards calls to a transit exchange, and the transit exchange forwards the calls to a destination exchange.

Preferably the transit exchange may receive a signalling message from the destination exchange to detect when the call is being diverted or is about to be diverted.

Preferably transit exchange may send a message to the originating exchange to disconnect the call.

Preferably the system includes messaging means to send a message to the destination telephone or communication device to which the call was directed after being disconnected following diversion being detected.

Preferably the message may include an SMS message.

The invention also broadly consists in any new feature or combination of features disclosed herein. Any other aspects herein described Brief Description

The invention will now be described, by way of example only, by reference to the accompanying drawings: Figure 1A is a diagrammatic overview of a communication system architecture illustrating a telephony call between a PSTN telephone and a cellular telephone in accordance with a first preferred embodiment of the invention.

Figure IB is a diagrammatic overview of a communication system architecture illustrating a telephony call between two cellular telephones in accordance with a second preferred embodiment of the invention.

Figure 1C is a diagrammatic overview of a communication system architecture illustrating a telephony call between two PSTN telephones in accordance with a third preferred embodiment of the invention.

Figure 2A is a diagram showing a messaging call flow that may occur in relation to the architectures shown in the preceding figures.

Figure 2B is a diagram showing another messaging call flow that may occur in relation to the architectures shown in figures 1A to 1C.

Figure 3 is a diagram showing another messaging call flow that may occur in relation to the architectures shown in figures 1A to 1C.

Figure 4 is a diagram showing another messaging call flow that may occur in relation to the architectures shown in figures 1A to 1C.

Figure 5 is a diagram showing another messaging call flow that may occur in relation to the architectures shown in figures 1A to 1C.

Figure 6 is a flowchart in relation to the architectures shown in figures 1 A to 1C.

Figure 7 is a flow diagram showing the flow path for the TIO (terminating originating switch) in accordance to an embodiment of the invention.

Figure 8 is a flow diagram showing the flow path for the T2D (terminating destination switch) in accordance to an embodiment of the invention. Figure 9 is a flow diagram showing the user call flow of the invention in accordance to an embodiment of the invention.

Description of Invention

The invention provides a system and method for controlling the progress of a telephony call. The method and system allow telephony calls that are intended for a voicemail service, or a similar method of call completion, to be controlled so as to prevent a caller being charged for an undesired voicemail message.

The purpose of this invention is to offer telephone user a service that provides an option of hanging up or disconnecting their phone call before it diverts to voicemail and call charging commences.

If the telephone user does not wish to leave a voicemail message for the called party and incur call charges then the telephone user can (depending on the particular Telco configuration) either push 1 (or another Telco assigned number) or simply hang up within a certain time period to avoid incurring a call charge. Simply put the great advantage the invention offers those telephone users is the option for them to hang up or disconnect their call before call charging begins if they do not wish to leave a voicemail message for the called party.

On average the monthly telephone bill includes in it's call charges 10% to 40% of calls that are undesirably automatically terminated telephone calls. Thus the invention can significantly reduce a telephone users monthly Telco bill.

The invention has preferably two versions, the TIO (terminating originating switch) and the T2D (.terminating destination switch) Both the TIO and the T2D versions are preferably built using the IBM System x 3250M3 server platform. Linux is the operating system used. The telephony software is Asterisk - software version 10.2.0-rc2 and is used to drive the Digium TE121 telephony hardware. Asterisk is an open source framework for building communications applications.

Asterisk turns an ordinary computer into a communications server. Asterisk powers IP PBX systems, VoIP gateways, conference servers and more. It is used by small businesses, large businesses, call centres, carriers and governments worldwide.

The TIO version works in conjunction with the originating Central Office Switch (C.O.S.) or telephone exchange. It processes outbound calls and calls to other customers on the Telco's own network made by those customers that have activated the call terminating service the invention offers. The T2D version works in conjunction with the destination or terminating Central Office Switch (C.O.S.) and voicemail system. It processes inbound calls as grouped and directed by the Telco - i.e. Inbound, International, National, Local, Cellular etc.

Depending on the particular Telco's market strategy or the statutory requirements in different markets and locations, the local Telco may offer its customers either the outbound service based on the TIO version, the inbound service based on the T2D version or both.

Preferred embodiments of the invention will now be described in relation to the drawings.

Referring to figure 1A, a public switched telephone network (PSTN) telephone referenced 1 is shown connected to a PSTN network 2 which is in turn connected to a transit switch 3. As can be seen from figure 1 A, the PSTN 2 also provides a connection between the transit switch 3 and a further network switch such as a cellular communication network exchange 4 which allows a mobile communication device such as a cellular telephone 5 to be connected to the PSTN network. Therefore a telephone call made from a user of the PSTN phone 1 to the cellular telephone 5 will be made through the PSTN network to the transit switch 3, then back through the PSTN network 2 to the cellular exchange 4 and from there to the cellular telephone 5.

Referring to figure IB, architecture is shown for communication between two cellular telephone devices 5 and 6. In this instance, if the user of cellular telephone 5 wishes to make a call to cellular telephone 6, the call is directed by the cellular exchange 4 through the PSTN network 2 to the transit switch 3, and then back through the PSTN network 2, through the cellular network exchange 4 and onto the cellular telephone 6.

In figure 1C, an architecture that enables a call to make between PSTN telephone 1 and PSTN telephone 10 shows the call flow from one of the PSTN phones to the PSTN network 2 and onto the transit switch 3. From the transit switch 3 the call is directed back through the PSTN network 2 and onto the destination PSTN telephone.

Typically a user dialling from the PSTN network 2 will utilise the incumbent telco's Non Code Access and simply dial the number they desire to reach as per normal. Alternatively, the user may dial an access code (commonly known as Coded Access) along with the number they wish to call. For example, if non-code access is used, then the user will simply dial the required number, such as 09 915-1234. If Coded Access is used, then a prefix code is dialled, so the number may become 0523 915-1234, for example. The call is delivered to the transit switch 3 by the upstream carrier that provides access to the PSTN 2. The transit switch 3 then makes a normal outbound call to the number requested by the user. If the call is diverted to voicemail, then the transit switch 3 releases a call before it is answered by the voicemail system.

If the call is being made from a cellular phone, such as cellular telephone 5, then the general methodology may be the same as described above. Alternatively, the cellular telephone user may dial a predefined number. This will connected in the call to an exchange (not shown, but which may include transit switch 3) which will prompt the user to enter the intended destination telephone number. This allows a system to control the call. The system can then direct the call to the transit switch 3, which then directs the call on to the destination number.

Call flow will be discussed below in more detail using Common Channel Signalling System number seven (SS7) as an example. Those skilled in the art to which the invention relates will appreciate that ISDN protocol may also be used. It will also be apparent to those skilled in the art that use of the system in the ISDN protocol has the same basic structure as SS7 and employs the same method of initiating and releasing calls.

Referring to figures 1A and 2A, when the user of the PSTN telephone 1 makes a call intended for cellular telephone 5, the relevant exchange in the PSTN (not shown in figure 1 A, but labelled 2A in figure 2A) sends 20 an initial address message (IAM) to the transit switch 3. Switch 3 then takes control of the call and forwards 20 the IAM to the exchange 4. If the exchange 4 locates the cellular telephone and responds 21 with an Address Complete Message (ACM), meaning that the call to the cellular telephone is being completed, then the cellular telephone is polled and rings, and switch 3 passes 21 the ACM back to the originating exchange. 2 A However, if the cellular telephone is not answered and the exchange 4 has been instructed to divert the call when the telephone is not answered within a certain time period (commonly called "Call Divert No

Answer"), then the exchange 4 will send 22 a Call Progress Message (CPM) to switch 3. This message is representative of the call being diverted by exchange 4. The switch 3 then has a short period of time in which to act on this message before the exchange 4 diverts or completes diversion of the call. The switch 3 passes 23 a Release instruction (REL) back to the originating exchange 2A. The REL prevents the call from being completed. Accordingly, the call that would have been diverted, for example to a voicemail service, is terminated before it is connected, so the caller does not incur any call cost. Likewise, referring to figures IB and 2 A, the same basic call flow occurs, only the originating and destination exchanges 2A and 4 are both the cellular exchange 4.

In figures 1C and 2A, the same basic call flow process also occurs, only the originating and destination exchanges (or possibly just a single exchange) are provided within the PSTN network, so they are not shown separately in figure 1C (but are referred to as Exchange 2 A and Exchange 4 in figure 2A).

Referring to figure 2B, the second call flow shown in this figure is one where the target exchange 4 is instructed to divert calls to the destination telephone number immediately. This commonly called "Call Divert All". In this situation, the IAM is passed 20 by the transit switch 3 from the originating exchange 2 A onto the destination exchange 4. Since the call is to be diverted immediately, the exchange provides 22 a CPM message indicating imminent diversion to the transit switch 3. Therefore, the transit switch 3 immediately passes 23 an REL message to the originating exchange. This results in the call being terminated before any diversion occurs. This call flow is also applicable to the architectures of figures IB and 1C, as described above.

Furthermore, although not shown in the drawings, the transit switch 3 may be programmed to provide a message over the PSTN network 2 to a selected exchange such as a PABX whenever a call is released in response to a CPM message indicating diversion. The message may include information on the caller's telephone number, the destination telephone number, and possibly further information such as the date and time in which the caller made the call. In this way, if the destination telephone is a cellular telephone capable of receiving SMS (Short Message Service) or similar messages (such as MMS or messages that include picture elements or symbols), then the information received may be used by the system to forward an SMS message to the destination telephone. The SMS message may inform the user of the cellular telephone that someone tried to call them at a certain time of day, and that the caller can be contacted at the caller's telephone number. The advantage with sending an SMS message is it is likely to be less costly and using the voicemail service to which the original call would have been diverted.

Voicemail avoidance

Concept for call termination based on remote end diversion to voicemail

This pertains to the action to be taken by the Originating Exchange if a telephony voice call is diverted to voicemail. If a call is diverted to voicemail the call will be terminated by the Originating Exchange before the voicemail answers. Method will use the standard interconnection protocols ITU - SS7 and RFC3261 SIP.

Assumptions

• reader has basic knowledge of Telephone Network interconnection using ITU - T No. 7 Signalling

• reader has basic knowledge of VoIP protocol SIP RFC3261

• In Figures 3 to 5 the symbol ^-—-^ indicates action is taken by Originating Exchange.

Basic SS7 concept - terminate when diverting directly to voicemail, no ringing is heard by calling party (Figure 3)

Based on Telephone Network Interconnections using ITU - T No.7 Signalling PART C

ISUP Recommendation Q.763 and Q.764. The following steps are undertaken when the call is terminated when diverting directly to voicemail, no ringing is heard by calling party

• Initial Address Message (IAM) is sent 303 from Originating Exchange 301 to Terminating Exchange 302.

• Terminating Exchange 302 responds 304 with Address Complete Message (ACM).

• ACM contains Called Party status indication of "No Indication". No ringing is heard by the calling party.

• Terminating Exchange 302 sends 305 Call Progress Message (CPM) to Originating

Exchange 301 with Event Information set to Call Forward.

• Upon receipt of CPM the Originating Exchange 301 sends 307 a Release (REL) before voicemail answers.

• Terminating Exchange 302 acknowledges the release by sending a RLC (release complete).

• Call is terminated by both parties

Basic SS7 concept - terminate when diverting on No Answer to voicemail ringing is heard by calling party (Figure 3^")

ISUP Recommendation Q.763 and Q.764. The following steps are undertaken when the call is terminated when diverting on No Answer to voicemail, ringing is heard by calling party. • Initial Address Message (IAM) is sent 303 from Originating Exchange 301 to Terminating Exchange 302.

• Terminating Exchange 302 responds 304 with Address Complete Message (ACM)

• ACM contains Called Party status indication of "subscriber free". Ringing is heard by the calling party

Exchange 301 with Event Information set to Call Forward.

• Call is terminated by both parties

Basic SIP concept - terminate when diverting directly to voicemail, no ringing is heard by calling party (Figure 4)

Based on RFC3261 SB?: Session Initiation Protocol. The following steps are undertaken when the call is terminated when diverting directly to voicemail, no ringing is heard by calling party.

• SIP INVITE is sent from Originating Exchange 301 to Terminating Exchange 302.

• Terminating Exchange 302 responds 401 with 181 Call is Being Forwarded.

• No ringing is heard by the calling party.

• Upon receipt of 181 the Originating Exchange 301 sends 402 a CANCEL to the

Terminating Exchange 302.

• Terminating Exchange 302 acknowledges the CANCEL by sending 403 a OK to the

Originating Exchange 301.

• Call is terminated by both parties

Basic SD? concept - terminate when diverting on No Answer to voicemail. ringing is heard by calling party (Figure 5)

Based on RFC3261 SIP: Session Initiation Protocol. The following steps are undertaken when the call is terminated when diverting on No Answer to voicemail, ringing is heard by calling party.

• Terminating Exchange 302 responds 501 with 180 Ringing.

• Ringing is heard by the calling party.

• After approximately 20 seconds Terminating Exchange 302 responds 401 with 181 Call is Being Forwarded. • Upon receipt of 181 the Originating Exchange 301 sends 402 a CANCEL to the

Terminating Exchange 302.

• Terminating Exchange 302 acknowledges the CANCEL by sending 403 an OK to the Originating Exchange 301.

• Call is terminated by both parties

Concept of what hardware/software would be required to archive call termination

The Originating exchange needs to have the ability of intercepting the messaging and terminating the call based on the scenarios above.

An example of equipment that would be capable of archiving this would be telephony software running on industry standard computer hardware (server).

The telephony software could be an open source framework for building communications applications, such as Asterisk software.

The telephony software turns an ordinary computer into a communications server. The telephony software powers IP PBX systems, VoIP gateways, conference servers and more. It can be used by small businesses, large businesses, call centres, carriers and governments worldwide.

Hardware and Software Example

• Server Hardware: IBM System x3250 M3

• Operating System: Linux

• Telephony Software: Asterisk 10.2.0 - rc2

• Telephony Hardware: Digium TE 1211

The IBM server can be replaced with similar industry hardware. The Asterisk telephony software can also run on Mac OSX instead of Linux but most versions of Linux are open source and thus license fee free whereas each copy of Mac OSX will incur a license fee. Asterisk itself is open source and therefore licence fee free. Asterisk is also designed to integrate perfectly with Digium telephony hardware. Though technically possible to replace both the Asterisk software and the Digium hardware the price point and seamless functionality would be very difficult to match.

Concept for call termination by the remote end voicemail system (^"Figure 6) This pertains to the action to be taken by the Terminating Voicemail system. If a telephony voice call 601 is diverted to voicemail 602 the call will be terminated 605 by the Voicemail before the voicemail answers 604. It may have the option of playing a prompt 603 to inform the user of the pending action. The method will be protocol independent. The voicemail does not answer until the caller has waited (example 5 seconds) giving them time to hang up and not be charged.

Turning to figure 7 in which there is shown a flow diagram 700 illustrating the flow path for the TIO (terminating originating switch) version of the invention. The flow diagram, illustrates the typical flow path for operation of the TOl version of the invention as described previously above. An SS7 Network connection 701 to either the originating or terminating C.O.S. (Central Office Switch) 702. A Terminator 703 (TOl) connected to the C.O.S 702 by an SS7 Network connection. The C.O.S 702 is connectable to either or all of the following Cellular voice connection 704, Standard landline telephone 705, PABX and telephone extension 706, WIFI connected phone and computer 707 and Cellular broadband connected phone or computer 708.

Turning to figure 8 in which there is shown a flow diagram 800 illustrating the flow path for the T2D (terminating destination switch) version of the invention. The flow diagram, illustrates the typical flow path for operation of the T2D version of the invention as described previously above. An SS7 Network connection 801 to either the originating or terminating C.O.S. (Central Office Switch) 802. A Terminator 803 (TD2) connected to the C.O.S 802 by an SS7 Network connection. The C.O.S 802 is connectable to either or all of the following Cellular voice connection 804, Standard landline telephone 805, PABX and telephone extension 806, WIFI connected phone and computer 807 and Cellular broadband connected phone or computer 808.

Turning to figure 9 in which there is shown the user call flow path 900 of the invention.

To commence 901 the terminating system Customer of network operator or telco that offers service enters short code i.e. # 45 to initiate the Terminator service. Customer can suspend the service by entering short code i.e. # 46.

The customer dials number as per usual 902 upon which three things can occur, these being the called phone is switched off 903 or phone diverts on busy 904 or phone diverts on no reply 905. When the called phone is switched off 903 the caller either presses 1 or hangs up in 3 seconds 906 to avoid call charges 912 or press 2 or stay on the line 907 to leave a message 913.

When the called phone diverts on busy 904 the caller either presses 1 or hang up in 3 seconds 908 to avoid call charges 914 or press 2 or stay on the line 909 to leave a message 915.

When the called phone diverts on no reply 905 the caller either presses 1 or hang up in 3 seconds 910 to avoid call charges 916 or press 2 or stay on the line 91 1 to leave a message 917.

Advantages

• The invention allows users to avoid call diversion to voicemail services, and can therefore make significant savings on call costs.

• The Telephone user will save at least between 10% and 40% percent of their usual phone bill.

Variations

Throughout the description of this specification, the word "comprise" and variations of that word such as "comprising" and "comprises", are not intended to exclude other additives, components, integers or steps.

It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein described in the appended claims.

Claims

Claims:

Claim 1 : A communications system having a transit switch for forwarding telephony calls, wherein the transit switch includes detection means to detect whether a forwarding call is being diverted or is about to be diverted, and release means to release the call in response to the detection means detecting that the forwarded call is being diverted or is about to be diverted.

Claim 2: The communications system as claimed in claim 1, wherein the system disconnects the call before the diverted call is completed so that no call charge is made to the caller.

Claim 3 : The communications system as claimed in anyone of the preceding claims, wherein the system includes an originating exchange which forwards calls to a transit exchange, and the transit exchange forwards the calls to a destination exchange.

Claim 4: The communications system as claimed in claim 3, wherein the transit exchange includes the transit switch.

Claim 5: The communications system as claimed in anyone of claims 3 to 4, wherein the transit exchange may receive a signalling message from the destination exchange to detect when the call is being diverted or is about to be diverted.

Claim 6: The communications system as claimed in anyone of claims 3 to 5, wherein the transit exchange may send a message to the originating exchange to disconnect the call.

Claim 7: The communications system as claimed in anyone of the preceding claims, wherein the system includes messaging means to send a message to the destination telephone or communication device to which the call was directed after being disconnected following diversion being detected.

Claim 8: The communications system as claimed in claim 7, wherein the message may include an SMS message.

Claim 9: The communications system as claimed in anyone of the claims 7 to 8, wherein the message includes information regarding the caller's telephone number or the caller's identity. Claim 10: A method of processing a telephony call, wherein the method includes the steps of detecting when a call is being diverted, or is about to be diverted, and disconnecting the call before the diverted call is completed.

Claim 11 : The method of processing a telephony call as claimed in claim 10, wherein the step of disconnecting the call before the diverted call is completed results in no call charge being made to the caller.

Claim 12: The method of processing a telephony call as claimed in any one of claims 10 to 11, wherein the method includes the step of forwarding the call from an originating exchange to a transit exchange, and from the transit exchange to a destination exchange.

Claim 13: The method of processing a telephony call as claimed in claim 1 1, wherein the step of detecting when the call is being diverted or is about to be diverted includes the step of receiving a signalling message at the transit exchange from the destination exchange.

Claim 14: The method of processing a telephony call as claimed in claim 13, wherein the step of disconnecting the call includes the step of sending a message from the transit exchange to the originating exchange.

Claim 15: The method of processing a telephony call as claimed in any one of claims 10 to 14, wherein the method also includes the step of sending a message to the destination telephone or communication device to which the call was directed after the call has been disconnected following diversion being detected.

Claim 16: The method of processing a telephony call as claimed in claim 15, wherein the message may include an SMS message.

Claim 17: The method of processing a telephony call as claimed in any one of claims 15 to 16, wherein the message includes information regarding the caller's telephone number or the caller's identity.

Claim 18: A method of processing a telephony call, wherein the method includes the steps of sending an Initial Address Message to a transit switch, forwarding the Initial Address Message from the transit switch to its intended destination, detecting at the transit switch when a Call Progress Message indicative of call diversion is received, and sending a Release message from the transit switch to prevent the call being made to the diverted destination.

Claim 19: A method of preventing a telephony call from being diverted to a voicemail service, wherein the method includes the steps of directing the call to a transit switch, forwarding the call from the transit switch to its intended destination, detecting at the transit switch whether the call is being diverted or is about to be diverted, and releasing the call to prevent the call being made to the diverted destination.

Claim 20: A communications system as substantially hereinbefore described with reference to the accompanying drawings.

Claim 21 : A method of operating communications system as substantially hereinbefore described with reference to the accompanying drawings.

Claim 22: A method of processing a telephony call as substantially hereinbefore described with reference to the accompanying drawings.

Claim 23: A method of preventing a telephony call from being diverted to a voicemail service as substantially hereinbefore described with reference to the accompanying drawings.

PIPERS

Attorneys for the Applicant