Patent Publication Number: US-9854102-B2

Title: Systems and methods of providing communications services

Description:
This application is a continuation of U.S. application Ser. No. 13/730,348, filed Dec. 28, 2012, which is itself a continuation-in-part of application Ser. No. 13/244,872, filed Sep. 26, 2011, and a continuation-in-part of application Ser. No. 13/244,827, filed Sep. 26, 2011, now U.S. Pat. No. 8,265,083, both of which claim priority to the filing dates of Provisional Application No. 61/512,265, filed Jul. 27, 2011, and Provisional Application No. 61/529,742, filed Aug. 31, 2011. The contents of all of those applications are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention is related to Internet protocol (IP) telephony systems that allow users to place and receive telephone calls, and to send and receive text and video messages via data packets that are communicated over a data network. 
     Presently, there are many IP telephony systems that provide telephony services to their users. Typically, a user will register with an IP telephony system to obtain telephony services at their residence or business. As part of the registration process, one or more of the user&#39;s telephony devices in their home or business are registered with the IP telephony system. 
     When the user wishes to place a call or send a text or video message, the user&#39;s telephony device contacts a server or a gateway maintained by the IP telephony system over a public and/or private data network. The server or gateway then acts to provide the user with the requested communications services. 
     IP telephony systems can provide the same types of communications services as traditional telephony service providers that operate through a publically switched telephone network (PSTN), but at significantly lower costs. For this reason, many people have switched their residential and business telephony service provider from a traditional PSTN-based telephony services provider to an IP telephony service provider. 
     Many users also have a separate mobile or cellular telephone in addition to their residential and business telephones. Although it would be desirable to utilize an IP telephony service provider to obtain certain types of communications services on mobile telephones, doing so is often inconvenient. 
     Generally, the only way to place international long distance telephone calls through an IP telephony service provider using a mobile telephone is to pre-pay for an IP telephony service that is separate and distinct from the carrier that provides the regular native telephony service to the user&#39;s mobile telephone. Once the user has prepaid for a certain amount of minutes, in order to place a telephone call using the IP telephony service, the user must engage in a cumbersome dialing procedure. In order to use the IP telephony service, the user may need to remember a username or account number, as well as a PIN or password. 
     Thus, although it is possible to obtain lower cost IP telephony services on a mobile telephone, it is not convenient or quick to place calls through the service. Further, the user must engage in a separate financial transaction to obtain minutes of call time on the IP telephony service. Also, if the user has an account with an IP telephony service that is left with only a few minutes of talk time, the user may choose to not use the remaining minutes, meaning some of the money spent to acquire minutes of talk time on the IP telephony system will be lost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a communications environment including various elements which are associated with an Internet protocol (IP) telephony system operating in accordance with the invention; 
         FIG. 2  is a diagram of various elements of a processor that forms part of a IP telephony system; 
         FIG. 3  is block diagram illustrating selected elements of an IP telephony system that is capable of providing telephony services to a telephony device that is native to another telephony system; 
         FIG. 4  illustrates elements of a software application that may be present on an extension telephony device; 
         FIG. 5  is diagram illustrating steps of a method of providing telephony services to a telephone that is native to a first telephony system with elements of a second telephony system; 
         FIG. 6  is diagram illustrating steps of a method of assigning a local telephone number within a first country that a user within the first country can dial to be connected to a different telephone number in a second country; 
         FIG. 7  is a diagram illustrating steps of a method that would be performed by software running on a smartphone or a computer that is acting as an extension telephony device to place a telephone call; 
         FIG. 8  is a diagram illustrating steps of a method that would be performed by an extension operations unit of an IP telephony system to connect a smartphone or a computer acting as an extension telephony device to a called party; 
         FIG. 9  illustrates steps of a method performed by elements of an IP telephony system to establish a telephony communication for an extension telephony device; 
         FIG. 10  illustrates steps of a method performed by a software application on an extension telephony device to establish a telephony communication for an extension telephony device; 
         FIG. 11  illustrates steps of a method performed by elements of an IP telephony system to connect an extension telephony device to an ongoing telephony communication; 
         FIG. 12  illustrates steps of a method performed by an extension telephony device to join an ongoing telephony communication; 
         FIG. 13  illustrates steps of a method performed by elements of an IP telephony system to determine which calling party identifier to use in caller ID information; and 
         FIG. 14  illustrates steps of a method performed by a software application of an extension telephony device to determine which calling party identifier to use in caller ID information. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following detailed description of preferred embodiments refers to the accompanying drawings, which illustrate specific embodiments of the invention. Other embodiments having different structures and operations do not depart from the scope of the present invention. 
     The technology is related to telephony systems generally. The technology encompasses systems and methods of providing communications services to a user&#39;s telephony device that is native to a first telephony system through a second telephony system. Preferably, the second telephony system is an IP based telephony system and is distinct from the first telephony system. 
     In the following description, the terms VOIP, VOIP (Voice over IP) system, VOIP telephony system, IP system and IP telephony system are all intended to refer to a system that connects callers and that delivers data, text and video communications using Internet protocol data communications. 
     As illustrated in  FIG. 1 , a communications environment  100  is provided to facilitate IP enhanced communications. An IP telephony system  120  enables connection of telephone calls between its own customers and other parties via data communications that pass over a data network. The data network is commonly the Internet  110 , although the IP telephony system may also make use of private data networks. The IP telephony system  120  is connected to the Internet  110 . In addition, the IP telephony system  120  is connected to a first publicly switched telephone network (PSTN)  130  via a gateway  122 . The first PSTN  130  may also be directly coupled to the Internet  110  through one of its own internal gateways. Thus, communications may pass back and forth between the first IP telephony system  120  and the PSTN  130  through the Internet  110  via a gateway maintained within the PSTN  130 . 
     The gateway  122  allows users and devices that are connected to the PSTN  130  to connect with users and devices that are reachable through the IP telephony system  120 , and vice versa. In some instances, the gateway  122  would be a part of the IP telephony system  120 . In other instances, the gateway  122  could be maintained by a third party. 
     Customers of the IP telephony system  120  can place and receive telephone calls using an IP telephone  108  that is connected to the Internet  110 . Such an IP telephone  108  could be connected to an Internet service provider via a wired connection or via a wireless router. In some instances, the IP telephone  108  could utilize a cellular telephone system to access the Internet  110 . 
     Alternatively, a customer could utilize a normal analog telephone  102   a  which is connected to the Internet  110  via a telephone adapter  104 . The telephone adapter  104  converts analog signals from the telephone  102   a  into data signals that pass over the Internet  110 , and vice versa. Also, as illustrated in  FIG. 1 , multiple analog telephone devices  102   a ,  102   b  and  102   c  could all be coupled to the same telephone adaptor  104 . Analog telephone devices include but are not limited to standard telephones and document imaging devices such as facsimile machines. A configuration using a telephone adapter  104  is common where all of the analog telephone devices  102   a ,  102   b  and  102   c  are located in a residence or business, and all of the telephone devices are connected to the same telephone adapter. With this type of a configuration, all of the analog telephone devices  102   a ,  102   b ,  102   c  share the same telephone number assigned to the telephone adaptor  104 . Other configurations are also possible where multiple communication lines (e.g., a second telephone number) are provisioned by the IP telephony system  120 . 
     In addition, a customer could utilize a soft-phone client running on a computer  106  to place and receive IP based telephone calls, and to access other IP telephony systems (not shown). In some instances, the soft-phone client could be assigned its own telephone number. In other instances, the soft-phone client could be associated with a telephone number that is also assigned to an IP telephone  108 , or to a telephone adaptor  104  that is connected to one or more analog telephones  102 . 
     A third party using an analog telephone  132  which is connected to the PSTN  130  may call a customer of the IP telephony system  120 . In this instance, the call is initially connected from the analog telephone  132  to the PSTN  130 , and then from the PSTN  130 , through the gateway  122  to the IP telephony system  120 . The IP telephony system  120  then routes the call to the customer&#39;s IP telephony device. A third party using a cellular telephone  134  could also place a call to an IP telephony system customer, and the connection would be established in a similar manner, although the first link would involve communications between the cellular telephone  134  and a cellular telephone network. For purposes of this explanation, the cellular telephone network is considered part of the PSTN  130 . 
     In addition, mobile computing devices which include cellular telephone capabilities could also be used to place telephone calls to customers of the IP telephony system. A mobile computing device  136 , as illustrated in  FIG. 1 , might connect to the PSTN  130  using its cellular telephone capabilities. However, such devices might also have the ability to connect wirelessly via some other means. For example, a mobile computing device  136  might communicate with a wireless access point  138  which connects the mobile computing device  136  directly to a data network, such as the Internet  110 . In this instance, communications between the mobile computing device  136  and other parties could be entirely carried by data communications which pass from the mobile computing device  136  directly to a data network  110 . Of course, alternate embodiments could utilize any other form of wireless communications path to enable communications. 
     Users of the IP telephony system  120  are able to access the service from virtually any location where they can connect to the Internet  110 . Thus, a customer could register with an IP telephony system provider in the U.S., and that customer could then use an IP telephone  108  located in a country outside the U.S. to access the services. Likewise, the customer could also utilize a computer outside the U.S. that is running a soft-phone client to access the IP telephony system  120 . 
       FIG. 1  also illustrates that a second IP telephony system  140  may interact with the first IP telephony system  120  via the Internet  110 . For example, customers of the second IP telephony system  140  may place calls to customers of the first IP telephony system  120 . In that instance, assets of the second IP telephony system  140  interact with assets of the first IP telephony system  120  to setup and carry the telephone call. The same basic thing could happen if customers of the first IP telephony system  120  place calls to customers of the second IP telephony system  140 . 
       FIG. 1  also illustrates a second PSTN  150  that is coupled to an analog telephone  152  and a cellular telephone  154 . The second PSTN  150  may also be directly coupled to the Internet  110  through one of its own internal gateways. Thus, communications may pass back and forth between the first IP telephony system  120  and the second PSTN  150  through the Internet  110  via a gateway maintained within the second PSTN  150 . Calls from customers of the first IP telephony system  120  may be routed to the analog telephone  152  or the cellular telephone  154  through the second PSTN  154 . 
     For purposes of the following description, we will assume that the first PSTN  130  is located in a first country, and that the second PSTN  140  is located in a second country. Likewise, the analog telephone  132  and cellular telephone  134  coupled to the first PSTN  130  are located in the first country, whereas the analog telephone  152  and cellular telephone  154  coupled to the second PSTN  150  are located in the second country. 
       FIG. 2  illustrates elements of a computer processor  250  that can be used as part of the IP telephony system  120  to accomplish various functions. The IP telephony system  120  could include multiple processors  250  located at various locations in the system, along with their operating components and programming, each carrying out a specific or dedicated portion of the functions performed by the IP telephony system  120 . 
     The processor  250  shown in  FIG. 2  may be one of any form of a general purpose computer processor used in accessing an IP-based network, such as a corporate intranet, the Internet or the like. The processor  250  comprises a central processing unit (CPU)  252 , a memory  254 , and support circuits  256  for the CPU  252 . The processor  250  also includes provisions  258 / 260  for connecting the processor  250  to customer equipment, to service provider equipment, to an IP network or gateways, as well as possibly one or more input/output devices (not shown) for accessing the processor and/or performing ancillary or administrative functions related thereto. The provisions  258 / 260  are shown as separate bus structures in  FIG. 2 ; however, they may alternately be a single bus structure without degrading or otherwise changing the intended operability of the processor  250 . 
     The memory  254  is coupled to the CPU  252 . The memory  254 , or computer-readable medium, may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, flash memory or any other form of digital storage, local or remote, and is preferably of non-volatile nature. The support circuits  256  are coupled to the CPU  252  for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like. 
     A software routine  262 , when executed by the CPU  252 , causes the processor  250  to perform processes of the disclosed embodiments, and is generally stored in the memory  254 . The software routine  262  may also be stored and/or executed by a second CPU (not shown) that is remotely located from the hardware being controlled by the CPU  252 . Also, the software routines could also be stored remotely from the CPU. For example, the software could be resident on servers and memory devices that are located remotely from the CPU, but which are accessible to the CPU via a data network connection. 
     The software routine  262 , when executed by the CPU  252 , transforms the general purpose computer into a specific purpose computer that performs one or more functions of the IP telephony system  120 . Although the processes of the disclosed embodiments may be discussed as being implemented as a software routine, some of the method steps that are disclosed therein may be performed in hardware as well as by a processor running software. As such, the embodiments may be implemented in software as executed upon a computer system, in hardware as an application specific integrated circuit or other type of hardware implementation, or a combination of software and hardware. The software routine  262  of the disclosed embodiments is capable of being executed on any computer operating system, and is capable of being performed using any CPU architecture. 
     In the following description, references will be made to an “IP telephony device.” This term is used to refer to any type of device which is capable of interacting with an IP telephony system to complete a telephone call. An IP telephony device could be an IP telephone, a computer running IP telephony software, a telephone adapter which is itself connected to a normal analog telephone, or some other type of device capable of communicating via data packets. An IP telephony device could also be a cellular telephone or a portable computing device that runs a software client that enables the device to act as an IP telephone. Thus, a single device might be capable of operating as both a cellular telephone and an IP telephone. 
     Moreover, certain devices that are not traditionally used as telephony devices may act as telephony devices once they are configured with appropriate client software. Thus, some devices that would not normally be considered telephony devices may become telephony devices or IP telephony devices once they are running appropriate software. 
     The following description will also refer to telephony communications and telephony activity. These terms are intended to encompass all types of analog and video telephone calls, regardless of whether all or a portion of the calls are carried in an analog or digital format. These terms are also intended to encompass data communications that are conveyed through a PSTN or VOIP telephony system, such as facsimile transmissions, text messages, SMS messages, MMS messages, video messages, and all other types of data communications sent by or received by a user. In other words, these terms are intended to encompass any communications whatsoever, in any format, which traverse all or a portion of a communications network or telephony network. 
       FIG. 3  illustrates elements of an IP telephony system  120 . The IP telephony system  120  includes a call routing engine  230 . The call routing engine  230  provides instructions to servers of the telephony system  120  to help the servers establish communications channels between a calling party and a called party. The call routing engine  230  also helps servers to deliver text messages, SMS messages, MMS messages and other forms of communications. 
     The IP telephony system  120  further includes a billing system  240 . The billing system  240  uses information drawn from a call detail record (CDR) database  220 , and possibly other sources, to determine how much to bill the users of the IP telephony system  120 . 
     The IP telephony system  120  also includes a partner provider interface module  250 . This module communicates various items of information with partner providers who help to complete telephone calls for the IP telephony system  120  in various locations throughout the world. The same partner providers may deliver incoming calls directed to users of the IP telephony system  120 . In some instances, the partner providers may feed information about calls to the IP telephony system  120  via the partner provider interface module  250 . This information could be used by the IP telephony system  120  to create CDRs for user calls. 
     The IP telephony system  120  provides communications services to its registered users through telephony devices that the users have registered with the IP telephony system. For example, and with reference to  FIG. 1 , assume that a first user who has established an account with the IP telephony system  120  has registered the telephone adaptor  104  with the IP telephony system  120 . The IP telephony system  120  will have assigned a first telephone number to the first user&#39;s account, and calls to that telephone number will be routed to the telephone adaptor  104 . 
     Likewise, assume that a second user who has an account with the IP telephony system  120  has registered the IP telephone  108  with the IP telephony system  120 . The IP telephony system  120  will have assigned a second telephone number to the second user&#39;s account, and calls to that number will be routed to the IP telephone  108 . 
     In the following description, and the appended claims, the IP telephony system  120  may be referred to as a telephony system that provides “landline type” telephony services. This description is intended to distinguish the IP telephony system from a traditional cellular telephone services provider. However, this does not mean that the IP telephony system is incapable of providing telephony services to a mobile or cellular telephone. In fact, quite the opposite is true, as will be explained below. 
     Next, assume that the first user also possesses the cellular telephone  134 . The cellular telephone  134  is registered with a separate, first cellular telephony services provider. Also, assume that the second user possesses the mobile computing device with a cellular telephone  136 . The mobile computing device with a cellular telephone  136  is registered with a separate, second cellular telephony services provider. 
     An IP telephony system  120  as illustrated in  FIG. 3  is capable of providing communications services to a user through both the IP telephony device(s) that the user has registered with the IP telephony system  120 , and through a telephony device that is registered with and obtains its native telephony service from a separate telephony services provider. Thus, for example, the first user could obtain telephony services from the IP telephony system  120  using the first user&#39;s cellular telephone  134  that is registered with a first cellular telephony services provider. Likewise, the second user could obtain telephony services from the IP telephony system  120  using the mobile computing device  136  that is registered with a second cellular telephony services provider. Further, the IP telephony system  120  will bill the first and second users for telephone calls made using the cellular telephone  134  and mobile computing device  136  as part of their regular monthly bills from the IP telephony system  120 . 
     The IP telephony system  120  allows a user to register additional telephony devices that can act as “extensions” of the user&#39;s main IP telephony device(s). Thus, the first user can register his cellular telephone  134  as an extension telephony device. While incoming telephone calls directed to the first user&#39;s assigned telephone number will continue to be routed to the telephone adaptor  104 , the first user can place outgoing telephone calls through the IP telephony system  120  using his cellular telephone  134 , even though the first user&#39;s cellular telephone  134  is provided with its native telephony service by a separate cellular telephony services provider. This allows the first user to take advantage of the relatively low rates for long distance and international calls that are offered by the IP telephony system  120 . Those rates will typically be significantly lower than the rates the first user would be charged by the cellular telephony services provider. In addition, charges for calls made from the first user&#39;s cellular telephone  134  that are routed through the IP telephony system  120  will simply appear on the first user&#39;s regular monthly IP telephony system bill. 
     Likewise, the IP telephony system  120  allows the second user to register his mobile computing device  136  as an extension telephony device. While incoming telephone calls directed to the second user&#39;s assigned telephone number will continue to be routed to the second user&#39;s IP telephone  108 , the second user can place outgoing telephone calls though the IP telephony system  120  using his mobile computing device  136 , even though the second user&#39;s mobile computing device  136  is provided with its native telephone service by a separate cellular telephony services provider. 
     As illustrated in  FIG. 3 , the IP telephony system  120  includes an extensions operating unit  200 . The extensions operating unit  200  handles the registration of extension telephony devices, the setup and configuration of dialing aids, and the provisioning of telephony services to extension telephony devices. 
     An extension connection unit  202  is responsible for setting up calls for an extension telephony device. An authorization unit  204  is responsible for helping to register a telephony device as an extension of an existing account with the IP telephony system  120 . The authorization unit  204  is also responsible for determining if a registered extension telephony device is authorized to receive certain telephony services from the IP telephony system. 
     An extension speed dial unit  205  can provide speed dial functions for extension telephony devices. A local to international number assignment unit sets up special numbers that can be called in various countries to reach an extension telephony device. 
     A forwarding unit  208  operates to forward calls that are originally directed to a customer&#39;s main telephone number to an extension telephony device that is associated with the user&#39;s account. 
     A quality checking unit  210  checks a quality of a data connection that is established between the IP telephony system  120  and an extension telephony device via a data network. Calls may be connected to an extension telephony device in various different ways depending on the determined connection quality. 
     When a user wishes to register a telephony device as an extension telephony device, the actual registration process could be handled by the authorization unit  204  in multiple different ways. In some instances, a user could utilize a website interface to register a telephony device that receives its native telephony service from a different telephony service provider as an extension telephony device. In other instances, the user could call a special access number maintained by the IP telephony system  120 . This would connect the user to an interactive voice response system that would allow the user to register the extension telephony device. In other instances, a user could call and speak to a customer service representative that would assist with the registration of the extension telephony device. 
     It still other instances, such as where the extension telephony device is a mobile computing device, the user can download a software application onto the mobile computing device, and the software application can handle the registration of the mobile computing device as an extension telephony device. The application might also provide a user interface that allows the user to place telephone calls from the mobile computing device through the IP telephony system  120 . 
       FIG. 4  illustrates elements of a software application or client  400  that could be loaded onto an extension telephony device. The software client  400  includes a call connection unit  402  which establishes calls through the IP telephony system  120 . A configuration unit  404  records certain preferences that the user has selected. As will be explained in greater detail below, those preferences can include preferences about how calls are connected, and references relating to the information that is presented to a called party in caller ID information. The software client also includes a quality checking unit  406 , which determines a quality of a connection that an extension telephony device is able to establish with the IP telephony system  120  over a data network, or a quality of a connection to a wireless access point, or both. 
     Regardless of how it is accomplished, during the registration process the IP telephony system  120  obtains a telephone number or some other unique identifier associated with the extension telephony device. In addition, the authorization unit  204  may assign a unique personal identification number (PIN) to the extension telephony device. The user may be asked for the PIN when the user requests services through the IP telephony system  120 . In other instances, the same PIN associated with the user&#39;s main account with the IP telephony system  120  might be used to authorize the provision of communications services to the user through the extension telephony device. 
     With reference to the communications environment illustrated in  FIG. 1 , the first user, whose primary IP telephony device is the telephone adaptor  104 , would register his cellular telephone  134  as an extension telephony device. During the registration process, the authorization unit  204  obtains the telephone number associated with the cellular telephone  134 . The authorization unit may also assign a PIN number that the user can provide when requesting communications services from the IP telephony system  120  through the cellular telephone  134 . 
     Likewise, the second user would register his mobile computing device  136  as an extension telephony device. During the registration process, the authorization unit  204  could obtain a telephone number associated with the mobile computing device  136 , or a unique identification number assigned to the mobile computing device  136 , or both. Here again, the authorization unit  204  may assign a PIN number to the mobile computing device  136  that the second user would provide to obtain communications services from the IP telephony system  120  through the mobile computing device  136 . 
     The IP telephony system  120  may allow a user to register one or a predetermined number of extension telephony devices without charge. Any calls placed from the extension telephony device(s) would then incur the same charges as calls made from the user&#39;s primary IP telephony device. If the user places a call with an extension device to a telephone number that is part of an unlimited calling plan, no additional charges would apply. If a call is placed with an extension telephony device to a telephone number that would incur a per minute charge, the same rate applies to calls made from the extension telephony device that would apply to calls made from the user&#39;s primary IP telephony device. 
     If the user wants to register additional extension telephony devices beyond the number that can be registered for free, the IP telephony system  120  may charge the user a monthly re-occurring charge for each additional extension device. Paying the monthly re-occurring charge would then entitle the user to obtain communications services through the extension telephony device at the same rates the user would be charged for communications services provided to the user through his primary IP telephony device. Alternatively, the user may be provided with the option of registering additional extension telephony devices without the need to pay a monthly re-occurring charge if the user instead pays per minute fees for calls placed from the additional extension telephony devices. 
     Also, the IP telephony system  120  could offer the user different pricing options for communications services provided to the user through an extension telephony device than for communications services provided to the user through the user&#39;s primary IP telephony device. Regardless, the user would continue to receive one monthly bill for charges incurred for communications services provided to the user through the user&#39;s primary IP telephony device and through the user&#39;s extension telephony devices. 
     The IP telephony system  120  could also allow a master account holder to specify a maximum allowable monthly spending limit for each extension telephony device. The master user could set and change those spending limits by interacting with the authorization unit  204  via a web portal, through an interactive voice response system, or using an application loaded on a mobile computing device. Alternatively, the master user could speak with a customer service representative to have the maximum spending limits set or changed. 
     When a user wishes to place a call from an extension telephony device via the IP telephony system  120 , the call could be established in any of multiple different ways. 
     If the extension telephony device has a software client provided by the IP telephony system, and the extension telephony device is able to establish a data connection to a data network, such as the Internet, via a wireless access point, the call can be established without making use of the extension telephony device&#39;s native telephony service. Instead, the software client contacts the extension connection unit  202  of the IP telephony system  120  over the data network to request the setup of a call. The extension connection unit  202  then sets up a VOIP session to the extension telephony device over the data connection, and places an outgoing call to the requested party. The two calls are then effectively bridged together. 
     In instances where a software client on an extension telephony device cannot establish a data connection to the extension connection unit  202  of the IP telephony system  120  via a wireless access point, it may nevertheless be possible to establish the data connection via a cellular data service provided by the extension telephony device&#39;s native telephony service provider. In that case, the extension connection unit could still set up a VOIP session to the extension telephony device over the cellular data connection, and place an outgoing call to the requested party. The two calls are then effectively bridged together. 
     In instances where a software client on an extension telephony device cannot establish a data connection to the extension connection unit  202 , or in instances where the extension telephony device does not have the ability to run a software client, it is still possible to setup a call through the IP telephony system  120 . This is accomplished by placing a call to an access telephone number maintained by the IP telephony system. The call could be placed using the extension telephony device&#39;s native telephony service provider. Once connected to the IP telephony system  120 , the extension telephony device can request that the IP telephony system  120  place an outgoing call that is connected to the extension telephony device. This type of a connection method is illustrated in  FIG. 5 . 
       FIG. 5  illustrates the steps of a method  500  that would be performed by elements of the IP telephony system  120  to setup an outgoing call from an extension telephony device. The user places a call to a local access telephone number or to a toll free access number from a registered extension telephony device. The method begins and proceeds to step S 502 , where the call is received by the extension connection unit  202  of the IP telephony system  120  illustrated in  FIG. 3 . 
     The extension connection unit  202  obtains the telephone number of the extension telephony device through the caller ID information provided as part of the incoming call. In some instances, the extension connection unit  202  may obtain a unique ID number associated with the extension telephony device, or the extension connection unit  202  may request the user to input a unique identification number. The telephone number or unique identification number associated with the extension telephony device will be recognized because the user will have already registered the extension telephony device. 
     In step S 504 , the extension connection unit  202  asks the user to provide a PIN that is associated with the extension telephony device, or with the user&#39;s main account with the IP telephony system. This information could be provided to the extension connection unit in multiple different ways. It could be provided by the user pressing buttons on a keypad of the extension telephony device. Alternatively, the user might speak the information. In other instances, such as where an application is running on a mobile computing device, a query could be sent to an application running on the device, and the application could automatically provide the PIN information without further user intervention. Regardless, the extension connection unit  202  would acquire the information, and/or interpret any spoken responses using speech recognition assets. 
     In alternate embodiments, the provision of a PIN is not required. Instead, the caller ID information is used to verify the identity of the party. 
     In step S 506 , the extension connection unit  202  verifies that the calling party is authorized to place a call through the IP telephony system  120  using the extension telephony device. This would likely include interacting with the authorization unit  204  to verify that the obtained telephone number/unique identification number of the extension telephony device and the obtained PIN information match the information stored in the authorization unit  204 . 
     Assuming the obtained information is verified, and the user is authorized to place a call through the IP telephony system  120  with the extension telephony device, in step S 508  the extension connection unit  202  obtains the telephone number the user would like to call. This could occur in multiple different ways. 
     In a simple embodiment, the extension connection unit  202  prompts the user for the telephone number, and the user enters the telephone number using a keypad of the extension telephony device. The user might also speak the number, and the extension connection unit  202  would utilize speech recognition assets to interpret the user&#39;s spoken response. 
     In other instances, the user might be able to access a speed dial system that has been created for the user&#39;s main account with the IP telephony system  120 , or which has been specifically created for the extension telephony device. For example,  FIG. 3  illustrates that an extension speed dial unit  205  may be a part of the extension operations unit  200  of the IP telephony system  120 . 
     A user could configure the extensions speed dial unit  205  so that multiple pre-stored telephone numbers correspond to predetermined numbered options for each extension telephony device. When a user calls a local access number with an extension telephony device, the extension connection unit  202  will determine the identity of the extension telephony device. The user could make a telephone number selection from the predetermined list maintained for that extension telephony device in the extension speed dial unit  205 . 
     In more complex embodiments, the access number that was originally dialed by the user may be tied to a particular destination telephone number. If that is the case, then simply by virtue of the access number dialed by the user, the extension connection unit  202  will know what telephone number the user is attempting to reach. This concept is discussed in more detail below. 
     If the user is reaching the extension connection unit  202  from a mobile computing device that is running an application provided by the IP telephony system  120 , the application may allow the user to easily select a telephone number from a contact list maintained on the mobile computing device. The application would then forward the telephone number on to the extension connection unit  202 . 
     Once the extension connection unit  202  has obtained the telephone number the user wishes to reach, in step S 510  the extension connection unit  202  causes a telephone call to be setup to the desired telephone number using normal IP telephony system assets, as is well known to those of ordinary skill in the art. In some instances, the telephone call will be established such that the called party telephony device receives caller ID information identifying the extension telephony device as the calling party. In other instances, the caller ID information may reflect the telephony number associated with the user&#39;s main account with the IP telephony system as the calling party. These options are discussed in greater detail below. 
     The IP telephony system  120  will create a CDR for the call, and the CDR will be updated, finalized and stored at the completion of the call. The CDR will later be used to bill the user for the call placed through the extension telephony device. For this reason, the CDR may include a field that indicates that the call was placed through a particular registered extension telephony device. 
     Once the call has been setup by the IP telephony system  120 , the server that originally establishes the call may conduct an optional call transfer in step S 412 . The call transfer would allow the call signaling to proceed more directly between the extension telephony device and the called telephony device. When a call transfer is conducted, it would free up assets of the IP telephony system  120  for other uses. 
     In some embodiments, the user&#39;s extension telephony device may be a mobile computing device that is running an application provided by the IP telephony system  120 . In such an embodiment, once a call is established to the extension connection unit  202 , the application may send information to the extension connection unit that includes the telephone number of the extension telephony device, a unique identifier assigned to the user&#39;s extension telephony device, and/or a PIN number. Thus, a software application on an extension telephony device could automate the performance of certain steps illustrated in  FIG. 5 . 
     As mentioned above, in some embodiments, the IP telephony system  120  can assign a local access number for a user to correspond to a number that the user frequently calls from his extension telephony device. For purposes of explanation, and with reference to  FIG. 1 , assume that the first user frequently uses his cellular telephone  134  to call his mother, who has analog telephone  152  in a different country. The first user has already registered his cellular telephone  134  as an extension telephony device with the IP telephony system  120 . The first user can request that the IP telephony system assign a local access number to correspond to the telephone number assigned to his mother&#39;s analog telephone  152 . Steps of a method to accomplish this assignment are illustrated in  FIG. 6 . The steps illustrated in  FIG. 6  would be performed by elements of the IP telephony system  120 . 
     The method  600  begins when the first user requests that a local access number be assigned to his mother&#39;s telephone number. This request would be received by the local to international telephone number assignment unit  206  of the extensions operation unit  200  of the IP telephony system  120 , as shown in  FIG. 3 . The first user could interact with the local to international telephone number assignment unit  206  in multiple different ways. The first user could utilize a web interface, an interactive voice response system available through an access number, or the first user could speak with a customer service representative. If the first user&#39;s extension telephony device is a mobile computing device, an application running on the mobile computing device could also be used to interact with the local to international telephone number assignment unit  206 . 
     The method begins and proceeds to step S 602 , where the local to international telephone number assignment unit  206  receives the request from the first user. In step S 604 , the local to international telephone number assignment unit  206  obtains the telephone number the first user wishes to be assigned, which in this case is the telephone number of his mother&#39;s analog telephone  152 . The local to international telephone number assignment unit  206  also obtains the identity of the party at that telephone number, in this case, the first user&#39;s mother. In step S 606 , the local to international telephone number assignment unit  206  assigns a local access number that the first user can call to be connected to his mother&#39;s analog telephone  152 . This number is ideally one that the first user can call from his extension telephony device without incurring any long distance or toll charges. 
     In step S 608 , the local to international telephone number assignment unit  206  initiates an outbound call to the first user&#39;s extension telephony device. The call will indicate that it has originated from the assigned local access number, and it will indicate that the call is from the first user&#39;s mother. When this information is captured by the first user&#39;s extension telephony device, it is easy for the first user to store this information in a contact list on the first user&#39;s extension telephony device. Thus, the local access number is communicated to the first user in an easy and convenient manner. In step S 610 , the outbound call is then terminated. 
     Once this process has been conduced, the first user can simply call the assigned local access number. When the call is received by the extension connection unit  202 , the extension connection unit  202  will know both the local access number that was called, and the telephone number or ID number of the first user&#39;s extension telephony device. This will allow the extension connection unit  202  to determine the number that the first user wishes to call. The extension connection unit  202  may then ask the first user for the PIN number assigned to the first user&#39;s extension telephony device to ensure that the user&#39;s is authorized to make the call through the IP telephony system. As soon as the user provides the PIN, the call would be connected. In some embodiments, obtaining the PIN may not occur. In still other embodiments, a software application on the user&#39;s extension telephony device may automatically provide the PIN. 
     As mentioned above, in some instances a user could place a call from an extension telephony device that is a smartphone or a computer or a portable computing device running appropriate software. In these instances, some or all of the communications required to inform the extension operation unit  200  of the called party&#39;s telephone number, the user&#39;s account information and a PIN number can be automated by the software. The software might also make it easier for the user to input or select a telephone number of the party the user is attempting to reach. 
       FIG. 7  illustrates steps of a method  700  that would be performed by an application on a smartphone or software on a computer in order to place a call while the smartphone or computer is acting as an extension telephony device.  FIG. 8  illustrates steps of a method  800  that would be performed by the extensions operation unit  202  of an IP telephony system  120  to connect such an extension telephony device to a called party. In the following description, we will assume that the user is placing a call from a smartphone that is registered as an extension telephony device under a user&#39;s main account with an IP telephony system  120 . However, the same basic steps would be performed if the user was placing a call from a computer or a portable computing device that is acting as an extension telephony device. 
     The method begins when a user decides to place a call using a smartphone as an extension telephony device. The user loads and runs an application on the smartphone that automates many of the steps the user would otherwise have to perform under the methods described above. The method begins and proceeds to step S 702 , where the application receives an indication from the user as to who the user wishes to call. This could be accomplished in many different ways. The user could simply type in the number the user wishes to call on a keypad of the smartphone. Alternatively, the application could cause a keypad to be displayed on a touch sensitive display screen on the smartphone, and the user could enter the telephone number using the displayed keypad. In still other instances, the application could present the user with a list of contacts, and the user could select one of the contacts from the list. In this instance, the contact list could be a contact list that is stored on the smartphone through another separate application, or a contact list that has been input and maintained on the smartphone using the application that has been run by the user to place a call using the smartphone as an extension telephony device. The actual data that constitutes the contact list could be stored on the smartphone itself, or it could be stored on a remote server that the smartphone is able access via a data connection. 
     Once the application has obtained the telephone number of the called party, in step S 704 , the application establishes a data link with the extension connection unit  202  of the extension operations unit  200  of the IP telephony system  120 , as illustrated in  FIG. 3 . This data link could be established using a cellular data channel or via a wireless or wired link to a public or private data network, such as the Internet. Regardless of how the data link is established, the data link allows the application on the user&#39;s smartphone to communicate with a server that is part of the extension connection unit  202 . 
     In step S 706 , the application informs the extension connection unit  202  of the called party&#39;s telephone number. The application may also provide the extension connection unit  202  with the telephone number of the user&#39;s smartphone, or a special identification number assigned to the user&#39;s smartphone or to the application running on the user&#39;s smartphone. This information will allow the extension connection unit to identify the user&#39;s smartphone as a registered extension telephony device. 
     The application may also automatically provide the extension connection unit  202  with a PIN number that was assigned to the user or to the user&#39;s smartphone or to the application loaded on the smartphone. The PIN number is used to verify the identity of the user or the smartphone for purposes of fraud prevention. In alternate embodiments, the application may require the user to enter or speak the PIN number, which would be another way of preventing an unauthorized user from placing a telephone call using someone else&#39;s smartphone. 
     In step S 708 , the application obtains a telephone number from the extension connection unit  202 . Then, in step S 710 , the application causes the smartphone to call the telephone number it received from the extension connection unit  202 . As will be explained in greater detail below, the user would then be connected to the called party. 
     Although the embodiment illustrated in  FIG. 7  ultimately connects the user to the called party through a telephone call placed to the telephone number obtained from the extension connection unit  202 , in alternate embodiments, the user may be connected to the called party in some other fashion. For example, the data link established between the user&#39;s smartphone and the extension connection unit  202  could be used to establish a VOIP call to the called party. In other instances, the application on the user&#39;s smartphone may establish a VOIP call to the called party in some other fashion, with the assistance of the extension connection unit  202 . 
       FIG. 8  illustrates steps of a method  800  performed by the extension operations unit  200  of the IP telephony system  120  to connect a smartphone running an application and acting as an extension telephony device to a called party. The method  800  begins and proceeds to step S 802 , where the extension connection unit  202  receives a communication from the application on the user&#39;s smartphone indicating that the application is attempting to place a call to a called party. In step S 802 , the extension connection unit  202  establishes a data link with the application on the smartphone. As noted above, this data link could be established in multiple different ways. 
     In step S 804 , the extension connection unit  202  receives several pieces of information from the application on the user&#39;s smartphone. First, the extension connection unit  202  receives either the telephone number of the user&#39;s smartphone or an identification number that was assigned to the user&#39;s smartphone or to the application running on the user&#39;s smartphone. This information is used to verify the identity of the user and to verify that the smartphone is a registered extension telephony device. The telephone number of the user&#39;s smartphone may also be used for caller ID purposes when the call is placed to the called party. 
     The extension connection unit  202  also receives the telephone number of the called party that the user is attempting to reach. The extension connection unit  202  may also automatically receive a PIN number from the application on the user&#39;s smartphone. Alternatively, the application may request that the user input a PIN number, and that information may then be provided to the extension connection unit  202 . In still other embodiments, the extension connection unit  202  may send a query to the user, via the application on the user&#39;s smartphone, asking the user to input a PIN number. In some embodiments, the user may have the option of speaking the PIN number. In those embodiments, the application on the smartphone may interpret this spoken response, or the extension connection unit  202  may receive the audio of the spoken response, and the extension connection unit  202  may be responsible for interpreting the spoken response. In still other embodiments, a PIN may not be required. Instead, the user&#39;s identity may be verified using caller ID information. 
     In step S 806 , the extension connection unit  202  verifies that the user is authorized to place the requested call. This would likely include interacting with the authorization unit  204  to verify that the obtained telephone number/unique identification number of the smartphone and the obtained PIN information match the information stored in the authorization unit  204 . 
     If the user is authorized to place the requested call, in step S 808 , the extension connection unit  202  provides the application on the user&#39;s smartphone with a telephone number that the smartphone can call to be connected to the called party. At this point, the application on the user&#39;s smartphone will place a call to the telephone number obtained from the extension connection unit  202 , as described above in connection with  FIG. 6 . 
     In step S 810 , the extension connection unit  202  receives the incoming call from the user&#39;s smartphone. The extension connection unit  202  recognizes the user&#39;s smartphone through caller ID information, and the extension connection unit  202  will already know, from the previous information exchange with the application on the smartphone, what telephone number the user is attempting to call. In step S 812 , the extension connection unit  202  places an outgoing call to the called party, and in step S 814 , the extension connection unit  202  bridges the incoming and outgoing calls so that the user&#39;s smartphone is connected to the called party. 
     In some embodiments, the extension connection unit  202  waits to receive the incoming call from the user&#39;s smartphone before placing the outgoing call to the called party. In other instances, the extension connection unit begins to setup the outgoing call after it receives the called party&#39;s telephone number from the application on the user&#39;s smartphone and before it receives the incoming call from the user&#39;s smartphone. This would result in a faster connection for the user. 
     As noted above, in alternate embodiments, the user&#39;s smartphone may be connected to the called party in a different fashion. For example, because the extension connection unit  202  receives all required relevant information from the application on the user&#39;s smartphone via the initial data connection, the extension connection unit  202  may setup a VOIP call to the called party, and that call may be bridged to the user&#39;s smartphone using the same data connection that was used to receive information from the application on the user&#39;s smartphone. This would eliminate the need for the application to place a separate call to the telephone number provided by the extension connection unit  202 . 
     The application on a user&#39;s smartphone, or software running on a computer or portable computing device, may provide additional functionality beyond merely allowing the user to place a call. For example, the software may also allow a user to perform a rate lookup to determine how much it will cost to place a particular call. The application may also allow a user to access his account information with the IP telephony system, and also edit or update that information. The application may also allow a user to place a text message to particular telephone number using the smartphone or computer as an extension telephony device. 
     In the examples given above, it was assumed that the user would already have an existing account with the IP telephony system, and that the user would have already registered a primary IP telephony device with the IP telephony system. In alternate embodiments, it is not necessary for a user to have a separate primary IP telephony device. Instead, a user would setup a new account with the IP telephony system with the intention of only registering a telephony device that is already registered with and provided service by a separate telephony service provider. This would allow the user to place calls from the telephony device using the native telephony service provider, or through the IP telephony system. In many instances, the IP telephony system may be able to provide the user with communications services at lower rates than the native telephony service provider would charge. 
     Also, in the examples given above, the user places a telephone call using an extension telephony device. However, the same basic procedures would be used if a user wishes to obtain other types of communications services from the IP telephony system via an extension telephony device. For example, the user could send SMS text messages, MMS messages and other forms of communications through the IP telephony system from an extension telephony device. 
     As explained above, in many instances, an application on a smartphone or computer that is acting as an extension telephony device can establish a data connection to the extension connection unit  202 . The data connection can be used to establish a VOIP link to the extension telephony device. That VOIP link can be used to establish an outgoing call from the extension telephony device, or to receive an incoming call. However, conducting a good quality call in this fashion requires that the quality of the data connection between the extension telephony device and the extension connection unit  202  be sufficiently high to support a VOIP call. 
       FIG. 9  illustrates steps of a method  900  that would be performed by elements of an extension connection unit  200  to setup a call for an extension telephony device. During this method, the quality of a data connection between the extension operations unit  200  and the extension telephony device is determined during an initial exchange. The call is then setup based on the determined quality. 
     The method  900  begins and proceeds to step S 902  where the extension connection unit  202  receives a request from a registered extension telephony device to setup a new telephony communication. In step S 904 , a quality checking unit  210  of the extension operations unit checks the quality of a data connection between the extension operations unit  200  and the extension telephony device. This could be accomplished by monitoring how well data packets bearing the setup request were communicated from the extension telephony device to the extension operations unit  200 . Also, when the setup request is received, the extension connection unit  202  could send an acknowledgement message back to the extension telephony device. The determination about the quality of the data connection could also be based on how well data packets bearing the acknowledgement message were communicated from the extension connection unit  202  to the extension telephony device. 
     In step S 906 , a check is performed to determine if the quality of the data connection between the extension telephony device and the extension operations unit  200  is sufficiently high to support a VOIP call. If so, the method proceeds to step S 908 , and a VOIP link is established between the extension connection unit  202  and the extension telephony device. That VOIP link is used for the outgoing call. If the check performed in step S 906  indicates that the quality of the data connection is not sufficiently high to support a VOIP call, the outgoing call is established using the extension telephony device&#39;s native telephony service. In either case, the call can be established as explained above. 
     In alternate embodiments, the check of the quality of the data connection could be performed before a user actually requests that a call be established. For example, the quality check could be performed on a periodic basis. When quality checks are performed on a periodic basis, so long as the last quality check was performed relatively recently, a call could be established immediately upon user request. 
     Also, in some embodiments, a quality check is performed upon the occurrence of a triggering event. A triggering event could be when a mobile telephony device establishes a new data connection or switches a cellular connection from one base station to another. Other triggering events could include switching a WiFi transceiver on, switching a cellular transceiver on, or simply turning the telephony device on. 
       FIG. 10  illustrates steps of a method  1000  that are performed by a software application  400  on the extension telephony device to accomplish this operation. The method  1000  begins and proceeds to step S 1002 , where a call connection unit  402  of the software application  400  sends a communication setup request to the extension connection unit  202  over a data connection. In step S 1004 , a quality checking unit  406  of the software application  400  checks the quality of the data connection. As mentioned above, this could include monitoring how well data packets bearing the setup request are communicated to the extension connection unit  202  and/or how well data packets bearing an acknowledgement message are communicated from the extension connection unit  202  back to the extension telephony device. In addition, the quality checking unit  406  of the software application  400  may also check a quality of a connection that has been established between the extension telephony device and a wireless access point that provides the extension telephony device with access to a data network. This information could be used alone, or together, with information about how well data packets are being communicated back and forth between the extension telephony device and the extension connection unit  202 . 
     In step S 1006 , a check is performed to determine if the quality of the data connection between the extension telephony device and the extension operations unit  200  is sufficiently high to support a VOIP call. If so, the method proceeds to step S 1008 , and a VOIP link is established between the extension connection unit  202  and the extension telephony device. That VOIP link is used for the outgoing call. If the check performed in step S 1006  indicates that the quality of the data connection is not sufficiently high to support a VOIP call, the outgoing call is established using the extension telephony device&#39;s native telephony service. In either case, the call can be established as explained above. 
     The methods illustrated in  FIGS. 9 and 10  ensure that the quality of an outgoing call from an extension telephony device remains high. Where the data network can be used to carry the call, it is used to avoid making use of the extension telephony device&#39;s native telephony service. This can minimize charges that the user must pay for use of the extension telephony device. 
     In the above methods, the data network connection that is established between the extension telephony device and the extension operations unit  200  of the IP telephony system could be a data connection that is established through a wireless access point. Alternatively, the data connection could be one established through a cellular data link that is provided as part of the extension telephony device&#39;s native telephony service. 
     The software application  400  on an extension telephony device includes a configuration unit  404 , which can record various user preferences. One such user preference is how calls to the extension telephony device are to be established. For example, the user could specify that the extension telephony device is not to establish an outgoing call through the IP telephony system  120  unless it can be accomplished via a data connection established through a wireless access point. This would prevent the software application from setting up a call through the IP telephony system using the extension telephony device&#39;s native telephony service. 
     Alternatively, the user could specify that calls through the IP telephony system can be established via a data connection through a wireless access point, or via a cellular data channel provided as part of the extension telephony device&#39;s native telephony service. This would prevent the software application  400  from setting up a call using minutes of a calling plan that is part of the extension telephony device&#39;s native telephony service. 
     The user may also specify that any type of connection could be used to establish a call through the IP telephony system  120 . This would give the software application  400  maximum flexibility to setup the call using the channel that provides the best quality. However, the user may still specify a preference about which channel is used. 
     As mentioned above, a registered extension telephony device is intended to be an extension of the user&#39;s basic telephony service provided by the IP telephony system  120 . As such, it is also desirable to use an extension just like a normal extension telephone that is present in a user&#39;s residence or office. In other words, it is desirable to be able to use both the user&#39;s primary registered telephony device and an extension telephony device in parallel, at the same time to allow multiple parties to be connected to the same incoming or outgoing telephony communication. For example, if a user received an incoming telephone call in the user&#39;s residence, and the user answered the call with the user&#39;s primary telephony device associated with the user&#39;s account, it would be desirable to allow a second person to connect to that telephony communication using the extension telephony device. 
       FIG. 11  illustrates steps of a method  1100  that would be performed by elements of an IP telephony system to connect an extension telephony device to an ongoing telephony communication that has been established to the main telephony device registered for the user&#39;s account with an IP telephony system  120 . The ongoing telephony communication could be an outgoing call or an incoming call. 
     The method  1100  begins and proceeds to step S 1102 , where the extension connection unit  202  of an extension operations unit  200  of an IP telephony system  120  receives a request from an extension telephony device to join an ongoing telephony communication that has been established to a main telephony device that is associated with the user&#39;s account with the IP telephony system  120 . The request could be received from a software application on the extension telephony device via a data network connection. 
     In step S 1104 , the extension connection unit  202  establishes a telephony connection to the extension telephony device. This could be a VOIP link established over a data connection, or a telephone link established over the native telephony service of the extension telephony device. Any of the methods described above could be used to establish the telephony link between the extension connection unit  202  and the extension telephony device. 
     In step S 1106 , the telephony link to the extension telephony device is effectively bridged to the ongoing telephony communication that has been established for the primary telephony device registered for the user&#39;s account. As a result, the user of the extension telephony device will be able to participate in the call. This type of a bridge arrangement essentially resembles a conference call. 
     If the user of the primary telephony device associated with the account hangs up, the telephony communication may continue between the user of the extension telephony device and the third party. Alternatively, the termination by the primary telephony device may act to terminate the call with respect to all parties. 
       FIG. 12  illustrates steps of a method  1200  that would be performed by the software application on an extension telephony device to accomplish the same operations. The method  1200  begins and proceeds to step S  1202 , where the software application sends a request to join an ongoing telephony communication to the extension connection unit  202 . In step S 1204 , the software application would act to establish a telephony link between the extension telephony device and the extension connection unit  202  using any of the methods which have been described above. Assuming the telephony link is established, the extension connection unit  202  would then bridge the telephony link to the ongoing telephony communication so that the user of the extension telephony device can join the ongoing telephony communication. 
     In order for the user of the extension telephony device to join an ongoing telephony communication that has been established for the primary telephony device associated with the account, the user of the extension telephony device must first be made aware of the existence of the telephony communication. This could occur because the user of the extension telephony device is co-located with the user of the primary telephony device. Alternatively, each time that a call is established for the primary telephony device, a message could be sent to the software application on the extension telephony device that notifies of the existence of the telephony communication. The message could include information about the identity of the third party to the communication. The software application could use this message and information to provide a notification to the user about the telephony communication, and the software application could ask the user if the user wishes to join the telephony communication. If the user responds affirmatively, the methods illustrated in  FIGS. 11 and 12  would then be performed. 
       FIG. 3  illustrates that the extension operations unit  200  includes a forwarding unit  208 . The forwarding unit  208  could act to forward telephony communications that are directed to the telephone number of the primary telephony device associated with an account to one or more extension telephony devices associated with the account. The user could make use of a web interface, an interactive voice response system or the user could interact with a customer service agent to configure how and when telephony communications are to be forwarded to an extension telephony device. The forwarding could be automatically activated and deactivated based on the user&#39;s preferences. 
     For example, the user could specify that during business hours, all telephony communications directed to the user&#39;s primary telephony device in the user&#39;s residence are to be forwarded to a mobile telephone which is registered as an extension telephony device. Alternatively, the user could specify that during non-business hours, telephony communications directed to a primary telephony device in the user&#39;s office are to be forward to a mobile telephony device that is registered as an extension telephone device. Any other sort of preferences could also be followed to automatically forward telephony communications to an extension telephony device. 
     If a user has multiple extension telephony devices, the user could specify that any forwarded communications are to be forwarded to all extension telephony devices simultaneously, or that the extension telephony devices are to be rung in a particular order until one of the extension telephony devices answers. 
     When a user places an outgoing call from an extension telephony device, the caller ID information that is sent to the called party could reflect any of several different calling party identifiers. The caller ID information could include a calling party identifier associated with the extension telephony device itself, such as the telephone number of the extension telephony device as established by the extension telephony device&#39;s native telephony service provider. Alternatively, the caller ID information could include a calling party identifier of a primary telephony device associated with the user&#39;s account with the IP telephony system. 
     A user of an extension telephony device could record a preference about which calling party identifier is to be used in the configuration unit  404  of a software application  400  on the extension telephony device. Alternatively, such a preference could be recorded in an element of the extension operations unit  200 . In still other embodiments, a user may be queried each time that an outgoing call is placed from the extension telephony device, the query asking the user to specify which calling party identifier is to be reflected in caller ID information sent to the called party. 
       FIG. 13  illustrates steps of a method  1300  that would be performed by elements of an extension operations unit  200  of an IP telephony system  120  when an outgoing call is to be established for an extension telephony device. The method would begin and proceed to step S 1302 , where the extension connection unit  202  receives a communication setup request from an extension telephony device. In step S 1304 , the extension connection unit determines which calling party identifier to use in caller ID information that is to be sent to the called party. The determination could be made by consulting preferences that have been stored in the extension operations unit. Alternatively, the extension connection unit  202  could query a software application on the extension telephony device to determine which calling party identifier to use. In still other instances, the calling party identifier that is to be used may be identified in the call setup request that was received from the extension telephony device. 
     In step S 1306 , the requested communication is established. During the establishment of the communication, caller ID information that includes the determined calling party identifier is sent to the called party. The call could be established for the extension telephony device using any of the many methods described above. 
       FIG. 14  illustrates steps of a method  1400  that would be performed by a software application on an extension telephony device to setup an outgoing telephony communication through the IP telephony system  120 . The method begins and proceeds to step S 1402  where the software application receives a request from a user to setup an outgoing telephony communication. In step S 1404 , the software application queries the user about which calling party identifier to use. In step S 1406 , the software application receives input from the user that indicates which calling party identifier to use. In step S 1408 , the software application sends a communication setup request to the extension connection unit  202  of an extension operations unit  200  of an IP telephony system  120 . The communication setup request includes an indication of which calling party identifier to use in caller ID information that is to be sent to the called party. In step S 1410 , the software application interacts with the extension connection unit  202  to establish the requested telephony communication. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.