Providing session initiation protocol (SIP) call control functions to public switched telephone network (PSTN)-based call controller

1. A method comprising:

receiving, by one or more devices of a Session Initiation Protocol (SIP) network and from a SIP proxy server, a modified SIP INVITE request associated with an outbound call,

the outbound call being from a Public Switched Telephone Network (PSTN)-based user device that is associated with a calling party;

extracting, by the one or more devices of the SIP network, data associated with a SIP-based user device from the modified SIP INVITE request,

the data including a Simple Object Access Protocol (SOAP)-remote procedure call (RPC) Uniform Resource Identifier (URI);

generating, by the one or more devices of the SIP network, a RPC invocation based on the SOAP-RPC URI;

providing, by the one or more devices of the SIP network and to a PSTN-based call controller, the RPC invocation and the modified SIP INVITE request by using a RPC interface of the one or more devices of the SIP network; and

enabling, by the one or more devices of the SIP network and for the outbound call, communication, via the RPC interface, with the SIP-based user device.

2. The method of claim 1 , where the RPC invocation comprises an invocation of an “OnCallOffered” RPC method.

3. The method of claim 1 , where enabling the communication comprises:

receiving a transfer RPC invocation and a SIP INVITE request;

creating, for the outbound call, a SIP back-to-back user agent call control instance based on the transfer RPC invocation and the SIP INVITE request;

providing the SIP INVITE request to the SIP-based user device;

receiving a SIP INVITE “200” message from the SIP-based user device based on the SIP request;

providing an “OnAnswer” RPC invocation and the SIP INVITE “200” message to the PSTN-based call controller; and

establishing the communication with the SIP-based user device based on the “OnAnswer” RPC invocation and the SIP INVITE “200” message.

4. The method of claim 3 , where enabling the communication further comprises:

receiving a SIP REFER request from the SIP-based user device;

providing the SIP REFER request to the PSTN-based call controller;

providing an “OnRefer” remote procedure call (RPC) invocation, based on the SIP REFER request, to the PSTN-based call controller; and

providing another SIP INVITE request to another SIP-based user device referred to in the SIP REFER request.

5. The method of claim 1 , where the one or more devices include a SIP-based remote call controller.

6. A method comprising:

receiving, by one or more devices of a Public Switched Telephone Network (PSTN) network, an outbound call associated with a calling party;

generating, by the one or more devices of the PSTN network, a PSTN Initial Address Message (IAM) associated with the outbound call;

providing, by the one or more devices of the PSTN network, the PSTN IAM to a network device associated with a Session Initiation Protocol (SIP) network;

receiving, by the one or more devices of the PSTN network, a remote procedure call (RPC) invocation and a SIP INVITE request associated with the outbound call;

modifying, by the one or more devices of the PSTN network, the SIP INVITE request to produce a modified SIP INVITE request;

providing, by the one or more devices of the PSTN network, a transfer remote procedure call (RPC) invocation and the modified SIP INVITE request to a SIP-based remote call controller;

receiving an “OnAnswer” RPC invocation and a PSTN Answer Message (ANM) based on the transfer RPC invocation and the modified SIP INVITE request; and

establishing, for the outbound call, communication with a SIP-based device based on the “OnAnswer” RPC invocation and the PSTN ANM.

7. The method of claim 6 , where providing the PSTN IAM comprises:

providing data to the network device associated with the SIP network, the data including at least one of:

a telephone number associated with the SIP-based device; or

a Simple Object Access Protocol (SOAP-RPC Uniform Resource Identifier (URI).

8. The method of claim 7 , where the RPC invocation comprises an invocation of an “OnCallOffered” RPC method.

9. The method of claim 6 , further comprising:

receiving an “OnRefer” RPC invocation and a SIP REFER request; and

creating a new outbound call based on the SIP REFER request.

10. The method of claim 9 , further comprising:

establishing the communication of the new outbound call with another SIP-based device referred to in the SIP REFER request.

11. The method of claim 6 , where the one or more devices include a PSTN-based call controller.

12. A device comprising:

one or more processors to:

receive, from a Session Initiation Protocol (SIP) proxy server, a modified SIP INVITE request associated with an outbound call from a Public Switched Telephone Network (PSTN)-based user device that is associated with a calling party,

extract data associated with a SIP-based user device from the modified SIP INVITE request,

the data including a Simple Object Access Protocol (SOAP)-remote procedure call (RPC) Uniform Resource Identifier (URI), generate a RPC invocation based on the SOAP-RPC URI,

provide, to a PSTN-based call controller, the RPC invocation and the modified SIP INVITE request by using a RPC interface of a SIP network, and

enable, for the outbound call, communication, via the RPC interface with the SIP-based user device.

13. The device of claim 12 , where the device comprises a SIP-based remote call controller.

14. The device of claim 12 , where, when enabling the communication, the one or more processors are to:

provide SIP call control functions to the PSTN-based call controller for handling the outbound call.

15. The device of claim 12 , where the RPC invocation comprises invocation of an “OnCallOffered” RPC method.

16. The device of claim 12 , where, when enabling the communication, the one or more processors are to:

receive a transfer RPC invocation and a Session Initiation Protocol (SIP) INVITE request,

create, for the outbound call, a SIP back-to-back user agent call control instance based on the transfer RPC invocation and the SIP INVITE request,

provide the SIP INVITE request to the SIP-based user device,

receive a SIP INVITE “OK” message from the SIP-based user device based on the SIP request,

provide an “OnAnswer” RPC invocation and the SIP INVITE “OK” message to the PSTN-based call controller, and

establish, for the outbound call, the communication with the SIP-based device based on the “OnAnswer” RPC invocation and the SIP INVITE “OK” message.

17. The device of claim 16 , where, when enabling the communication, the one or more processors are further to:

receive a SIP REFER request from the SIP-based user device,

provide the SIP REFER request to the PSTN-based call controller,

provide an “OnRefer” RPC invocation, based on the SIP REFER request, to the PSTN-based call controller, and

generate another SIP INVITE request to a SIP-based device referred to in the SIP REFER request.

18. The device of claim 12 , where the device includes a SIP-based remote call controller.

19. A system comprising:

a Public Switched Telephone Network (PSTN)-based call controller to:

receive an outbound call associated with a calling party,

the outbound call being from a PSTN-based user device that is associated with the calling party,

provide the outbound call to a Session Initiation Protocol (SIP) network; and

a SIP-based remote call controller to:

receive information associated with the outbound call,

provide, to the PSTN-based call controller, a request for the outbound call by using a remote procedure call (RPC) interface of the SIP-based remote controller, and

enable, for the outbound call, communication, via the RPC interface, with a SIP-based user device that is associated with a called party,

the PTSN-based call controller being further to:

receive an “OnRefer” RPC invocation and a SIP REFER request,

create a new outbound call based on the SIP REFER request, and

establish, for the new outbound call, communication with another SIP-based user device referred to in the SIP REFER request.

20. The system of claim 19 , where the PSTN-based call controller is further to:

receive a SIP INVITE request associated with the outbound call from the SIP-based remote call controller,

modify the SIP INVITE request to produce a modified SIP INVITE request,

provide a transfer RPC invocation and the modified SIP INVITE request to the SIP-based remote call controller,

receive an “OnAnswer” RPC invocation and a PSTN Answer Message (ANM) based on the transfer RPC invocation and the modified SIP INVITE request, and

establish, for the outbound call, communication with the SIP-based device based on the “OnAnswer” RPC invocation and the PSTN ANM.

21. The system of claim 19 , where the SIP-based remote call controller is further to:

receive the SIP REFER request from the SIP-based user device,

provide the SIP REFER request to the PSTN-based call controller, and

provide the “OnRefer” RPC invocation, based on the SIP REFER request, to the PSTN-based call controller.

22. The system of claim 19 , where the PSTN-based call controller is further to:

execute an “OnCallOffered” SOAP-RPC method based on the “On Refer” RPC invocation.