Synchronizing call feature data between an IMS network and a legacy network

1. A communication network, comprising:

a legacy subscriber server of a legacy network that is adapted to identify feature data for a legacy call feature being provided to a dual mode device when the dual mode device receives communication access through the legacy network;

an application server of an IP Multimedia Subsystem (IMS) network that is adapted to provide an IMS call feature to the dual mode device when the dual mode device receives communication access through the IMS network; and

an IMS subscriber server adapted to store feature data for the IMS call feature being provided to the dual mode device by the IMS network;

the application server is adapted to receive a change to the feature data for the IMS call feature from the user of the dual mode device, and to notify the IMS subscriber server of the change to the feature data for the IMS call feature; and

the IMS subscriber server is further adapted to update the feature data for the legacy call feature in the legacy subscriber server based on the change to the feature data for the IMS call feature to synchronize the feature data for the legacy call feature with the feature data for the IMS call feature.

2. The communication network of claim 1 wherein:

the application server is further adapted to format a transparent data block defined for a Diameter Sh interface indicating the change to the feature data for the IMS call feature, and to transmit the transparent data block to the IMS subscriber server; and

the IMS subscriber server is further adapted to interpret the transparent data block to identify the change to the feature data for the IMS call feature, to validate the change to the feature data based on rules for the legacy subscriber server, and to update the feature data for the legacy call feature based on the feature data for the IMS call feature provided in the transparent data block.

3. The communication network of claim 2 wherein the transparent data block indicates a change to feature data for a single IMS call feature.

4. The communication network of claim 1 wherein:

the legacy subscriber server is further adapted to receive a change to the feature data for the legacy call feature being provided to the dual mode device by the legacy network; and

the IMS subscriber server is further adapted to identify the change to the feature data for the legacy call feature in the legacy subscriber server, and to notify the application server of the change to the feature data for the legacy call feature to synchronize the feature data for the IMS call feature with the feature data for the legacy call feature.

5. The communication network of claim 4 wherein:

the application server is further adapted to transmit a subscription request to the IMS subscriber server requesting to be notified of a change to the feature data.

6. The communication network of claim 4 wherein, responsive to identifying the change to the feature data, the IMS subscriber server is further adapted to format a transparent data block defined for a Diameter Sh interface indicating the change to the feature data, and to transmit the transparent data block to the application server.

7. The communication network of claim 6 wherein:

the application server is further adapted to process the transparent data block to identify the change to the feature data for the legacy call feature, and to update the feature data for the IMS call feature based on the feature data for the legacy call feature.

8. The communication network of claim 1 wherein the legacy subscriber server and the IMS subscriber server comprise a combined Home Location Register (HLR)/Home Subscriber Server (HSS).

9. A method of operating a communication network, wherein the communication network includes an IP Multimedia Subsystem (IMS) network adapted to provide IMS call features to a dual mode device and includes a legacy network adapted to provide legacy call features to the dual mode device, the method comprising:

receiving a change to feature data for an IMS call feature in an application server of the IMS network from a user of the dual mode device;

notifying an IMS subscriber server in the IMS network of the change to the feature data for the IMS call feature through the application server; and

updating, through the IMS subscriber server, feature data for a legacy call feature in a legacy subscriber server of the legacy network based on the change to the feature data for the IMS call feature to synchronize feature data for a legacy call feature with the feature data for the IMS call feature.

10. The method of claim 9 wherein notifying the IMS subscriber server comprises:

formatting a transparent data block defined for a Diameter Sh interface indicating the change to the feature data for the IMS call feature in the application server; and

transmitting the transparent data block from the application server to the IMS subscriber server.

11. The method of claim 10 wherein updating feature data for a legacy call feature comprises:

interpreting the transparent data block to identify the change to the feature data for the IMS call feature in the IMS subscriber server;

validating the change to the feature data based on rules for the legacy subscriber server; and

updating the feature data for the legacy call feature based on the change to the feature data for the IMS call feature provided in the transparent data block.

12. The method of claim 11 wherein the transparent data block indicates a change to feature data for a single IMS call feature.

13. The method of claim 9 further comprising:

receiving a change to feature data for a legacy call feature in the legacy subscriber server from the user of the dual mode device;

identifying the change to the feature data for the legacy call feature in the legacy subscriber server through the IMS subscriber server; and

notifying the application server of the change to the feature data for the legacy call feature to synchronize the feature data for the IMS call feature with the feature data for the legacy call feature.

14. The method of claim 13 wherein notifying the application server further comprises:

transmitting a subscription request from the application server to the IMS subscriber server requesting to be notified of a change to the feature data.

15. The method of claim 14 wherein notifying the application server further comprises:

formatting a transparent data block defined for a Diameter Sh interface indicating the change to the feature data; and

transmitting the transparent data block from the IMS subscriber server to the application server.

16. The method of claim 15 further comprising:

processing the transparent data block in the application server to identify the change to the feature data; and

updating the feature data for the IMS call feature based on the change to the feature data for the legacy call feature provided in the transparent data block.

17. A communication network, comprising:

a legacy subscriber server of a legacy network that is adapted to identify feature data for a legacy call feature being provided to a dual mode device when the dual mode device receives communication access through the legacy network;

an application server of an IP Multimedia Subsystem (IMS) network that is adapted to provide an IMS call feature to the dual mode device when the dual mode device receives communication access through the IMS network; and

an IMS subscriber server;

the legacy subscriber server is adapted to alert the IMS subscriber server of a change to the feature data for the legacy call feature being provided to the dual mode device by the legacy network; and

the IMS subscriber server is adapted to identify the change to the feature data for the legacy call feature in the legacy subscriber server, and to notify the application server of the change to the feature data for the legacy call feature to synchronize the feature data for the IMS call feature with the feature data for the legacy call feature.

18. The communication network of claim 17 wherein:

the application server is further adapted to transmit a subscription request to the IMS subscriber server requesting to be notified of a change to the feature data;

the IMS subscriber server is further adapted to format a transparent data block defined for a Diameter Sh interface indicating the change to the feature data, and to transmit the transparent data block to the application server; and

the application server is further adapted to process the transparent data block to identify the change to the feature data for the legacy call feature, and to update the feature data for the IMS call feature based on the feature data for the legacy call feature.

19. The communication network of claim 17 wherein:

the application server is further adapted to receive a change to the feature data for the IMS call feature, and to notify the IMS subscriber server of the change to the feature data for the IMS call feature; and

the IMS subscriber server is further adapted to update the feature data for the legacy call feature in the legacy subscriber server based on the change to the feature data for the IMS call feature to synchronize the feature data for the legacy call feature with the feature data for the IMS call feature.

20. The communication network of claim 19 wherein:

the application server is further adapted to format a transparent data block defined for a Diameter Sh interface indicating the change to the feature data for the IMS call feature, and to transmit the transparent data block to the IMS subscriber server; and

the IMS subscriber server is further adapted to interpret the transparent data block to identify the change to the feature data for the IMS call feature, and to update the feature data for the legacy call feature in the legacy subscriber server based on the feature data for the IMS call feature provided in the transparent data block.