Application server update message processing

1. A media gateway controller in a packet communication network, the media gateway controller comprising:

an interface configured to receive a first plurality of update messages from a first plurality of application servers of a first enterprise network wherein the first plurality of update messages indicate a status of the first plurality of application servers, receive a second plurality of update messages from a second plurality of application servers of a second enterprise network wherein the second plurality of update messages indicate a status of the second plurality of application servers, and receive a third plurality of update messages from a plurality of gateways wherein the third plurality of update messages indicate a status of the gateways and wherein the interface is configured to receive a call setup request for a call wherein the call setup request indicates a calling party and a one of the first and second enterprise networks;

a processor configured to process the update messages to update a routing table based on the status of the first and second plurality of application servers and the plurality of gateways, wherein the processor is further configured to process the call setup request to select the first plurality of application servers based on the one enterprise network indicated in the call setup request and select the one application server of the first plurality of application servers based on the status of the first plurality of application servers; and

wherein the interface is further configured to transfer a query indicating the calling party to the one application server and to receive a response from the one application server indicating whether the call is allowed based on a calling plan for the calling party stored by the one application server.

2. The media gateway controller of claim 1 wherein the interface is further configured to receive a response from the one application server indicating first instructions for the call and transfer second instructions for the call.

3. The media gateway controller of claim 2 wherein the processor is further configured to process the first instructions for the call to determine second instructions for the call.

4. The media gateway controller of claim 3 wherein the first instructions indicate that the call is allowed based on a calling plan for the calling party.

5. The media gateway controller of claim 4 wherein the second instructions indicate routing instructions for the call.

6. The media gateway controller of claim 3 wherein the first instructions indicate that the call is not allowed based on a calling plan for the calling party.

7. The media gateway controller of claim 1 wherein the update messages comprise Telephony Routing over Internet Protocol (TRIP) update messages.

8. The media gateway controller of claim 1 wherein the routing table comprises a Telephony Routing over Internet Protocol (TRIP) routing table.

9. A method of operating a media gateway controller in a packet communication network, the method comprising:

in an interface, receiving a first plurality of update messages from a first plurality of application servers of a first enterprise network wherein the first plurality of update messages indicate a status of the first plurality of application servers, receiving a second plurality of update messages from a second plurality of application servers of a second enterprise network wherein the second plurality of update messages indicate a status of the second plurality of application servers, and receiving a third plurality of update messages from a plurality of gateways wherein the third plurality of update messages indicate a status of the gateways and wherein the interface is configured to receive a call setup request for a call wherein the call setup request indicates a calling party and a one of the first and second enterprise networks;

in a processor, processing the update messages to update a routing table based on the status of the first and second pluralities of application servers and the plurality of gateways, wherein the processor is further configured to process the call setup request to select the first plurality of application servers based on the one enterprise network indicated in the call setup request and select the one application server of the first plurality of application servers based on the status of the first plurality of application servers; and

wherein the interface is further configured to transfer a query indicating the calling party to the one application server and to receive a response from the one application server indicating whether the call is allowed based on a calling plan for the calling party stored by the one application server.

10. The method of claim 9 further comprising, in the interface, receiving a response from the one application server indicating first instructions for the call and transferring second instructions for the call.

11. The method of claim 10 further comprising, in the processor, processing the first instructions for the call to determine second instructions for the call.

12. The method of claim 11 wherein the first instructions indicate that the call is allowed based on a calling plan for the calling party.

13. The method of claim 12 wherein the second instructions indicate routing instructions for the call.

14. The method of claim 11 wherein the first instructions indicate that the call is not allowed based on a calling plan for the calling party.

15. The method of claim 9 wherein the update messages comprise Telephony Routing over Internet Protocol (TRIP) update messages.

16. The method of claim 9 wherein the routing table comprises a Telephony Routing over Internet Protocol (TRIP) routing table.