Distributed call server supporting communication sessions in a communication system and method

1. An apparatus for supporting a communication session between at least two communication devices, the apparatus comprising:

a plurality of processors, each processor operable to perform at least one function in support of a communication session portion of a communication session; and

a controller operable to transfer the communication session from one of the processors associated with a first portion of the communication session to another of the processors associated with a second portion of the communication session, the controller associating a distinct network address of the one processor and a distinct network address of the other processor with the first portion and the second portion, respectively, of the communication session and informing at least one of the communication devices involved in the communication session of the distinct network address associated with each of the communication session portions.

2. The apparatus of claim 1 , wherein:

the different portions of the communication session comprise a conference call portion and a non-conference call portion;

one of the processors performs at least one function associated with the conference call portion of the communication session; and

another of the processors performs at least one function associated with the non-conference call portion of the communication session.

3. The apparatus of claim 1 , further comprising a conductor operable to receive a request associated with the communication session and to provide the request to the controller.

4. The apparatus of claim 3 , wherein the conductor, controller, and processors comprise software processes executed by the apparatus.

5. The apparatus of claim 3 , wherein:

the request comprises a Session Initiation Protocol (SIP) message; and

the conductor represents a SIP service portal.

6. The apparatus of claim 1 , further comprising a plurality of ports, each of the processors associated with a unique set of one or more ports.

7. The apparatus of claim 1 , wherein:

the controller comprises a first controller; and

the first controller is further operable to transmit first messages to a second controller and receive second messages from a third controller, the first and second messages associated with communication sessions handled by the controllers, the first messages comprising at least one of one or more messages generated by the first controller and one or more of the second messages.

8. The apparatus of claim 7 , wherein:

the first controller is operable to transmit the first messages to the second controller using a primary address associated with the second controller; and

the first controller is further operable to use a backup address when communication with the second controller fails.

9. A method for supporting a communication session between at least two communication devices, the method comprising:

establishing a communication session using one of a plurality of processors, the communication session comprising a plurality of portions, the processors operable to perform at least one function in support of different portions of the communication session;

detecting a transition from one of the portions of the communication session to another of the portions of the communication session;

transferring the communication session from one of the processors associated with one portion of the communication session to another of the processors associated with another portion of the communication session, a distinct network address associated with the one processor and a distinct network address associated with the other processor; and

informing at least one of the communication devices involved in the communication session of the distinct network address associated with each of the communication session portions.

10. The method of claim 9 , wherein:

the different portions of the communication session comprise a conference call portion and a non-conference call portion;

one of the processors is associated with the conference call portion of the communication session; and

another of the processors is associated with the non-conference call portion of the communication session.

11. The method of claim 10 , wherein detecting the transition comprises detecting an invocation of a three-way calling feature during a non-conference communication session.

12. The method of claim 9 , further comprising receiving a request associated with the communication session, the request comprising a Session Initiation Protocol (SIP) message.

13. The method of claim 9 , wherein transferring the communication session comprises transferring a communication device involved in the communication session from a first port to a second port, one of the processors associated with the first port and another of the processors associated with the second port.

14. The method of claim 9 , wherein:

the controller comprises a first controller; and

further comprising transmitting first messages from the first controller to a second controller and receiving second messages from a third controller, the first and second messages associated with communication sessions handled by the controllers, the first messages comprising at least one of one or more messages generated by the first controller and one or more of the second messages.

15. The method of claim 14 , wherein:

the first controller is operable to transmit the first messages using a primary address associated with the second controller; and

the first controller is further operable to use a backup address when communication with the second controller fails.

16. An apparatus for supporting communication sessions between at least two communication devices, the apparatus comprising:

a plurality of processors, each processor operable to perform at least one function in support of a communication session; and

a first controller operable to:

transfer the communication session from one of the processors to another of the processors during different portions of the communication session and inform at least one of the communication devices involved in the communication session of a distinct network address associated with the one processor and a distinct network address associated with the other processor with each associated with the different portions of the communication session; and

transmit first messages to a second controller and receive second messages from a third controller, the first and second messages associated with communication sessions handled by the controllers, the first messages comprising at least one of one or more messages generated by the first controller and one or more of the second messages.

17. The apparatus of claim 16 , wherein:

the first controller is operable to transmit the first messages to the second controller using a primary address associated with the second controller; and

the first controller is further operable to use a backup address when communication with the second controller fails.

18. The apparatus of claim 16 , wherein:

the different portions of the communication session comprise a conference call portion and a non-conference call portion;

one of the processors is associated with the conference call portion of the communication session; and

another of the processors is associated with the non-conference call portion of the communication session.

19. The method of claim 13 , further comprising receiving a request associated with the communication session, the request comprising a Session Initiation Protocol (SIP) message.

20. The apparatus of claim 16 , further comprising a conductor operable to receive a request associated with the communication session and to provide the request to the controller, wherein the request the request comprises a Session Initiation Protocol (SIP) message.

21. The method of claim 10 , wherein detecting the transition comprises detecting that all but two participants to a conference call have left the conference call.