Method and system of transferring a message in a session initiation protocol based communications network

1. A network node for registering in an Internet Protocol Multimedia Subsystem (IMS) communications network, the network node comprising:

a controller circuit configured to:

determine a first group identifier associated with a plurality of Proxy Call Session Control Function (P-CSCF) entities;

select, based on the first group identifier, a network address corresponding to one of the plurality of P-CSCF entities;

send, to the selected P-CSCF entity using the network address, a message to register with each of the plurality of P-CSCF entities associated with the first group identifier; and

establish a session initiation protocol (SIP) session through a different one of the plurality of P-CSCF entities associated with the first group identifier.

2. The network node of claim 1 , wherein said selecting includes the controller circuit being further configured to select the network address corresponding to the one of the plurality of P-CSCF entities for use throughout the SIP session.

3. The network node of claim 1 , wherein said selecting includes the controller circuit being further configured to select the network address corresponding to the one of the plurality of P-CSCF entities per transaction within the SIP session.

4. The network node of claim 1 , wherein said sending includes the controller circuit being further configured to send the message with the first group identifier.

5. The network node of claim 4 , wherein the controller circuit is further configured to:

select, based on a second group identifier, a network address corresponding to one of the plurality of Serving Call Session Control Function (S-CSCF) entities; and

receive, from the selected S-CSCF entity, a response to the message with the first group identifier.

6. The network node of claim 1 , wherein said selecting includes the controller circuit being further configured to perform a Domain Name Server (DNS) query using the first group identifier.

7. The network node of claim 6 , wherein the controller circuit is further configured to:

receive a list of network addresses associated with the first group identifier responsive to the DNS query.

8. The network node of claim 1 , wherein the network node is a User Agent (UA).

9. A network node for registering in an Internet Protocol Multimedia Subsystem (IMS) communications network, the network node comprising:

a controller circuit configured to:

discover a second group identifier associated with a plurality of Serving Call Session Control Function (S-CSCF) entities;

select, based on the second group identifier, a network address corresponding to one of the plurality of S-CSCF entities;

send, to the selected S-CSCF entity using the network address, a message to register with each of the plurality of S-CSCF entities associated with the second group identifier; and

establish a session initiation protocol (SIP) session through a different one of the plurality of S-CSCF entities associated with the second group identifier.

10. The network node of claim 9 , wherein said selecting includes the controller circuit being further configured to select the network address corresponding to the one of the plurality of S-CSCF entities for use throughout the SIP session.

11. The network node of claim 9 , wherein said selecting includes the controller circuit being further configured to select the network address corresponding to the one of the plurality of S-CSCF entities per transaction within the SIP session.

12. The network node of claim 9 , wherein said sending includes the controller circuit being further configured to send the message with the second group identifier.

13. The network node of claim 12 , wherein the controller circuit is further configured to:

select, based on a first group identifier, a network address corresponding to one of a plurality of Proxy Call Session Control Function (P-CSCF) entities; and

receive, from the selected S-CSCF entity via the selected P-CSCF entity, a response to the message with the second group identifier.

14. The network node of claim 9 , wherein said selecting includes the controller circuit being further configured to perform a Domain Name Server (DNS) query using the second group identifier.

15. The network node of claim 14 , wherein the controller circuit is further configured to:

receive a list of network addresses associated with the second group identifier responsive to the DNS query.

16. A first network node in a Session Initiation Protocol (SIP)-based communications network, comprising:

a repository; and

a controller circuit operationally coupled to the repository and configured to:

store, in the repository, a group identifier associated with a plurality of intermediate nodes; and

within a single session or within a single transaction of a session:

derive, based on the group identifier, a network address corresponding to a first intermediate node of the plurality of intermediate nodes;

send, to a third node via the first intermediate node, a first message, wherein the plurality of intermediate nodes are configured to synchronize data related to at least one of the first network node and the third node;

derive, based on the group identifier, a network address corresponding to a second intermediate node of the plurality of intermediate nodes; and

send the second message to the third node via the second intermediate node.

17. The first network node of claim 16 , wherein each of the plurality of intermediate nodes is a user-to-network proxy entity, a registrar, or a service node.

18. The first network node of claim 16 , wherein said deriving includes the controller circuit being further configured to perform a Domain Name Server (DNS) query based on the group identifier.

19. The first network node of claim 18 , wherein the controller circuit is further configured to:

receive a list of network addresses associated with the group identifier responsive to the DNS query.

20. The first network node of claim 16 , wherein said sending the first message includes the controller circuit being further configured to send the first message with the first group identifier; and

wherein said sending the second message includes the controller circuit being further configured to send the second message with the second group identifier.