Method and system of transferring a message in a session initiation protocol based communications network
Systems and methods of transferring a message in a Session Initiation Protocol (SIP)-based communications network, from a first node to a third node using a second node are provided. In one exemplary embodiment, a method of registering in an Internet Protocol Multimedia Subsystem (IMS) communications network, a User Agent (UA) using a Proxy Call Session Control Function (P-CSCF) entity with a Serving Call Session Control Function (S-CSCF) entity may include determining a first group identifier associated with a plurality of P-CSCF entities. Based on the first group identifier, the method may include selecting a network address corresponding to one of the plurality of P-CSCF entities. Further, the method may include storing subscriber data in a repository associated with the selected P-CSCF entity. Also, the method may include synchronizing, by the selected P-CSCF entity, the subscriber data stored in the repository associated with the selected P-CSCF entity to the remaining P-CSCF entities of the plurality of P-CSCF entities. The UA may be ready to establish and receive SIP sessions through any of the plurality of P CSCF entities.
1. A method performed by a User Agent (UA) of registering in an Internet Protocol Multimedia Subsystem (IMS) communications network, the UA using a Proxy Call Session Control Function (P-CSCF) entity with a Serving Call Session Control Function (S-CSCF) entity, the method comprising:
determining, by the UA, a first group identifier associated with a plurality of P-CSCF entities;
selecting, by the UA and based on the first group identifier, a network address corresponding to one of the plurality of P-CSCF entities;
sending, by the UA, 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
establishing, by the UA, 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 method of claim 1 , further comprising:
using the selected P-CSCF entity throughout a SIP session.
3. The method of claim 1 , wherein selecting includes selecting the P-CSCF entity per transaction within a SIP session.
4. The method of claim 3 , further comprising:
sending, by the UA, to the selected P-CSCF entity, a message including the first group identifier.
5. The method of claim 4 , further comprising:
selecting, by the UA and based on a second group identifier, a network address corresponding to one of the plurality of S-CSCF entities; and
receiving, by the UA, from the selected S-CSCF entity a response to the message.
6. The method of claim 3 , wherein selecting the P-CSCF entity using the first group identifier includes performing a Domain Name Server (DNS) query using the first group identifier.
7. The method of claim 6 , further comprising:
receiving, by the UA, a list of network addresses associated with the first group identifier in response to the DNS query.
8. A method performed by a User Agent (UA) of registering in an Internet Protocol Multimedia Subsystem (IMS) communications network, the UA using a Proxy Call Session Control Function (P-CSCF) entity with a Serving Call Session Control Function (S-CSCF) entity, the method comprising:
discovering, by the UA, a second group identifier associated with a plurality of S-CSCF entities;
selecting, by the UA and based on the second group identifier, a network address corresponding to one of the plurality of S-CSCF entities;
sending, by the UA, 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 first group identifier; and
establishing, by the UA, a session initiation protocol (SIP) session through a different one of the plurality of S-CSCF entities associated with the first group identifier.
9. The method of claim 8 further comprising thereafter using the selected S-CSCF entity throughout a SIP session.
10. The method of claim 8 further comprising, thereafter repeating the selecting the S-CSCF entity per transaction within a SIP session.
11. The method of claim 10 further comprising thereafter including the second group identifier in the message transmitted by the UA towards the selected S-CSCF entity.
12. The method of claim 11 further comprising:
selecting, by the UA and based on a first group identifier, a network address corresponding to one of a plurality of P-CSCF entities; and
receiving, by the UA, from the selected S-CSCF entity via the selected P-CSCF entity, a response to the message.
13. The method of claim 10 , wherein selecting the S-CSCF entity on the basis of the second group identifier includes performing a Domain Name Server (DNS) query using the second group identifier.
14. The method of claim 11 , further comprising:
receiving, by the UA, a list of network addresses associated with the second group identifier in response to the DNS query.