System and method for SIP user agent identification and efficient binding

1. A method for use on a Session Initiation Protocol (SIP) registration server for registering user agents, comprising:

receiving a REGISTER message which includes a binding key located in a Contact header of the REGISTER message, wherein the binding key comprises a Contact Uniform Resource Identifier (URI) and identifying information for a device associated with a user agent to be registered;

determining whether a prior binding associated with the binding key exists in a registration repository;

creating a new binding associated with the binding key and adding the new binding to the registration repository when no prior binding associated with the binding key exists in the registration repository; and

refreshing the prior binding in the registration repository when the prior binding associated with the binding key exists in the registration repository.

2. The method of claim 1 , further comprising:

determining whether the REGISTER message specifies an expiration interval when the prior binding associated with the binding key exists in the registration repository;

removing the prior binding from the registration repository when the REGISTER message specifies an expiration interval of 0;

refreshing the prior binding in the registration repository when the REGISTER message does not specify an expiration interval of 0.

3. The method of claim 1 , further comprising:

validating registration parameters for the prior binding in the registration repository when the prior binding associated with the binding key exists in the registration repository.

4. The method of claim 1 , wherein the identifying information is a unique identifier.

5. The method of claim 1 , wherein the identifying information is a personal identification number (PIN).

6. The method of claim 1 , wherein the identifying information is a PIN and user name.

7. The method of claim 1 , further comprising:

adding a connection-binding mapping to the registration repository when a user agent to be registered uses a connection-orientated protocol.

8. A network component, comprising:

a processor configured to receive a REGISTER message which includes a binding key located in a Contact header of the REGISTER message, wherein the binding key comprises a Contact Uniform Resource Identifier (URI) and identifying information for a device associated with a user agent to be registered, determine whether a prior binding associated with the binding key exists in a registration repository, create a new binding associated with the binding key and adding the new binding to the registration repository when no prior binding associated with the binding key exists in the registration repository, and refresh the prior binding in the registration repository when the prior binding associated with the binding key exists in the registration repository.

9. The network component of claim 8 , wherein the processor is further configured to determine whether the REGISTER message specifies an expiration interval when the prior binding associated with the binding key exists in the registration repository, remove the prior binding from the registration repository when the REGISTER message specifies an expiration interval of 0, and refresh the prior binding in the registration repository when the REGISTER message does not specify an expiration interval of 0.

10. The network component of claim 8 , wherein the processor is further configured to validate registration parameters for the prior binding in the registration repository when the prior binding associated with the binding key exists in the registration repository.

11. The network component of claim 8 , wherein the processor is further configured to add a connection-binding mapping to the registration repository when a user agent to be registered uses a connection-orientated protocol.

12. A method for use on a user agent for registering with a Session Initiation Protocol (SIP) registration server, comprising:

sending a REGISTER message to the SIP registration server, wherein the REGISTER message includes a binding key located in a Contact header of the REGISTER message, wherein the binding key comprises a Contact Uniform Resource Identifier (URI) and identifying information for a device associated with a user agent to be registered.

13. The method of claim 12 , wherein the binding key is located in a Contact header of the REGISTER message.