Method and system for implementing a stateless back to back user agent

• US 20080080525A1
• Filed: 09/29/2006
• Published: 04/03/2008
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Unify Patente GmbH & Co. KG (Atos Se)
• Original Assignee: Siemens Enterprise Communications, Inc. (Atos SE)
• Inventors: Virk, Jagjiwan, Blohm, Jeffrey, Chatilov, Alexandre, Zhu, Ting
• Granted Patent: US 7,756,115 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 65/1045 Proxies, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]

Abstract

A method for providing a stateless Session Interface Protocol (SIP) back to back user agent (B2BUA) comprising receiving a SIP message and determining if the SIP message is a SIP request. The SIP request further comprises a request to create an original SIP dialog or a request for an existing SIP dialog. Method further comprises determining if the SIP message is a SIP response. The SIP response may further comprise a provisional SIP response or a final SIP response. Method is suitable for transforming the SIP request, transforming the SIP response, transmitting the transformed SIP request to a new destination, and transmitting the transformed SIP response to a request originator.

Claims

1. A method for providing a stateless Session Interface Protocol (SIP) back to back user agent (B2BUA) comprising:

receiving a SIP message;

determining if said SIP message is a SIP request;

determining if said SIP message is a SIP response;

transforming said SIP request;

transforming said SIP response;

transmitting said transformed SIP request to a new destination; and

transmitting said transformed SIP response to a request originator.

2. The method of claim 1, further comprising inserting a first record-route header into a user agent server.

3. The method of claim 1, further comprising inserting said first record-route header into a user agent client.

4. The method of claim 3, further comprising inserting a first via header into a user agent server.

5. The method of claim 4, further comprising inserting said first via header into a user agent client.

6. The method of claim 5, wherein said first record-route header and said first via header are suitable for transferring SIP dialog state data to an endpoint.

7. The method of claim 6, wherein said first record-route header and said first via header are suitable for reconstructing said SIP dialog state data on a receiving second record-route header or a second via header in a subsequent SIP message received from said endpoint.

9. The method of claim 7, further comprising inserting a first record-route header into a user agent server.

10. The method of claim 9, further comprising inserting said first record-route header into a user agent client.

11. The method of claim 10, further comprising inserting a first via header into a user agent server.

12. The method of claim 11, further comprising inserting said first via header into a user agent client.

13. The method of claim 12, wherein said first record-route header and said first via header are suitable for transferring SIP dialog state data to an endpoint.

14. The method of claim 13, wherein said first record-route header and said first via header are suitable for reconstructing said SIP dialog state data on a receiving second record-route header or a second via header in a subsequent SIP message received from said endpoint.

8. A method for providing a stateless Session Interface Protocol (SIP) back to back user agent (B2BUA) comprising:

receiving a SIP message;

determining if said SIP message is a SIP request, said SIP request further comprising a request to create an original SIP dialog or a request for an existing SIP dialog;

determining if said SIP message is a SIP response, said SIP response further comprising a provisional SIP response or a final SIP response;

transforming said SIP request;

transforming said SIP response;

transmitting said transformed SIP request to a new destination; and

transmitting said transformed SIP response to a request originator.

15. A system comprising:

a back-to-back user agent, said back-to-back user agent further comprising;

a user agent server; and

a user agent client, said user agent client concatenated with said user agent server to form said back-to-back user agent,

wherein said back-to-back user agent is suitable for inserting a record-route header and a via header in both said user agent server and said user agent client, said record-route header and said via header suitable for transferring SIP dialog state data to an endpoint and reconstructing said SIP dialog state data on a receiving record-route header and a receiving via header in a subsequent SIP message received from said endpoint.

16. The system of claim 15, wherein said user agent server receives a request having an original source and destination header.

17. The system of claim 16, wherein said back-to-back user agent is suitable for performing a transformation on said request.

18. The system of claim 17, wherein said transformation is a From header and a To header modification.

19. The system of claim 16, 0wherein said transformation is performed utilizing static rules configured for said request.

20. The system of claim 15, wherein said receiving via header is identical to said receiving record-route header and is suitable for reconstructing said request if a negative response from said endpoint is received.