Maintaining cached terminal data

• US 20060089966A1
• Filed: 08/25/2005
• Published: 04/27/2006
• Est. Priority Date: 10/05/2004
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Stille, Mats, Tystad, Fredrik
• Granted Patent: US 8,411,580 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/303 Terminal profiles

Abstract

A method of maintaining cached Session Initiation Protocol (SIP) terminal capability information at an end user terminal of a telecommunication system, for one or more other end user terminals. The method comprises predefining one or more signalling message properties for signalling messages to be received from peer terminals, and recording the properties at said end user terminal, examining incoming signalling messages received from peer terminals to determine whether or not they possess a predefined property, and if an incoming signalling message does possess a predefined property, reacting by refreshing the cached capability information for the sending terminal.

Claims

1. A method of maintaining cached information at an end user terminal of a telecommunication system, the cached information comprising information for one or more other end user terminals and/or associated subscribers and the cached information being used to control the establishment of communication channels between terminals, the method comprising:

predefining one or more signalling message properties for signalling messages to be received from peer terminals;

examining incoming signalling messages received from peer terminals to determine whether or not they possess a predefined property; and

if an incoming signalling message does possess a predefined property, reacting by refreshing the cached information for the sending terminal.

2. A method according to claim 1, the method comprising initially populating the cache for each other end user terminal at the first communication with that other terminal.

3. A method according to claim 1, wherein said predefined properties comprise a combination of message type and message content.

4. A method according to claim 1, wherein said cached information is capability information.

5. A method according to claim 3, wherein said cached information is capability information and said message content is content which is indicative of a change in the capabilities of the terminal and/or subscriber from whom the message is sent.

6. A method according to claim 4, wherein said step of refreshing the cached capability information for the sending terminal comprises updating the cache entry for that terminal with information contained in a received message and/or sending a capability request to the sending terminal and refreshing the cache based upon the contents of the response.

7. A method according to claim 4, wherein said predefined signalling message properties comprise one or more of the following:

a connection initiation failure message returned in response to a connection initiation request;

a connection initiation request containing or pertaining to capabilities not currently identified in the cached information; and

a message relating to capability negotiation.

8. A method according to claim 4, wherein said capability information comprises Session Initiation Protocol terminal capabilities.

9. A method according to claim 8, wherein Session Initiation Protocol capability information is exchanged between terminals using SIP OPTIONS or INVITE mechanisms.

10. A method according to claim 4, wherein said capability information comprises H.324 terminal capabilities.

11. A method according to claim 1, wherein said predefined message properties are stored at the end user terminal or are implemented by way of executable software code.

12. An end user terminal for use with a telecommunications network, the terminal comprising:

a first memory storing cached information comprising information for one or more other end user terminals and/or associated subscribers; and

processing means for examining incoming signalling messages received from peer terminals to determine whether or not they possess a predefined property, and if an incoming signalling message does possess a predefined property, for performing a refresh of the cached information for the sending terminal.

13. A terminal according to claim 12, said cached information being capability information.

14. A terminal according to claim 12, the terminal being a Session Initiation Protocol enabled terminal.

15. A terminal according to claim 12, the terminal being an H.324 enabled terminal.

16. A terminal according to claim 12 and comprising second memory storing one or more predefined signalling message properties for signalling messages to be received from peer terminals.

17. A method of maintaining cached information at an end user terminal of a telecommunication system, the cached information comprising information for one or more other end user terminals and/or associated subscribers and the cached information being used repeatedly to control the establishment of communication channels between terminals, the method comprising:

predefining one or more signalling message types for signalling messages to be received from peer terminals;

examining incoming signalling messages received from peer terminals to determine whether or not they match one of said predefined types; and

if an incoming signalling message does match one of said predefined types, reacting by refreshing the cached information for the sending terminal.