| 摘要 |
<p>A method of transporting signalling connectivity status information in an IP Multimedia Subsystem is provided. The signalling connectivity status information relates to the state of the signalling connection between a terminal and P-CSCF. When it is detected at the P-CSCF that the signalling connectivity status has changed to a new status (for example, the signalling connection between the P-CSCF and terminal has been lost) a SIP request is sent from the P-CSCF to a the S-CSCF indicating the new status. The SIP request may be a REGISTER request. Alternatively, the registration event package of the terminal is extended to include the connectivity status. The change in connectivity can then be sent in a PUBLISH request. In a further alternative, a new SIP event package is maintained by the P-CSCF. The S-CSCF subscribes to this event package and is notified by the P-CSCF upon a change of connectivity status.</p> |
