METHODS AND DEVICES FOR TRANSMITTING SIGNAL CONNECTION INFORMATION RELATING TO SIGNAL CONNECTION BETWEEN TERMINAL AND PROXY CALL SESSION CONTROL FUNCTION (P-CSCF) IN INTERNET PROTOCOL MULTIMEDIA SUBSYSTEM (IMS)

摘要

FIELD: information technology.;SUBSTANCE: disclosed is a method of transmitting information on the state of a signal connection in IMS. When on P-CSCF it has been determined that the state of the signal connection has changed to a new state, for example, the signal connection between P-CSCF and the terminal has been lost, a SIP request is sent from the P-CSCF to a serving call session control of unction (S-CSCF) module indicating the new state. The SIP request can be a REGISTER request. Alternatively, the terminal registration event packet is extended in order to include the state of the connection. The change in the connection can then be sent in a PUBLISH request. In the next alternative version, a new SIP event packet is supported by P-CSCF, and the S-CSCF subscribes that event packet and notifies using the P-CSCF when the state of the connection changes.;EFFECT: indication that a communication line previously used to transmit protocol signals for initialising a session between a user and a proxy call session control function module has been lost.;20 cl, 6 dwg