Monitoring connection state to a user terminal in a telecommunications system

The invention claims a are used to display in a telecommunications system and a telecommunications system is user terminal connection method, a telecommunications system comprises an user terminal (UE) is unit (CSCF), and a user data the part of transmission (SGSN, GGSN); the component system with the control unit is separately, knows of the user terminal (UE) is state's system unit is provided with a interface for transmitting message to the control unit, wherein the information indicating connected with, wherein the control unit (CSCF) is provided with a based on receiving feedback message to determine the user terminal (UE) connected with the.