Abstract: The inventive method allows integrated communications in a telecommunications network, which combines a Mobile Telecommunications Network (PLMN) and at least an other, wired packet switching or circuit switched network (PSTN/ISDN, INTERNET), with a subscriber's Mobile Station (MS) designed to operate in the Mobile Telecommunications Network (PLMN) and a second communication terminal (IP-T; IP-MS; SC-T) of the subscriber designed to operate in the other or one of the other networks PSTN/ISDN, INTERNET and with an extended Mobile Services Switching Center (MSCX) that over a gateway (IP-GW) connects to the packet switching network (INTERNET).