Patent ID: 8095685

Claim:
A domain name server for connection to a mobile telecommunications network for operating as a domain name server of a home network of a subscriber of the mobile telecommunications network in a management domain, the domain name server comprising: storage means for storing, in the domain name server, names of network elements constituting the management domain of the domain name server and IP addresses corresponding to the names; reception means for receiving a request including an access point name in the management domain of the domain name server; mapping means for mapping the received access point name to a stored IP address of the network element; the domain name server of the home network further comprising identification means for identifying a received request to include the access point name that belongs to its own management domain and to be related to a defined service; and the mapping means of the domain name server of the home network being arranged to use the storage means to map, in response to identification by the identification means, the access point name to an IP address of a management domain of another domain name server that comprises an access point to a sub-system of the defined service; wherein the IP address is the IP address of a gateway General Packet Radio Service (GPRS) support node of a network related to the another management domain.