# US 2014/0153559 A1 · Method and apparatus for selecting a gateway node > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153559 A1 - Document ID: US20140153559A1 - Status: Published application - Kind: A1 - Application number: 14/123,747 - Filed: 2012-06-01 - Published: 2014-06-05 - Earliest claimed: 2011-06-07 - Assignees: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Dinand Roeland - Web page: https://patentgrep.com/patent/US20140153559A1 ## CPC - H04W 60/00: Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration - H04L 61/4511: using domain name system [DNS] - H04L 2101/33: containing protocol addresses or telephone numbers - H04L 2101/35: containing special prefixes - H04L 2101/375: Access point names [APN] - H04W 8/06: Registration at serving network Location Register, VLR or user mobility server - H04W 48/17: {Selecting a data network PoA [Point of Attachment]} - H04W 88/16: Gateway arrangements - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for selecting a gateway node for a terminal which connects to its registered domain via an access domain and, in a predetermined scenario, an intermediate domain, the access domain having an associated domain name system arranged to return an address of a gateway node based on a domain name system query. The method includes using a first part of such a query to identify the registered domain of the terminal to the domain name system and a second part of the query to indicate to the domain name system that it should use a predetermined mapping to return the address of a gateway node based on the query, the predetermined mapping being one which returns an address of a gateway node either in the registered domain or in an intermediate domain based on the registered domain identified in the query and on the access domain. ## Claims ### Claim 1 A method of selecting a gateway node for a terminal which connects to its registered domain via an access domain and, in a predetermined scenario, an intermediate domain, the access domain having an associated domain name system which is arranged to return an address of a gateway node based on a domain name system query sent to it, and the method comprising using a first part of such a domain name system query to identify the registered domain of the terminal to the domain name system and a second part of the domain name system query to indicate to the domain name system that it should use a predetermined mapping to return an address of a gateway node based on the domain name system query, the predetermined mapping being one which returns an address of a gateway node either in the registered domain or in an intermediate domain based on the registered domain identified in the domain name system query and on the access domain. ### Claim 2 (depends on 1) The method of claim 1, wherein the predetermined mapping is arranged to specify a gateway node for each of a plurality of combinations of access domain and registered domain. ### Claim 3 (depends on 2) The method of claim 2, wherein the gateway node specified in the predetermined mapping for a particular combination of access domain and registered domain depends on proximity of the gateway node to one or both of the access domain and registered domain of the combination. ### Claim 4 (depends on 2) The method of claim 2, wherein the gateway node specified in the predetermined mapping for a particular combination of access domain and registered domain depends on routing cost between the gateway node and one or both of the access domain and registered domain of the combination. ### Claim 5 (depends on 1) The method of claim 1, wherein the gateway node specified in the predetermined mapping for a particular combination of access domain and registered domain depends on an existence of operating agreements between two or more of the access domain, the registered domain, and the intermediate domain in which the gateway node is located. ### Claim 6 (depends on 1) The method of claim 1, wherein the gateway node specified in the predetermined mapping for a particular combination of access domain and registered domain depends on whether the access domain is associated with the registered domain. ### Claim 7 (depends on 1) The method of claim 1, wherein the predetermined mapping is one which, when the domain name system is associated with an access domain that is not itself associated with the identified registered domain, returns an address of a gateway node in an intermediate domain which has an operating agreement with both the access domain and the identified registered domain, and which, when the domain name system is associated with an access domain that is itself associated with the registered domain, returns an address of a gateway node in the registered domain. ### Claim 8 (depends on 7) The method of claim 7, wherein the access domain is associated with an identified registered home domain if it is in or forms part of the identified registered home domain, and/or wherein the domain name system is associated with the access domain if it is in or forms part of the access domain or is used by the access domain. ### Claim 9 (depends on 1) The method of claim 1, wherein the predetermined mapping is a lookup table or database. ### Claim 10 (depends on 9) The method of claim 9, wherein the predetermined mapping is integrated into a remainder of the lookup table or database of the domain name system. ### Claim 11 (depends on 1) The method of claim 1, wherein the registered domain is a home domain. ### Claim 12 (depends on 1) The method of claim 1, wherein the predetermined scenario is a roaming scenario. ### Claim 13 (depends on 1) The method of claim 1, wherein the intermediate domain is a visited domain. ### Claim 14 (depends on 1) The method of claim 1, wherein the first part of the domain name system query comprises more than one element, which elements may be non-adjacent. ### Claim 15 (depends on 1) The method of claim 1, wherein the domain name system query comprises a third part identifying a type of the gateway node. ### Claim 16 (depends on 1) The method of claim 1, wherein the gateway node is a Packet Data Network (PDN), Gateway (PGW) node, or an evolved Packet Data Gateway (ePDG) node. ### Claim 17 (depends on 8) The method of claim 8, wherein the registered home domain comprises a Home Public Land Mobile Network (HPLMN), and/or wherein the intermediate domain comprises a Visited Public Land Mobile Network (VPLMN), and/or wherein the domain name system query comprises a Fully Qualified Domain Name (FQDN). ### Claim 18 (depends on 1) The method of claim 1, being performed at the terminal. ### Claim 19 (depends on 18) The method of claim 18, wherein using the first and second parts of the domain name system query comprises: constructing the domain name system query; sending the domain name system query to the domain name system; and receiving the address from the domain name system. ### Claim 20 (depends on 1) The method of claim 1, being performed at a domain name system (DNS). ### Claim 21 (depends on 20) The method of claim 20, wherein using the first and second parts of the domain name system query comprises: receiving the domain name system query from the terminal; looking up the address of a gateway node based on the received domain name system query; and sending the address to the terminal. ### Claim 22 An apparatus for selecting a gateway node for a terminal which connects to its registered domain via an access domain and, in a predetermined scenario, an intermediate domain, the access domain having an associated domain name system which is arranged to return an address of a gateway node based on a domain name system query sent to it, and the apparatus comprising at least one component arranged to use a first part of such a domain name system query to identify the registered domain of the terminal to the domain name system and a second part of the domain name system query to indicate to the domain name system that it should use a predetermined mapping to return the address of a gateway node based on the domain name system query, the predetermined mapping being one which returns an address of a gateway node either in the registered domain V or in an intermediate domain based on the registered domain identified in the domain name system query and on the access domain. ### Claim 23 (depends on 22) The apparatus of claim 22, wherein the apparatus comprises a domain name system (DNS). ### Claim 24 (depends on 23) The apparatus of claim 23, wherein the at least one component comprises: a receiver arranged to receive the domain name system query from the terminal; a processor arranged to look up the address of a gateway node based on the received domain name system query; and a transmitter arranged to send the address to the terminal. ### Claim 25 (depends on 22) The apparatus of claim 22, wherein the apparatus comprises a terminal. ### Claim 26 (depends on 25) The apparatus of claim 25, wherein the at least one component comprises: a processor arranged to construct the domain name system query; a transmitter arranged to send the domain name system query to the domain name system; and a receiver arranged to receive the address from the domain name system. ### Claim 27 A non-transitory computer-readable medium having computer instructions stored therein, which when executed by a processor, cause the processor to perform operations comprising: selecting a gateway node for a terminal which connects to its registered domain via an access domain and, in a predetermined scenario, an intermediate domain, the access domain having an associated domain name system which is arranged to return an address of a gateway node based on a domain name system query sent to it; and using a first part of such a domain name system query to identify the registered domain of the terminal to the domain name system and a second part of the domain name system query to indicate to the domain name system that it should use a predetermined mapping to return an address of a gateway node based on the domain name system query, the predetermined mapping being one which returns an address of a gateway node either in the register domain or in an intermediate domain based on the registered domain identified in the domain name system query and on the access domain.