# US 12,114,249 B2 · Method for identification of traffic suitable for edge breakout and for traffic steering in a mobile network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,249 B2 - Document ID: US12114249B2 - Status: Granted - Kind: B2 - Application number: 17/782,421 - Filed: 2020-10-05 - Published: 2023-11-02 - Granted: 2024-10-08 - Earliest claimed: 2019-10-04 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Wenliang Xu; Maria Luisa Mas Rosique; Attila Mihály; Jan Backman - Web page: https://patentgrep.com/patent/US12114249B2 ## CPC - H04W 40/20: based on geographic position or location - H04L 45/04: {Interdomain routing, e.g. hierarchical routing} - H04L 61/4511: using domain name system [DNS] - H04W 28/0268: {using specific QoS parameters for wireless networks, e.g. QoS class identifier [QCI] or guaranteed bit rate [GBR] (negotiating SLA or negotiating QoS H04W28/24)} - H04W 40/246: {Connectivity information discovery} - 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 The disclosure relates to a method executed in a domain name system (DNS) proxy, and to a DNS proxy, apparatus or system for application server (AS) discovery for edge computing in a mobile network. The method comprises receiving a DNS query from a user equipment (UE) with an application fully qualified domain name (FQDN). Based on FQDN, retrieving a location of the UE that sent the DNS query; adding subnet(s) or full IP address(es) of one or more preferred location for accessing to a data network (DN) as one or more Extension mechanisms for DNS (EDNS) client subnet (ECS) options in the DNS query; forwarding the DNS query to a mobile network operator (MNO) DNS; receiving a DNS response and based on the DNS response determining an AS site and AS IP address(es); requesting traffic steering and sending the DNS response to the UE. ## Claims ### Claim 1 A method executed in a domain name system (DNS) proxy for application server (AS) discovery and traffic steering for edge computing in a mobile network, comprising: receiving a DNS query from a user equipment (UE) with an application fully qualified domain name (FQDN); upon determining that there is a service level agreement (SLA) in place for an application corresponding to the FQDN, obtaining a location of the UE that sent the DNS query from a control plane; adding at least one subnet or full IP address of one or more preferred location for accessing to a data network (DN) as one or more Extension mechanisms for DNS (EDNS) client subnet (ECS) options in the DNS query; forwarding the DNS query to a mobile network operator (MNO) DNS; receiving a DNS response comprising an ECS option, the ECS option being tailored to a corresponding ECS option of the one or more ECS option in the DNS query; triggering actions to set up traffic steering according to the ECS option received in the DNS response; and removing the ECS option from the DNS response and sending the DNS response to the UE. ### Claim 2 (depends on 1) The method of claim 1, further comprising: deploying a translation table in the DNS Proxy; obtaining the one or more preferred location for accessing to the DN for the application using the translation table and obtaining the at least one subnet or full IP address using the translation table or from a predefined configuration; and determining a DN access identifier (DNAI) that corresponds to the received ECS option, and determining at least one AS site and at least one IP address range based on an AS address included in the DNS response. ### Claim 3 (depends on 2) The method of claim 2, wherein the translation table is an SLA based translation table that maps a given user location and the application into the one or more preferred location for accessing to the DN. ### Claim 4 (depends on 2) The method of claim 2, wherein obtaining includes looking for the application FQDN received in the DNS Query in the translation table. ### Claim 5 (depends on 1) The method of claim 1, wherein, when there is an SLA in place, a user location is retrieved from the control plane by using exposure Application Programming Interfaces (APIs). ### Claim 6 (depends on 1) The method of claim 1, wherein when forwarding the DNS query to the MNO DNS, the DNS request received from the UE is temporarily buffered to be forwarded again in case of failure. ### Claim 7 (depends on 1) The method of claim 1, wherein the ECS option in the DNS response includes FAMILY, SOURCE PREFIX-LENGTH, and ADDRESS fields, which are copies from the ECS option in the DNS query; and wherein if a SCOPE PREFIX LENGTH is set to 0, no caching is done. ### Claim 8 (depends on 1) The method of claim 1, further comprising starting a timer after initiation of traffic steering; waiting for notification, for a session management function (SMF), of changes of user plane for a given session; and if no notification is received before expiry of the timer, considering that a Dynamic Uplink Classifier (UL CL) insertion and configuration failed, sending a new request with ECS(s) and executing again the method, starting at the step of forwarding the DNS query to the MNO DNS. ### Claim 9 (depends on 1) The method of claim 1, wherein the DNS proxy is deployed as a standalone entity, is deployed in one of a User Plane Function (UPF) and the MNO DNS. ### Claim 10 A method executed in a domain name system (DNS) proxy for identification of traffic suitable for edge breakout and for traffic steering in a mobile network, comprising: receiving a DNS query from a user equipment (UE) with an application fully qualified domain name (FQDN); upon determining that edge computing is applicable to the DNS query, adding one or more internet protocol (IP) address, IP address range or IP subnet as one or more Extension mechanisms for DNS (EDNS) client subnet (ECS) option to the DNS query, corresponding to one or more preferred location for accessing to a data network (DN); forwarding the DNS query; receiving a DNS response; upon determining that the received DNS response includes an ECS option that corresponds to one of the one or more ECS option of the DNS query, to which the DNS response has been tailored, triggering actions to set up traffic steering according to the ECS option; and upon successful completion of the actions triggered to set up the traffic steering, removing the ECS option from the DNS response and sending the DNS response to the UE. ### Claim 11 (depends on 10) The method of claim 10, further comprising, upon unsuccessful completion or failure of the actions triggered to set up the traffic steering, forwarding the DNS query again and excluding the ECS option that has generated the unsuccessful completion or failure. ### Claim 12 (depends on 10) The method of claim 10, further comprising, upon unsuccessful completion or failure of the actions triggered to set up the traffic steering, forwarding the DNS query again without ECS options. ### Claim 13 (depends on 10) The method of claim 10, wherein determining that edge computing is applicable to the DNS query further comprises determining whether a DNS query FQDN is under service level agreement (SLA). ### Claim 14 (depends on 13) The method of claim 13, wherein determining whether the DNS query FQDN is under SLA comprises determining whether the DNS query FQDN is included in an SLA based translation table. ### Claim 15 (depends on 14) The method of claim 14, wherein the one or more preferred location for accessing to the DN are extracted from the SLA Based Translation table, and further comprising using as inputs for reading the SLA Based Translation table at least the DNS query FQDN and a user location. ### Claim 16 (depends on 15) The method of claim 15, further comprising getting the user location from a policy control function (PCF) through existing exposure Application Programming Interfaces (APIs). ### Claim 17 (depends on 15) The method of claim 15, wherein the one or more IP address, IP address range or IP subnet to include in the ECS of the DNS query correspond to the one or more preferred location for accessing to the DN. ### Claim 18 (depends on 10) The method of claim 10, wherein forwarding the DNS query comprises forwarding the DNS query to a next DNS in a DNS hierarchy, or to a dedicated forwarder. ### Claim 19 (depends on 10) The method of claim 10, further comprising determining a DN access identifier (DNAI) that corresponds to the ECS option in the DNS response. ### Claim 20 (depends on 10) The method of claim 10, further comprising determining application server (AS) IP addresses ranges based on an AS address included in the DNS response. ### Claim 21 (depends on 20) The method of claim 20 further comprising requesting set up of traffic steering from a policy control function (PCF) by sending a request including the DNAI and the AS IP addresses ranges. ### Claim 22 (depends on 10) The method of claim 10, wherein the actions include any one or more of: sending a request for content provider (CP) policies for steering certain traffic for a local access to the DN using 3GPP Policy Authorization Service; initiating traffic steering using the CP policies; starting a timer after initiating the traffic steering; waiting for a notification from a session management function (SMF) concerning changes of a user plane for a given session; and upon expiry of the timer, if no notification is received from the SMF, or if an indication of error is received from the SMF, sending a new request with one or more ECS and executing again the method starting at the step of forwarding the DNS query. ### Claim 23 (depends on 10) The method of claim 10, wherein a service level agreement (SLA) based translation table is deployed in the DNS proxy and comprises: operator locations for accessing to the DN, at least one SLA agreement including applications FQDNs, and AS deployments and application server (AS) IP ranges at each AS site. ### Claim 24 (depends on 10) The method of claim 10, wherein forwarding the DNS query comprises forwarding the DNS query to a mobile network operator (MNO) DNS, the DNS request received from the UE being temporarily buffered to be forwarded again in case of failure. ### Claim 25 (depends on 10) The method of claim 10, wherein the ECS option in the DNS response includes FAMILY, SOURCE PREFIX-LENGTH, and ADDRESS fields, which are copies from the ECS option in the DNS query; and wherein if a SCOPE PREFIX LENGTH is set to 0, no caching is done. ### Claim 26 A domain name system (DNS) proxy for application server (AS) discovery for edge computing in a mobile network operative, the DNS proxy comprising processing circuitry configured to: receive a DNS query from a user equipment (UE) with an application fully qualified domain name (FQDN); upon determining that there is a service level agreement (SLA) in place for an application corresponding to the FQDN, obtain a location of the UE that sent the DNS query from a control plane; add at least one subnet or full IP address of one or more preferred location for accessing to a data network (DN) as one or more Extension mechanisms for DNS (EDNS) client subnet (ECS) options in the DNS query; forward the DNS query to a mobile network operator (MNO) DNS; receive a DNS response comprising an ECS option, the ECS option being tailored to a corresponding ECS option of the one or more ECS option in the DNS query; trigger actions to set up traffic steering according to the ECS option received in the DNS response; and remove the ECS option from the DNS response and sending the DNS response to the UE. ### Claim 27 A domain name system (DNS) proxy for identification of traffic suitable for edge breakout and for traffic steering in a mobile network the DNS proxy comprising processing circuitry configured to: receive a DNS query from a user equipment (UE) with an application fully qualified domain name (FQDN); upon determining that edge computing is applicable to the DNS query, add one or more internet protocol (IP) address, IP address range or IP subnet as one or more Extension mechanisms for DNS (EDNS) client subnet (ECS) option to the DNS query, corresponding to one or more preferred location for accessing to a data network (DN); forward the DNS query; receive a DNS response; upon determining that the received DNS response includes an ECS option that corresponds to one of the one or more ECS option of the DNS query, to which the DNS response has been tailored, trigger actions to set up traffic steering according to the ECS option; and upon successful completion of the actions triggered to set up the traffic steering, remove the ECS option from the DNS response and sending the DNS response to the UE.