DNS traffic routing for ues with the same IP address

Abstract

Disclosed herein is at least a method performed by a V-SMF) in a VPLMN for Home Routed (HR) Session Breakout (SBO) for a PDU session of a UE using a private Internet Protocol, IP, address. The method comprises: obtaining tunneling information for establishing a tunnel between a V-UPF and a V-EASDF (e.g., for HR-SBO of the PDU session of the UE using the private IP address); and performing one or more operations based on the obtained tunneling information, the one or more operations being related to establishing a tunnel between the V-UPF and the V-EASDF (e.g., for HR-SBO of the PDU session of the UE using the private IP address).

Description

TITLEDNS TRAFFIC ROUTING FOR UEs WITH THE SAME IP ADDRESSBACKGROUND

[0001] In 3rdGeneration Partnership Project (3GPP) 5thGeneration (5G) System (5GS), in the Home Routed-Session Break Out scenario, there are use cases in which the User Equipments (UEs) from the same or different Home Public Land Mobile Networks (PLMNs) establish a Home-Routed Protocol Data Unit (PDU) session with the same Private UE Internet Protocol (IP) address. If these UEs are roaming in the same Visited Public Land Mobile Network (VPLMN) that supports Home Routed-Session Break Out (HR-SBO) and are allocated with the same Visited User Plane Function (V- UPF) and the same Visited Edge Application Server Discovery Function (V-EASDF), this creates problems for the V- EASDF to distinguish these UEs / PDU sessions if these UEs are allocated with the same private IP address. Therefore, it is not possible to apply a control over these HR-SBO PDU Sessions. 3GPP Technical Specification (TS) 23.548 (see, e.g., V18.4.0) clause 67.2.2 has proposed three candidate solutions, e.g. establishing a tunnelling over N6 between the V-UPF and V-EASDF per PDU session, separate those PDU sessions sharing the same UE IP address with different network instances, and allocating a unique N6 IP address per UE / PDU session source IP address, see also the cited stage 2 requirements as reproduced below: obtain the V-EASDF IP address based on local configuration, or invoke Neasdf DNSContext Create Request including the DNN, S-NSSAI, HPLMN ID and the UE IP address set to unspecified address or to a mapped address as specified in clause 7.1.2.2 to obtain the V-EASDF IP address; andNOTE 2: The network needs to ensure thatDF can disambiguate the DNS traffic of different UEs that would be allocated with same private UE IP address. This can be done by implementation and / or deployment specific means, e g. tunnelling on N6, network instance or UE source IP address mapping. To disambiguate the DNS traffic of different UEs allocated with same private UE IP address, the V-SMF can update the Local PSA-UPF with N4 PDR and FAR including either N6 traffic routing information or network instance (as described in clause 5.6.12 of 23.501 [2]) to forward the DNS traffic to the V- EASDF. When N6 traffic routing tunnel is used, the V-SMF can configure V-EASDF with the N6 traffic routing information towards the Local PSA-UPF. Alternatively, the V-SMF can update the local UPF to translate the UE source IP address with the replaced IP address in the IP pool of the Local PSA UPF.

[0002] Accordingly, in stage 3 specification, 3GPP TS 29.556 clause 5.2.3.2.3 has further specified three candidate implementations to support Doman Name System (DNS) contexts with the same UE IP address from different Single Network Slice Assistance Information (S-NSSAI) and Data Network Names (DNNs) as follows:The following options may be used to support DNS contexts with the same (private) UE IP address from different S-NSSAI and DNNs:- the EASDF may associate a specific EASDF address with a specific S-NSSAI and DNN and provide this address to the SMF during the creation of a DNS context associated with this S-NSSAI and DNN. If so, the EASDF shall also use the destination IP address of DNS Query messages to identify the DNS context matching an incoming DNS request;- the SMF may set the UE IP address to a mapped N6 address, when using UE source IP address mapping at the Local PSA-UPF;- the SMF may provide N6 traffic routing information (in the DNS context information) that may contain the IP address and optional port number of the Local PSA-UPF, for HR-SBO in VPLMN, when using N6 tunneling between the L-PSA and V-EASDF. If so, the V-EASDF shall also use the N6 traffic routing information of DNS Query messages to identify the DNS context matching an incoming DNS request.

[0003] Furthermore, in the newly submitted Change Request (CR) #0825(04-240329) of the CT4 121 meeting, it was proposed to enable the Packet Forwarding Control Protocol (PFCP) session in the User Plane Function (UPF) to enable the tunneling or IP address replacement to support the DNS traffic routing for different UEs with the same private UE IP address as follows:To support DNS traffic routing for different UEs with same private UE IP address for HR-SBO in VPLMN as specified in clause 6.7.2.2 of 3GPP TS 23.548

[0069] , the SMF shall instruct the UPF :- to route packets according to N6 routing information in the FAR (e.g. providing the IP address and optional port number of the V-EASDF in the Outer Header Creation), when using N6 tunneling between the L-PSA UPF and V-EASDF; or- to replace the source IP address of the incoming packet with the replaced IP address in the IP pool of the Local PSA UPF, by provisioning a UL FAR with an IP Address and Port Number Replacement IE containing the replaced IP address, when using UE source IP address mapping.A UPF that supports replacing the source IP address of an (inner) IP packet shall set the IPREP flag in the UP Function Features IE (see clause 8.2.25) and shall replace the source IP address of an (inner) IP packet as instructed by the SMF.SUMMARY

[0004] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0005] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0006] There currently exist certain challenge(s) in regard to the Home Routed Session Breakout (HR-SBO) scenario for use cases in which User Equipments (UEs) from the same or different Home Public Land Mobile Networks (HPLMNs) establish Home-Routed Protocol Data Unit (PDU) sessions using the same private UE Internet Protocol (IP) address. As discussed above, if these UEs are roaming in the same Visited Public Land Mobile Network (VPLMN) that supports Home Routed-Session Break Out (HR-SBO) and are allocated with the same Visited User Plane Function (V-UPF) and the same Visited Edge Application Server Discovery Function (V-EASDF), this creates problems for the V-EASDF to distinguish these UEs / PDU sessions if these UEs are allocated with the same private IP address. 3rdGeneration Partnership Project (3GPP) Technical Specification (TS) 23.548 has proposed three candidate solutions tothis problem, namely, a N6 tunneling based solution, a network instance based solution, and a UE source IP address mapping based solution. These three candidate solutions are referred to herein Option A (N6 tunneling), Option B (network instance), and Option C (UE source IP address mapping).

[0007] For Option B, the same UE IP address can be associated with different network instances. Therefore, it is possible to distinguish the traffic towards different UEs.

[0008] For Option A, this candidate solution proposes to use N6 tunneling between the User Plane Function (UPF) and Edge Application Server Discovery Function (EASDF). As is indicated in 3GPP TSs 29.556 and 23.548, the Visited Session Management Function (V-SMF) (i.e., the Session Management Function (SMF) in the VPLMN) may provide the N6 tunneling information. How the V-SMF can obtain such N6 tunneling information is an open problem. Potentially, such information can be clarified or configured as a local configuration. However, this adds large configuration work which leads to tremendous operational cost and is difficult to maintain.

[0009] For Option C, the candidate solution proposes to replace the packets coming with the same UE IP address with the new IP address provided by the IP pool of the local PSA UPF. Again, it is clearly stated in 3GPP TSs 29.556 and 23.548, the SMF may set the UE IP address to a mapped address. Therefore, either the SMF with local configured IP pool information or the UPF controls the IP pool. If UPF provides the IP pool information, then such information shall also be given during the registration procedure and, when the SMF chooses such UPF, the IP pool information is also available to the SMF.

[0010] Therefore, both the UPF and EASDF need to contain the supported tunneling information during the Network Repository Function (NRF) discovery. While the SMF selects the UPF and then the corresponding EASDF, the tunneling information needs to be available at the SMF as well. However, in the current implementation, during the NRF discovery as defined in 3GPP 29.510 clause 6.1.6.2.15 and 6.1.6.2.77 (see below), there is no information about the tunneling information. Therefore, the SMF does not have the N6 tunnel information and cannot complete the procedure.

[0011] For Option C, the UPF needs to have the knowledge of the IP pool range during the NRF discovery for the HR- SBO. However, in 3GPP TS 29.510 clause 6.1.6.2.15 (see below), there is no such information specified.

[0012] Therefore, Option A and Option C are not complete in the current specifications and the UPF / EASDF without information of N6 tunneling and / or IP pool information is not sufficient to support the DNS traffic routing for UEs with the same IP address from multiple DNNs.

[0013] In principle, the proposal as described in C4-240329 is correct; however, the current 3GPP specifications do not define: a. How the SMF would know which IP address and port in the UPF side and which IP address and port in the EASDF side to establish such point to point N6 tunneling, i.e. to be provided in the Outer Header Creation for the tunnel IP address and port. b. How the SMF would know which IP address in the UPF can be used as the mapped N6 address for those PDU Sessions with the same private UE IP address allocated. c. How the SMF would know whether these IP address, regardless of the tunnel IP address(es) or the mapped N6 address, should ALWAYS be allocated by the SMF from a pool.

[0014] In addition, when the tunneling between the EASDF and the UPF over N6 is used for separation of different PDU sessions with the same private UE IP address, how the EASDF can be instructed to decapsulate the payload packets, e.g. DNS Query Request message, received from the tunnel (between the V-UPF and V-EASDF) and to encapsulate the payload packets, e.g. DNS query response message, into the tunnel is also a problem that needs to be solved.

[0015] For reference, the following is currently defined in 3GPP specifications:6.1.6.2.15 Type: DnnllpflnfoltemTable 6.1.6.2.15-1 : Definition of type Dnnllpflnfoltem6.1.6.2.77 Type: EasdflnfoTable 6.1.6.2.77-1 : Definition of type Easdflnfo

[0016] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.

[0017] In particular, some embodiments of the present disclosure provide a mechanism to enable the V-SMF (SMF in VPLMN) to get sufficient information to configure (i.e., set) a tunnel between the V-UPF and V-EASDF over N6 or to perform IP replacement between the Private UE IP address and a mapped N6 address, so that the V-EASDF would be able to differentiate DNS traffic from UEs with the same private IP address to apply different DNS rules for different PDU Sessions.One embodiment is directed to a method performed by Visited Session Management Function (V-SMF) in a Visited Public Land Mobile Network (VPLMN) for Home Routed (HR) Session Breakout (SBO) for a Protocol Data Unit (PDU) session of a User Equipment (UE) using a private Internet Protocol, IP, address. The method comprises: obtaining (Fig. 1, steps 5 and 6; Fig. 2, steps 1 and 2 or steps 3 and 4; Fig. 3, steps 1 and 2 or steps 3 and 4; Fig. 5, steps 1 and 2; Fig. 6, steps 1 and 2) tunneling information for establishing a tunnel between a Visited User Plane Function (V-UPF) and a Visited Edge Application Server Discovery Function (V-EASDF) (e.g., for HR-SBO of the PDU session of the UE using the private IP address); and performing (Fig. 6, step 1 or step 3; Fig. 7, step 1 and / or step 2) one or more operations based on the obtained tunneling information, the one or more operations being related to establishing a tunnel between the V-UPF and the V-EASDF (e.g., for HR-SBO of the PDU session of the UE using the private IP address).Another embodiment is directed to a method performed by a UPF. The method comprises: sending (Fig. 1, 0A) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises tunnel information for the UPF (e.g., tunnel information for establishing a tunnel between the UPF and an EASDF, e.g., for a HR-SBO PDU Session for a UE using a private IP address).Another embodiment is directed to a method performed by an Edge Application Server Discovery Function, EASDF. The method comprises: sending (Fig. 1, 0C) a request to a Network Repository Function, NRF, wherein the requestis either an NF profile registration request or an NF profile update request, and the request comprises tunnel information for the EASDF (e.g., tunnel information for establishing a tunnel between the EASDF and a UPF, e.g., for a HR-SBO PDU Session for a UE using a private IP address).Another embodiment is directed to a method performed by a V-SMF in a VPLMN, for Home Routed, HR, Session Breakout, SBO, for a PDU, session of a UE, using a private Internet Protocol, IP, address. The method comprises: obtaining (Fig. 8, steps 5 and 6) IP replacement pool information for replacement of a source IP address of the HR- SBO PDU session of the UE, which is a private UE IP address, to a mapped (e.g., N6) IP address for uplink traffic for the HR-SBO PDU session.Another embodiment is directed to a method performed by a User Plane Function (UPF). The method comprises: sending (Fig. 8, 0A) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises IP replacement pool information for the UPF (e.g., IP replacement pool information for source IP address replacement, e.g., for a HR-SBO PDU Session for a UE using a private IP address).BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.Figure 1 illustrates a procedure in which a V-UPF and a V-EASDF register their NF profiles with a NRF in a VPLMN;Figure 2 illustrates the operation of a V-SMF and a V-UPF in accordance with one example embodiment ofAlternative 1 (b1);Figure 3 illustrates the operation of a V-SMF and V-UPF in accordance with an example embodiment ofAlternative 1 (b2);Figure 4 illustrates the operation of a V-SMF and V-EASDF in accordance with an example embodiment ofAlternative 1 (d);Figure 5 illustrates the operation of a V-SMF and V-EASDF in accordance with an example embodiment ofAlternative 1 (c2);Figure 6 illustrates the operation of a V-SMF and V-EASDF in accordance with an example embodiment ofAlternative 1 (D);Figure 7 illustrates the operation of a V-UPF, V-EASDF, and V-SMF in accordance with an example embodiment of Alternative 1 (E);Figure 8 illustrates a procedure in accordance with an example embodiment of Alternative 2(A);Figure 9 illustrates a procedure in accordance with an example embodiment of Alternative 2(b1);Figure 10 illustrates a procedure in accordance with an example embodiment of Alternative 2(b2);Figure 11 illustrates a reference architecture for the 5thGeneration (5G) system (5GS);Figure 12 is a schematic block diagram of a network node 1200 according to some embodiments of the present disclosure;Figure 13 is a schematic block diagram that illustrates a virtualized embodiment of the network node 1200 according to some embodiments of the present disclosure.DETAILED DESCRIPTIONEmbodiments of the present disclosure may include any one or more of the following "Alternatives”:• Alternative 1 : The V-SMF is able to learn a range of IP addresses and optionally Port numbers for establishing a tunnel between the V-UPF and V-EASDF. This may include any one or more of the following: o Alternative 1(A): The V-UPF and V-EASDF can include such a range of IP addresses and Port numbers in their Network Function (NF) Profiles which are registered in the NRF, so that the V-SMF will get such information when the V-UPF and the V-EASDF are selected during NF (service) discovery procedure; or o Alternatives 1 (b1 ) and 1 (b2): b1. The V-UPF can report, to the SMF, a range of IP addresses and Port numbers at the V-UPF side for establishing a tunnel, e.g. via a new Information Element (IE) or an extended existing IE e.g. UE IP address Pool Information, in the PFCP Association Setup Request / Response and Update Request / Response message, when establishing I update the PFCP Association between the V-SMF and V-UPF; or b2 the V-UPF returns a tunnel IP address in the PFCP Session Establishment / Modification Response when the V-SMF establishes / updates PFCP Session for the Home Routed PDU session using a private UE IP address and indicate that the allocation of a tunneling information is required; or o Alternatives 1(c1) and 1(c2): The V-EASDF may report, to the SMF, a range of IP addresses and Port numbers at the V-EASDF side for establishing a tunnel during the Baseline DNS pattern establishment procedures; or c2. the V-EASDF may return a tunnel IP address in the DNS Context create response message when the V-SMF invokes Neasdf_DNSContext service to create an individual DNS context for the Home Routed PDU session using a private UE IP address and indicate that the allocation of a tunneling information is required; o Alternative 1(D): In corresponding to A or d , when the V-SMF selects a tunnel information at V- EASDF side, it shall indicate the selected tunnel information to the V-EASDF in the DNS Context Create or Update request message; o Alternative 1(E): In corresponding to c2 or D, the V-SMF provides instructions to the V-EASDF, so that the V-EASDF:■ retrieves the DNS Query message as the uplink payload from the tunnel (between the V- UPF and V-EASDF) by removing the outer IP header and User Datagram Protocol (UDP) header if available where the source IP address is the UPF tunnel IP and source port is theUPF port, destination IP address is the EASDF tunnel IP address and destination and port is the EASDF UDP port, and■ stores the source IP address, i.e. the UPF tunnel IP and the source port, i.e., the UPF port, to be used for downlink traffic;■ places the DNS response message as downlink payload into the tunnel (between the V- UPF and V-EASDF) by adding outer IP header where the destination IP address is the UPF tunnel IP and destination port is the UPF port.• Alternative 2: The V-SMF is able to learn a range of IP addresses and Port numbers for the IP replacement, i.e. to be able to replace the source IP address which is the private UE IP address to the mapped N6 address for Uplink traffic and replace the destination IP address which is the mapped N6 address back to the private UE IP address for downlink traffic. This may include any one or more of the following: o Alternative 2(A): The V-UPF can include such a range of IP addresses and Port numbers in their NF Profile for above purpose which is registered in the NRF, so that the SMF will get such information when the V-UPF is selected during NF (service) discovery procedure; or o Alternatives 2(b1) and 2(b2): b1. The V-UPF can report the SMF a range of IP addresses and Port numbers at the V-UPF side for IP replacement, e.g. via a new IE or an extended existing IE e.g. UE IP address Pool Information, in the PFCP Association Setup Request / Response and Update Request / Response message, when establishing I update the PFCP Association between the V-SMF and V-UPF; or b2 the V-UPF returns a mapped IP address in the PFCP Session Establishment / Modification Response when the V-SMF establishes PFCP Session for the Home Routed PDU session using a private UE IP address and indicate that the allocation of such a mapped N6 IP address is required.

[0019] Embodiments of the present disclosure may include any one or more of the following aspects:1 . Register a range of the tunnelling IP address(es) and port number information for setting up a (IP / UDP) tunnel between the UPF and EASDF for HR-SBO in the NRF for V-UPF and V-EASDF.2. Register a range of the mapped N6 IP address(es) to enable IP replacement in the NRF for V-UPF.3. The V-UPF report a range of the tunnelling IP address(es) and port number information for setting up a (IP / UDP) tunnel between the UPF and EASDF to the SMF during PFCP Association related procedure, or provide a tunnel information during establishment or modification of the PFCP session for the PDU session;4. The V-UPF report a range of the mapped N6 IP address(es) information for IP replacement to the SMF during PFCP Association related procedures, or provide a tunnel information during establishment or modification of the PFCP session for the PDU session if the SMF requested so.5. The V-EASDF report a range of the tunnelling IP address(es) and port number information for setting up a (IP / UDP) tunnel between the UPF and EASDF to the SMF during creation of DNS Baseline Patterns, or providing a tunnel information during creation of DNS Context for the individual PDU session if the SMF requested so.6. The V-EASDF is instructed by the V-SMF to decapsulate the payload packets, e.g. DNS Query Request message, received from the tunnel (between the V-UPF and V-EASDF) and to encapsulate the payload packets, e.g. DNS query response message, into the tunnel.

[0020] Certain embodiments may provide one or more of the following technical advantage(s). Embodiments of the present disclosure provide a mechanism to enable the V-SMF (SMF in VPLMN) to get sufficient information to configure / set a tunnel between the V-UPF and V-EASDF over N6 or doing IP replacement between the Private UE IP address and a mapped N6 address, so that the V-EASDF would be able to differentiate DNS traffic from UEs with the same private IP address to apply different DNS rules for different PDU Sessions.Figure 11

[0021] Figure 11 is a reproduction of Figure 4.2-5 of 3GPP TS 23.548 V18.4.0, which illustrates the reference architecture for the 5thGeneration (5G) system (5GS) providing access to an Edge Application Server (EAS) for the HR-SBO roaming scenario. Embodiments of the present disclosure may be implemented in the 5GS in accordance with the architecture of Figure 11 ; however, the embodiments of the present disclosure are not limited to the architecture of Figure 11. Further details regarding the architecture of Figure 11 can be found in, e.g., 3GPP TS 23.548.

[0022] Now, a more detailed description of embodiments of the present disclosure will be provided. This description is provided for the various "Alternatives” introduced above.Alternative 1

[0023] In Alternative 1 , the V-SMF is able to learn a range of IP addresses and optionally Port numbers for establishing a tunnel between the V-UPF and V-EASDF.Alternative 1(A):Figure 1

[0024] In Alternative 1 (A), the V-UPF and V-EASDF can include such a range of IP addresses and Port numbers in their NF Profiles, which are registered in the NRF. In this regard, Figure 1 illustrates a procedure in which a V-UPF and a V-EASDF register their NF profiles with a NRF in a VPLMN, where the NF profiles include a range of IP addresses and optionally Port numbers, in accordance with one example embodiment of Alternative 1 (A). The steps of the procedure of Figure 1 are as follows:• Step 0A: The V-UPF sends, to the NRF in the VPLMN, a NF profile registration request or an NF profile update request to register (i.e., create) or update an NF profile of the V-UPF that is stored by the NRF for the V-UPF. The NF profile the of V-UPF includes tunneling information including, e.g., a range of IP addresses and optionally a range of port numbers.• Step 0B: The NRF sends a response to the V-UPF that indicates that the NF profile of the V-UPF is successfully created or updated.• Step 0C: The V-EASDF sends, to the NRF in the VPLMN, a NF profile registration request or an NF profile update request to register (i.e., create) or update an NF profile of the V-EASDF that is stored by the NRF forthe V-EASDF. The NF profile the of V-EASDF includes tunneling information including, e.g., a range of IP addresses and optionally a range of port numbers.• Step OD: The NRF sends a response to the V-EASDF that indicates that the NF profile of the V-EASDF is successfully created or updated.• Step 1 : A UE sends, to a V-SMF, PDU session establishment request for a Home Routed (HR) PDU session.• Step 2: The V-SMF sends a PDU Session Create Request to the H-SMF (i.e., the SMF in the HPLMN) and receives a PDU Session Create Response from the H-SMF. In the response, the HR-SBO is authorized together with a VPLMN offload policy. The V-SMF learns that a private UE IP address is used.• Step 4: The V-SMF decides to select a UPF (i.e., V-UPF) and V-EASDF to support HR-SBO function.• Step 5: The V-SMF sends a discovery request to the NRF in the VPLMN. The discovery request includes at least a query parameter NF type set to UPF or EASDF.• Step 6: The NRF sends a discovery response to the V-SMF, where the discovery response includes NF profiles for one or more candidate UPFs (if NF type in discovery request set to UPF) and / or NF profiles for one or more candidate EASDFs (if NF type in discovery request set to EADF).• The V-SMF selects the V-UPF and the V-EASDF to continue with the PFCP procedure or Neasdf_DNSContextCreate Request.

[0025] Below, modified versions of the Definitions of type DnnUpflnoltem and type Easdflnfo including tunneling information is provided. Additions are shown via underlined text. This information may be included in the NF profile of the V-UPF and the NF profile of the V-EASDF, respectively.6.1.6.2.15 Type: DnnUpflnfoItemTable 6.1.6.2.15-1 : Definition of type DnnUpflnfoItem6.1.6.2.77 Type: EasdflnfoTable 6.1.6.2.77-1 : Definition of type EasdflnfoAlternative 1(b1)Figure 2

[0026] In Alternative 1 (b1), the V-UPF can report, to the V-SMF, a range of IP addresses and Port numbers at the V- UPF side for establishing a tunnel in the PFCP Association Setup Request / Response and Update Request / Responsemessage. In this regard, Figure 2 illustrates the operation of a V-SMF and a V-UPF in accordance with one example embodiment of Alternative 1 (b1).• Step 1 : The V-SMF sends a PFCP Association Setup Request to the V-UPF.• Step 2: The V-UPF sends a PFCP Association Setup Response to the V-SMF, where the PFCP Association Setup Response includes tunneling information, e.g., a range of IP addresses and optionally a range of port numbers at the V-UPF side for establishing a tunnel.• Additionally or alternatively to steps 1 and 2: o Step 3: The V-SMF sends a PFCP Association Update Request to the V-UPF. o Step 4: The V-UPF sends a PFCP Association Update Response to the V-SMF, where the PFCP Association Update Response includes (potentially updated) tunneling information, e.g., a range of IP addresses and optionally a range of port numbers at the V-UPF side for establishing a tunnel.Alternative 1 (b2)Figure 3

[0027] In Alternative 1 (b2), the V-UPF returns a tunnel IP address in the PFCP Session Establishment / Modification Response when the V-SMF establishes / updates PFCP Session for the Home Routed PDU session using a private UE IP address and indicate that the allocation of a tunneling information is required. In this regard, Figure 3 illustrates the operation of a V-SMF and V-UPF in accordance with an example embodiment of Alternative 1 (b2). The steps of the procedure are as follows:• Step 1 : The V-SMF sends, to the V-UPF. a PFCP Session Establishment request for HR-SBO PDU session using a private IP address. This request includes an indicator that the V-SMF is requesting tunnel information (e.g., requesting allocation of a tunnel information).• Step 2: The V-UPF sends a PFCP Session Establishment response to the V-SMF, where the PFCP Session Establishment response includes the requested tunnel information, e.g., a specific IP address and optionally port number for the HR-SBO PDU session.• Additionally or alternatively to steps 1 and 2: o Step 3: The V-SMF sends, to the V-UPF. a PFCP Session Modification request for the HR-SBO PDU session using the private IP address. This request includes an indicator that the V-SMF is requesting tunnel information (e.g., requesting allocation of a tunnel information). o Step 4: The V-UPF sends a PFCP Session Modification response to the V-SMF, where the PFCP Session Modification response includes the requested tunnel information, e.g., a specific IP address and optionally port number for the HR-SBO PDU session.Alternative 1(c1)Figure 4

[0028] In Alternative 1 (d), the V-EASDF may report, to the V-SMF, a range of IP addresses and Port numbers at the V-EASDF side for establishing a tunnel during the Baseline DNS pattern establishment procedures. In this regard, Figure 4 illustrates the operation of a V-SMF and V-EASDF in accordance with an example embodiment of Alternative 1 (c1). The steps of the procedure are as follows:• Step 1 : The V-SMF sends a baseline DNS pattern establishment request to the V-EASDF.• Step 2: The V-EASDF sends data about the requested baseline DSN pattern to the V-SMF, where this data includes tunneling information, e.g., a range of IP addresses and optionally a range of port numbers, from the V-EASDF.Alternative 1(c2)Figure 5

[0029] In Alternative 1 (c2), the V-EASDF may return a tunnel IP address in the DNS Context create response message when the V-SMF invokes Neasdf_DNSContext service to create an individual DNS context for the Home Routed PDU session using a private UE IP address and indicate that the allocation of a tunneling information is required. In this regard, Figure 5 illustrates the operation of a V-SMF and V-EASDF in accordance with an example embodiment of Alternative 1 (c2). The steps of the procedure are as follows:• Step 1 : The V-SMF sends, to the V-EASDF, a DNS context creation request to create an individual DNS context for a HR-SBO PDU session. This request includes an indicator that indicates that the V-SMF is requesting allocation of a tunneling information, e.g., allocation of a tunnel IP address and optionally port number.• Step 2: The V-EASDF sends, to the V-SMF, a response including the requested tunnel information, e.g., a specific IP address and optionally port number for the HR-SBO PDU session.Alternative 1(D)Figure 6

[0030] In Alternative 1 (D), in conjunction with Alternative 1 (A) or Alternative 1 (d), when the V-SMF select a tunnel information at V-EASDF side, it shall indicate to the V-EASDF in the DNS Context Create or Update request message the selected tunnel information. In this regard, Figure 6 illustrates the operation of a V-SMF and V-EASDF in accordance with an example embodiment of Alternative 1 (D). The steps of the procedure are as follows:• Step 1 : As illustrated, the V-SMF sends, to the V-EASDF, a DNS context creation request to create an individual DNS context for the HR-SBO PDU session. As illustrated, the request includes selected tunneling information, e.g., a specific tunnel IP address and optionally port number.• Step 2: The V-EASDF sends a response to the V-SMF that indicates that the requested DNS context has been created.• Additionally or alternatively to steps 1 and 2: o Step 3: The V-SMF sends, to the V-EASDF, a DNS context update request to update the individual DNS context for the HR-SBO PDU session. As illustrated, the request includes selected tunneling information, e.g., a specific tunnel IP address and optionally port number. o Step 4: The V-EASDF sends a response to the V-SMF that indicates that the requested DNS context has been updated.Alternative 1(E)Figure 7

[0031] In Alternative 1 (E), in conjunction with Alternative 1 (c2) or Alternative 1 (D), the V-SMF provides instructions to the V-EASDF to handle the payload traffic from / into the tunnel, where the instruction is at least a flag. . In this regard, Figure 7 illustrates the operation of a V-UPF, V-EASDF, and V-SMF in accordance with an example embodiment of Alternative 1 (E) . The steps of the procedure are as follows:• Step 0: After retrieving tunnel information (e.g., an IP address and optionally port number for the tunnel) either from the NRF or from the V-UPF and V-EASDF, the V-SMF needs to set up a tunnel between the V-UPF and the V-EASDF.• Step 1 : The V-SMF sends a PFCP Session Modification Request to the V-UPF and receives a corresponding PFCP Session Modification Response from the V-UPF, where the V-SMF instructs the V-UPF to put the DNS query into the tunnel towards the V-EASDF and extract the DNS response from the tunnel via Outer Header Creation and Outer Header Removal.• Step 2: The V-SMF updates the DNS context and instructs the V-EASDF to extract the DNS query from the tunnel and encapsulate the DNS response into the tunnel via a new instruction.• Step 3: A tunnel over N6 between the V-UPF and the V-EASDF is established using the retrieved tunnel information.• Step 4: The V-UPF sends an uplink payload (e.g., DNS query) encapsulated in the tunnel, where the V-UPF tunnel IP address is set as the source IP address, the V-UPF port is set as the source port, the V-EASDF tunnel IP address is set as the destination IP address, and the V-EASDF port is set as the destination port.• Step 5: When extracting payload packets from the tunnel, the V-EASDF stores the source IP address and source port (i.e., V-UPF tunnel IP address and port) to be used for downlink traffic.• Step 6: When receiving the DNS query response from the DNS server, the V-EASDF encapsulates the payload packets into the tunnel using the V-UPF tunnel IP address as the destination IP address and the V- UPF port as the destination port.• Step 7: The V-EASDF sends, to the V-UPF, the downlink payload (e.g., the DNS query response) encapsulated in the tunnel, where the V-UPF tunnel IP address is set as the destination IP address, the V-UPF port is set as the destination port, the V-EASDF tunnel IP address is set as the source IP address, and the V-EASDF port is set as the source port.Alternative 2

[0032] In Alternative 2, the V-SMF is able to learn a range of IP addresses and Port numbers for the IP replacement, i.e. to be able to replace the source IP address which is the private UE IP address to the mapped N6 address for Uplink traffic and replace the destination IP address which is the mapped N6 address back to the private UE IP address for downlink traffic.Alternative 2(A)Figure 8

[0033] In Alternative 2(A), the V-UPF can include such a range of IP addresses and Port numbers in its NF Profile for above purpose, where the NF profile is registered in the NRF so that the V-SMF will get such information when the V- UPF is selected during NF (service) discovery procedure. In this regard, Figure 8 illustrates a procedure in accordance with an example embodiment of Alternative 2(A). The steps of the procedure are as follows:• Step 0A: The V-UPF sends, to the NRF in the VPLMN, a NF profile registration request or an NF profile update request to register (i.e., create) or update an NF profile of the V-UPF that is stored by the NRF for the V-UPF. The NF profile the of V-UPF includes an IP replacement pool, e.g., a range of IP addresses and optionally a range of port numbers.• Step 0B: The NRF sends a response to the V-UPF that indicates that the NF profile of the V-UPF is successfully created or updated.• Step 1 : A UE sends, to a V-SMF, PDU session establishment request for a Home Routed (HR) PDU session.• Step 2: The V-SMF sends a PDU Session Create Request to the H-SMF (i.e., the SMF in the HPLMN) and receives a PDU Session Create Response from the H-SMF. In the response, the HR-SBO is authorized together with a VPLMN offload policy. The V-SMF learns that a private UE IP address is used.• Step 4: The V-SMF decides to select a UPF (i.e., V-UPF) to support HR-SBO function.• Step 5: The V-SMF sends a discovery request to the NRF in the VPLMN. The discovery request includes at least a query parameter NF type set to UPF.• Step 6: The NRF sends a discovery response to the V-SMF, where the discovery response includes NF profiles for one or more candidate UPFs. Here, the candidate UPFs include the V-UPF.• The V-SMF continues with the PFCP procedure to establish the PFCP session for the PDU session.Alternative 2(b1)Figure 9

[0034] In Alternative 2(bl), the V-UPF can report, to the V-SMF, a range of IP addresses and Port numbers at the V-UPF side for IP replacement, e.g. via a new IE or an extended existing IE e.g. UE IPaddress Pool Information, in the PFCP Association Setup Request / Response and Update Request / Response message, when establishing / update the PFCP Association between the V-SMF and V- UPF. In this regard, Figure 9 illustrates a procedure in accordance with an example embodiment of Alternative 2(bl). The steps of the procedure are as follows:• Step 1: The V-SMF sends a PFCP Association Setup request to the V-UPF.• Step 2: The V-UPF sends a PFCP Association Setup response to the V-SMF, where the PFCP Association Setup response includes replacement IP pool information, e.g., a range of IP addresses and optionally a range of port numbers.• Additionally or alternatively to steps 1 and 2: o Step 3: The V-SMF sends a PFCP Association Update request to the V-UPF. o Step 4: The V-UPF sends a PFCP Association Update response to the V-SMF, where the PFCP Association Update response includes replacement IP pool information, e.g., a range of IP addresses and optionally a range of port numbers.Alternative 2(b2)Figure 10

[0035] In Alternative 2(b2), the V-UPF returns a mapped IP address in the PFCP Session Establishment / Modification Response when the V-SMF establishes PFCP Session for the Home Routed PDU session using a private UE IP address and indicate that the allocation of such a mapped N6 IP address is required. In this regard, Figure 10 illustrates a procedure in accordance with an example embodiment of Alternative 2(b2). The steps of the procedure are as follows:• Step 1 : The V-SMF sends, to the V-UPF. a PFCP Session Establishment request for HR-SBO PDU session using a private IP address. This request includes an indicator that the V-SMF is requesting a mapped IP address.• Step 2: The V-UPF sends a PFCP Session Establishment response to the V-SMF, where the PFCP Session Establishment response includes the requested mapped IP address, e.g., a specific IP address and optionally port number for the HR-SBO PDU session.• Additionally or alternatively to steps 1 and 2: o Step 3: The V-SMF sends, to the V-UPF. a PFCP Session Modification request for the HR-SBO PDU session using the private IP address. This request includes an indicator that the V-SMF is requesting a mapped IP address. o Step 4: The V-UPF sends a PFCP Session Modification response to the V-SMF, were the PFCP Session Modification response includes the requested mapped IP address, e.g., a specific IP address and optionally port number for the HR-SBO PDU session.Further DescriptionFigure 12

[0036] Figure 12 is a schematic block diagram of a network node 1200 according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The network node 1200 may be, for example, a network node that implements the functionality of a Network Function (NF) or core network node such as, e.g., a V- UPF, V-SMF, V-EASDF, NRF, or the like, as described herein. As illustrated, the network node 1200 one or more processors 1204 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and / or the like), memory 1206, and a network interface 1208. The one or more processors 1204 are also referred to herein as processing circuitry. The one or more processors 1204 operate to provide one or more functions of the network node 1200 as described herein (e.g., one or more functions of a V-UPF, V-SMF, V-EASDF, NRF, or the like, as described herein). In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 1206 and executed by the one or more processors 1204.Figure 13

[0037] Figure 13 is a schematic block diagram that illustrates a virtualized embodiment of the network node 1200 according to some embodiments of the present disclosure. Again, optional features are represented by dashed boxes. As used herein, a "virtualized” network node is an implementation of the network node 1200 in which at least a portion of the functionality of the network node 1200 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, the network node 1200 includes one or more processing nodes 1300 coupled to or included as part of a network(s) 1302. Each processing node 1300 includes one or more processors 1304 (e.g., CPUs, ASICs, FPGAs, and / or the like), memory 1306, and a network interface 1308. In this example, functions 1310 of the network node 1200 described herein (one or more functions of a V-UPF, V-SMF, V-EASDF, NRF, or the like, as described herein) are implemented at the one or more processing nodes 1300 in any desired manner. In some particular embodiments, some or all of the functions 1310 of the network node 1200 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 1300. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 1300 and the control system 1202 is used in order to carry out at least some of the desired functions 1310. Notably, in some embodiments, the control system 1202 may not be included, in which case the radio unit(s) 1210 communicate directly with the processing node(s) 1300 via an appropriate network interface(s).

[0038] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the network node 1200 or a node (e.g., a processing node 1300) implementing one or more of the functions 1310 of the network node 1200 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).EMBODIMENTS

[0039] Some of the embodiments that have been described above may be summarized in the following manner:1. A method performed by Visited Session Management Function, V-SMF, in a Visited Public Land Mobile Network, PLMN, for Home Routed, HR, Session Breakout, SBO, for a Protocol Data Unit, PDU, session of a User Equipment, UE, using a private Internet Protocol, IP, address, the method comprising: obtaining (Fig. 1 , steps 5 and 6; Fig. 2, steps 1 and 2 or steps 3 and 4; Fig. 3, steps 1 and 2 or steps 3 and 4; Fig. 5, steps 1 and 2; Fig. 6, steps 1 and 2) tunneling information for establishing a tunnel between a Visited User Plane Function, V-UPF, and a Visited Edge Application Server Discovery Function, V-EASDF, (e.g., for HR-SBO of the PDU session of the UE using the private IP address); and performing (Fig. 6, step 1 or step 3; Fig. 7, step 1 and / or step 2) one or more operations based on the obtained tunneling information, the one or more operations being related to establishing a tunnel between the V-UPF and the V-EASDF (e.g., for HR-SBO of the PDU session of the UE using the private IP address).2. The method of embodiment 1 , wherein the tunneling information comprises a range of IP addresses for establishing a tunnel between the V-UPF and the V-EASDF.3. The method of embodiment 1 , wherein the tunneling information comprises a range of IP addresses and a range of ports, for establishing a tunnel between the V-UP and the V-EASDF.4. The method of any one of embodiments 1 to 3, wherein obtaining (Fig. 1 , steps 5 and 6) the tunneling information comprises: sending (Fig. 1 , step 5) a discovery request to a Network Repository Function, NRF, in the VPLMN; receiving (Fig. 1, step 6) a discovery response from the NRF, the discovery response comprising a NF profile of each of one or more candidate V-UPFs, wherein the V-UPF is a selected one of the one or more candidate V-UPFs and the NF profile of the V-UPF comprises the tunnel information.5. The method of any one of embodiments 1 to 3, wherein obtaining (Fig. 1 , steps 5 and 6) the tunneling information comprises: sending (Fig. 1 , step 5) a discovery request to a Network Repository Function, NRF, in the VPLMN; receiving (Fig. 1, step 6) a discovery response from the NRF, the discovery response comprising a NF profile of each of one or more candidate V-UPFs and each of one or more candidate V-EASDFs; wherein: the V-UPF is a selected one of the one or more candidate V-UPFs; the V-EASDF is a selected one of the one or more candidate V-EASDFs; andthe obtained tunnel information comprise first tunnel information comprised in the NF profile of the V-UPF and second tunnel information comprised in the NF profile of the V-EASDF.6. The method of any one of embodiments 1 to 3, wherein obtaining (Fig. 2, steps 1 and 2 or steps 3 and 4) the tunneling information comprises: sending (Fig. 2, step 1 or 3) a request to the V-UPF, the request being either a PFCP association setup request or a PFCP association modification request; receiving (Fig. 2, step 2 or 4) a response from the V-UPF, the response comprising the tunnel information.7. The method of any one of embodiments 1 to 3, wherein obtaining (Fig. 3, steps 1 and 2 or steps 3 and 4) the tunneling information comprises: sending (Fig. 3, step 1 or 3) a request to the V-UPF, the request being either a PFCP session establishment request or a PFCP session modification request; receiving (Fig. 3, step 2 or 4) a response from the V-UPF, the response comprising the tunnel information.8. The method of any one of embodiments 1 to 3, wherein obtaining (Fig. 4, step 2) the tunneling information comprises: receiving (Fig. 4, step 2) the tunnel information from the V-EASDF during a baseline DNS pattern establishment procedure (e.g., as part of a baseline DNS pattern creation response).9. The method of any one of embodiments 1 to 3, wherein obtaining (Fig. 5, step 2) the tunneling information comprises: receiving (Fig. 5, step 2) the tunnel information from the V-EASDF during a DNS context creation procedure (e.g., as part of a DNS context creation response).10. The method of any one of embodiments 1 to 9 (and more particularly any one of embodiments 1 to 4, or 7), wherein performing (Fig. 6, step 1 or step 3) the one or more operations based on the obtained tunneling information comprises: sending (Fig. 5, step 1 or 3) a DNS context related request to the V-EASDF, wherein the DSN context related is either a DNS context creation request or a DNS context update request and the DNS context related request comprises selected tunnel information from among the obtained tunnel information.11. The method of embodiment 10, wherein obtained tunnel information comprises a range of IP addresses, and the selected tunnel information comprise a selected IP address from the range of IP addresses.12. The method of embodiment 10, wherein obtained tunnel information comprises a range of IP addresses and a range of port numbers, and the selected tunnel information comprise a selected IP address from the range of IPaddresses and a selected port number from the range of port numbers.13. The method of any one of embodiments 1 to 12 (and more particularly any one of embodiments 8, 10, 11 , or 12), wherein performing (Fig. 6, step 1 or step 3) the one or more operations comprises: sending (Fig. 7, step 1), to the V-UPF, an instruction (e.g., in a PFCP session modification request) for the V- UPF to send an associated DNS query into the tunnel established between the V-UPF and the V-EASDF and to extract an associated DNS response from the tunnel.14. The method of any one of embodiments 1 to 13 (and more particularly any one of embodiments 8, 10, 11 , 12, or 13), wherein performing (Fig. 6, step 1 or step 3) the one or more operations comprises: sending (Fig. 7, step 2), to the V-EASDF, an instruction (e.g., in a DNS context update) for the V-EASDF to extract the associated DNS query from the tunnel established between the V-UPF and the V-EASDF and to send the associated DNS response via the tunnel.15. A network node adapted to perform the method of any one of embodiments 1 to 14.16. A method performed by a User Plane Function, UPF, the method comprises: sending (Fig. 1 , 0A) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises tunnel information for the UPF (e.g., tunnel information for establishing a tunnel between the UPF and an EASDF, e.g., for a HR-SBO PDU Session for a UE using a private IP address).17. The method of embodiment 16, wherein the tunneling information comprises a range of IP addresses for establishing a tunnel (e.g., a tunnel between the UPF and an EASDF).18. The method of embodiment 16, wherein the tunneling information comprises a range of IP addresses and a range of ports, for establishing a tunnel (e.g., a tunnel between the UPF and an EASDF).19. A network node adapted to perform the method of any one of embodiments 15 to 18.20. A method performed by an Edge Application Server Discovery Function, EASDF, the method comprises: sending (Fig. 1 , 0C) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises tunnel information for the EASDF (e.g., tunnel information for establishing a tunnel between the EASDF and a UPF, e.g., for a HR-SBO PDU Session for a UE using a private IP address).21. The method of embodiment 16, wherein the tunneling information comprises a range of IP addresses forestablishing a tunnel (e.g., a tunnel between the EASDF and a UPF).22. The method of embodiment 16, wherein the tunneling information comprises a range of IP addresses and a range of ports, for establishing a tunnel (e.g., a tunnel between the EASDF and a UPF).23. A network node adapted to perform the method of any one of embodiments 20 to 22.24. A method performed by Visited Session Management Function, V-SMF, in a Visited Public Land Mobile Network, PLMN, for Home Routed, HR, Session Breakout, SBO, for a Protocol Data Unit, PDU, session of a User Equipment, UE, using a private Internet Protocol, IP, address, the method comprising: obtaining (Fig. 8, steps 5 and 6) IP replacement pool information for replacement of a source IP address of the HR-SBO PDU session of the UE, which is a private UE IP address, to a mapped (e.g., N6) IP address for uplink traffic for the HR-SBO PDU session.25. The method of embodiment 24, further comprising performing one or more operations based on the obtained IP replacement pool, the one or more operations being related to replacing the source IP address of the HR-SBO PDU session of the UE, which is the private UE IP address, to the mapped (e.g., N6) IP address (selected from the IP replacement pool) for uplink traffic for the HR-SBO PDU session and mapping the mapped IP address back to the private UE IP address for downlink traffic for the HR-SBO PDU session.26. The method of embodiment 24 or 25, wherein the IP replacement pool information comprises a range of IP addresses.27. The method of embodiment 24 or 25, wherein the IP replacement pool information comprises a range of IP addresses and a range of ports.28. The method of any one of embodiments 24 to 27, wherein obtaining (Fig. 8, steps 5 and 6) IP replacement pool information comprises: sending (Fig. 8, step 5) a discovery request to a Network Repository Function, NRF, in the VPLMN; receiving (Fig. 8, step 6) a discovery response from the NRF, the discovery response comprising a NF profile of each of one or more candidate V-UPFs, wherein the V-UPF is a selected one of the one or more candidate V-UPFs and the NF profile of the V-UPF comprises the IP replacement pool information.29. The method of any one of embodiments 24 to 27, wherein obtaining (Fig. 8, steps 5 and 6) IP replacement pool information comprises: sending (Fig. 9, step 1 or 3) a request to the V-UPF, the request being either a PFCP association setup request or a PFCP association modification request;receiving (Fig. 9, step 2 or 4) a response from the V-UPF, the response comprising the IP replacement pool information.30. The method of any one of embodiments 24 to 27, wherein obtaining (Fig. 8, steps 5 and 6) IP replacement pool information comprises: sending (Fig. 10, step 1 or 3) a request to the V-UPF, the request being either a PFCP session establishment request or a PFCP session modification request; receiving (Fig. 10, step 2 or 4) a response from the V-UPF, the response comprising the IP replacement pool information.31. A network node adapted to perform the method of any one of embodiments 24 to 30.32. A method performed by a User Plane Function, UPF, the method comprises: sending (Fig. 8, 0A) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises IP replacement pool information for the UPF (e.g., IP replacement pool information for source IP address replacement, e.g., for a HR-SBO PDU Session for a UE using a private IP address).33. The method of embodiment 32, wherein the IP replacement pool information comprises a range of IP addresses.34. The method of embodiment 32, wherein the IP replacement pool information comprises a range of IP addresses and a range of ports.35. A network node adapted to perform the method of any one of embodiments 32 to 34.

[0040] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according to one or more embodiments of the present disclosure.

[0041] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions, and methods disclosed herein. Determining, calculating, obtaining, or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0042] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0043] While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

[0044] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

CLAIMSWhat is claimed is:

1. A method performed by Visited Session Management Function, V-SMF, in a Visited Public Land Mobile Network, PLMN, for Home Routed, HR, Session Breakout, SBO, for a Protocol Data Unit, PDU, session of a User Equipment, UE, using a private Internet Protocol, IP, address, the method comprising: obtaining (Fig. 1 , steps 5 and 6; Fig. 2, steps 1 and 2 or steps 3 and 4; Fig. 3, steps 1 and 2 or steps 3 and 4; Fig. 5, steps 1 and 2; Fig. 6, steps 1 and 2) tunneling information for establishing a tunnel between a Visited User Plane Function, V-UPF, and a Visited Edge Application Server Discovery Function, V-EASDF, (e.g., for HR-SBO of the PDU session of the UE using the private IP address); and performing (Fig. 6, step 1 or step 3; Fig. 7, step 1 and / or step 2) one or more operations based on the obtained tunneling information, the one or more operations being related to establishing a tunnel between the V-UPF and the V-EASDF (e.g., for HR-SBO of the PDU session of the UE using the private IP address).

2. The method of claim 1, wherein the tunneling information comprises a range of IP addresses for establishing a tunnel between the V-UPF and the V-EASDF.

3. The method of claim 1 , wherein the tunneling information comprises a range of IP addresses and a range of ports, for establishing a tunnel between the V-UP and the V-EASDF.

4. The method of any one of claim 1 to 3, wherein obtaining (Fig. 1, steps 5 and 6) the tunneling information comprises: sending (Fig. 1 , step 5) a discovery request to a Network Repository Function, NRF, in the VPLMN; receiving (Fig. 1 , step 6) a discovery response from the NRF, the discovery response comprising a NF profile of each of one or more candidate V-UPFs, wherein the V-UPF is a selected one of the one or more candidate V-UPFs and the NF profile of the V-UPF comprises the tunnel information.

5. The method of any one of claim 1 to 3, wherein obtaining (Fig. 1, steps 5 and 6) the tunneling information comprises: sending (Fig. 1 , step 5) a discovery request to a Network Repository Function, NRF, in the VPLMN; receiving (Fig. 1 , step 6) a discovery response from the NRF, the discovery response comprising a NF profile of each of one or more candidate V-UPFs and each of one or more candidate V-EASDFs; wherein: the V-UPF is a selected one of the one or more candidate V-UPFs; the V-EASDF is a selected one of the one or more candidate V-EASDFs; and the obtained tunnel information comprise first tunnel information comprised in the NF profile of the V-UPF and second tunnel information comprised in the NF profile of the V-EASDF.

6. The method of any one of claim 1 to 3, wherein obtaining (Fig. 2, steps 1 and 2 or steps 3 and 4) the tunneling information comprises: sending (Fig. 2, step 1 or 3) a request to the V-UPF, the request being either a PFCP association setup request or a PFCP association modification request; receiving (Fig. 2, step 2 or 4) a response from the V-UPF, the response comprising the tunnel information.

7. The method of any one of claim 1 to 3, wherein obtaining (Fig. 3, steps 1 and 2 or steps 3 and 4) the tunneling information comprises: sending (Fig. 3, step 1 or 3) a request to the V-UPF, the request being either a PFCP session establishment request or a PFCP session modification request; receiving (Fig. 3, step 2 or 4) a response from the V-UPF, the response comprising the tunnel information.

8. The method of any one of claim 1 to 3, wherein obtaining (Fig. 4, step 2) the tunneling information comprises: receiving (Fig. 4, step 2) the tunnel information from the V-EASDF during a baseline DNS pattern establishment procedure (e.g., as part of a baseline DNS pattern creation response).

9. The method of any one of claim 1 to 3, wherein obtaining (Fig. 5, step 2) the tunneling information comprises: receiving (Fig. 5, step 2) the tunnel information from the V-EASDF during a DNS context creation procedure(e.g., as part of a DNS context creation response).

10. The method of any one of claim 1 to 9 (and more particularly any one of claim 1 to 4, or 7), wherein performing (Fig. 6, step 1 or step 3) the one or more operations based on the obtained tunneling information comprises: sending (Fig. 5, step 1 or 3) a DNS context related request to the V-EASDF, wherein the DSN context related is either a DNS context creation request or a DNS context update request and the DNS context related request comprises selected tunnel information from among the obtained tunnel information.

11. The method of claim 10, wherein obtained tunnel information comprises a range of IP addresses, and the selected tunnel information comprise a selected IP address from the range of IP addresses.

12. The method of claim 10, wherein obtained tunnel information comprises a range of IP addresses and a range of port numbers, and the selected tunnel information comprise a selected IP address from the range of IP addresses and a selected port number from the range of port numbers.

13. The method of any one of claim 1 to 12 (and more particularly any one of claim 8, 10, 11, or 12), wherein performing (Fig. 6, step 1 or step 3) the one or more operations comprises: sending (Fig. 7, step 1), to the V-UPF, an instruction (e.g., in a PFCP session modification request) for the V- UPF to send an associated DNS query into the tunnel established between the V-UPF and the V-EASDF and to extractan associated DNS response from the tunnel.

14. The method of any one of claim 1 to 13 (and more particularly any one of claim 8, 10, 11, 12, or 13), wherein performing (Fig. 6, step 1 or step 3) the one or more operations comprises: sending (Fig. 7, step 2), to the V-EASDF, an instruction (e.g., in a DNS context update) for the V-EASDF to extract the associated DNS query from the tunnel established between the V-UPF and the V-EASDF and to send the associated DNS response via the tunnel.

15. A network node adapted to perform the method of any one of claim 1 to 14.

16. A method performed by a User Plane Function, UPF, the method comprises: sending (Fig. 1, 0A) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises tunnel information for the UPF (e.g., tunnel information for establishing a tunnel between the UPF and an EASDF, e.g., for a HR-SBO PDU Session for a UE using a private IP address).

17. The method of claim 16, wherein the tunneling information comprises a range of IP addresses for establishing a tunnel (e.g., a tunnel between the UPF and an EASDF).

18. The method of claim 16, wherein the tunneling information comprises a range of IP addresses and a range of ports, for establishing a tunnel (e.g., a tunnel between the UPF and an EASDF).

19. A network node adapted to perform the method of any one of claim 15 to 18.

20. A method performed by an Edge Application Server Discovery Function, EASDF, the method comprises: sending (Fig. 1, 0C) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises tunnel information for the EASDF (e.g., tunnel information for establishing a tunnel between the EASDF and a UPF, e.g., for a HR-SBO PDU Session for a UE using a private IP address).

21. The method of claim 16, wherein the tunneling information comprises a range of IP addresses for establishing a tunnel (e.g., a tunnel between the EASDF and a UPF).

22. The method of claim 16, wherein the tunneling information comprises a range of IP addresses and a range of ports, for establishing a tunnel (e.g., a tunnel between the EASDF and a UPF).

23. A network node adapted to perform the method of any one of claim 20 to 22.

24. A method performed by Visited Session Management Function, V-SMF, in a Visited Public Land Mobile Network, PLMN, for Home Routed, HR, Session Breakout, SBO, for a Protocol Data Unit, PDU, session of a User Equipment, UE, using a private Internet Protocol, IP, address, the method comprising: obtaining (Fig. 8, steps 5 and 6) IP replacement pool information for replacement of a source IP address of the HR-SBO PDU session of the UE, which is a private UE IP address, to a mapped (e.g., N6) IP address for uplink traffic for the HR-SBO PDU session.

25. The method of claim 24, further comprising performing one or more operations based on the obtained IP replacement pool, the one or more operations being related to replacing the source IP address of the HR-SBO PDU session of the UE, which is the private UE IP address, to the mapped (e.g., N6) IP address (selected from the IP replacement pool) for uplink traffic for the HR-SBO PDU session and mapping the mapped IP address back to the private UE IP address for downlink traffic for the HR-SBO PDU session.

26. The method of claim 24 or 25, wherein the IP replacement pool information comprises a range of IP addresses.

27. The method of claim 24 or 25, wherein the IP replacement pool information comprises a range of IP addresses and a range of ports.

28. The method of any one of claim 24 to 27, wherein obtaining (Fig. 8, steps 5 and 6) IP replacement pool information comprises: sending (Fig. 8, step 5) a discovery request to a Network Repository Function, NRF, in the VPLMN; receiving (Fig. 8, step 6) a discovery response from the NRF, the discovery response comprising a NF profile of each of one or more candidate V-UPFs, wherein the V-UPF is a selected one of the one or more candidate V-UPFs and the NF profile of the V-UPF comprises the IP replacement pool information.

29. The method of any one of claim 24 to 27, wherein obtaining (Fig. 8, steps 5 and 6) IP replacement pool information comprises: sending (Fig. 9, step 1 or 3) a request to the V-UPF, the request being either a PFCP association setup request or a PFCP association modification request; receiving (Fig. 9, step 2 or 4) a response from the V-UPF, the response comprising the IP replacement pool information.

30. The method of any one of claim 24 to 27, wherein obtaining (Fig. 8, steps 5 and 6) IP replacement pool information comprises: sending (Fig. 10, step 1 or 3) a request to the V-UPF, the request being either a PFCP sessionestablishment request or a PFCP session modification request; receiving (Fig. 10, step 2 or 4) a response from the V-UPF, the response comprising the IP replacement pool information.

31. A network node adapted to perform the method of any one of claim 24 to 30.

32. A method performed by a User Plane Function, UPF, the method comprises: sending (Fig. 8, 0A) a request to a Network Repository Function, NRF, wherein the request is either an NF profile registration request or an NF profile update request, and the request comprises IP replacement pool information for the UPF (e.g., IP replacement pool information for source IP address replacement, e.g., for a HR-SBO PDU Session for a UE using a private IP address).

33. The method of claim 32, wherein the IP replacement pool information comprises a range of IP addresses.

34. The method of claim 32, wherein the IP replacement pool information comprises a range of IP addresses and a range of ports.

35. A network node adapted to perform the method of any one of claim 32 to 34.

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