WO2023203365A1

WO2023203365A1 - General packet radio service tunneling protocol (gtp) path management enhancement towards cloud native peers

Info

Publication number: WO2023203365A1
Application number: PCT/IB2022/053713
Authority: WO
Inventors: Jeonghoon Choi; Åke TÖRNKVIST; Patrik Herneld; Andrzej JURCZAK
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-04-20
Filing date: 2022-04-20
Publication date: 2023-10-26

Abstract

A method performed by a general packet radio service tunneling protocol (GTP) initiator to determine a reachability status of GTP responders that belong to a same subnetwork. The method includes sending a GTP echo request message that includes a peer subnetwork information element to each of a plurality of GTP responders, responsive to receiving a GTP echo response message including a peer subnetwork information element from at least two of the plurality of GTP responders, selecting one of the at least two GTP responders to be a representative GTP responder, and sending further GTP echo request messages to the representative GTP responder to determine the reachability status of the at least two GTP responders without sending GTP echo request messages to others of the at least two GTP responders that were not selected to be a representative GTP responder.

Description

SPECIFICATION

GENERAL PACKET RADIO SERVICE TUNNELING PROTOCOL (GTP) PATH MANAGEMENT ENHANCEMENT TOWARDS CLOUD NATIVE PEERS

TECHNICAL FIELD

[0001] Embodiments of the invention relate to the field of communication networks, and more specifically, to efficiently determining the reachability status of General Packet Radio Service Tunneling Protocol (GTP) responders that belong to the same subnetwork.

BACKGROUND

[0002] The General Packet Radio Service (GPRS) Tunneling Protocol (GTP) is a tunneling protocol defined by Third Generation Partnership Project (3 GPP) standards to tunnel packets within mobile networks. GTP includes GTP User Plane (GTP-U), which is used for carrying user data within the core network (e.g., an Evolved Packet Core (EPC) or a Fifth Generation Core (5GC)) and between the radio access network (RAN) and the core network.

[0003] GTP-U may involve sending signaling messages such as path management messages. Path management messages include GTP echo request messages and GTP echo response messages. A first GTP-U peer may send a GTP echo request message to a second GTP-U peer to determine the reachability status of the second GTP-U peer. If the second GTP-U peer receives the GTP echo request message from the first GTP-U peer, then the second GTP-U peer sends a GTP echo response message to the first GTP-U peer. The first GTP-U peer may determine the reachability status of the second GTP-U peer (and thus the health of the GTP path to the second GTP-U peer) based on whether it received a GTP echo response message from the second GTP-U peer.

[0004] The term “cloud native” refers to the concept of building and running applications in the cloud that take advantage of the scalability, elasticity, resiliency, and/or flexibility provided by a cloud computing architecture.

[0005] Many mobile network operators are embracing the use of cloud native technologies in their mobile networks. For example, mobile network operators are deploying cloud native equipment based on commercial off-the-shelf (COTS) hardware in the core network and/or in the RAN. The use of cloud native technologies allows the mobile network operators to introduce new services in their mobile networks more quickly and allows the mobile networks to scale more efficiently in response to user demand. [0006] Mobile network deployments that use cloud native technology typically use more Internet Protocol (IP) addresses compared to mobile network deployments that do not use cloud native technology, as IP addresses are assigned per virtual machine (VM). GTP paths are created for each local IP address and remote IP address pair. As such, in mobile network deployments that use cloud native technology, the number of GTP paths that network entities (e.g., radio nodes) need to manage increases dramatically, which results in consuming more CPU resources and bandwidth.

SUMMARY

[0007] A method performed by a general packet radio service tunneling protocol (GTP) initiator to determine a reachability status of GTP responders that belong to a same subnetwork is disclosed. The method includes sending a GTP echo request message that includes a peer subnetwork information element to each of a plurality of GTP responders, responsive to receiving a GTP echo response message including a peer subnetwork information element from at least two of the plurality of GTP responders, selecting one of the at least two GTP responders to be a representative GTP responder, and sending further GTP echo request messages to the representative GTP responder to determine the reachability status of the at least two GTP responders without sending GTP echo request messages to others of the at least two GTP responders that were not selected to be a representative GTP responder.

[0008] A non-transitory machine-readable storage medium that provides instructions that, if executed by a processor of a network device implementing a GTP initiator, causes the GTP initiator to carry out operations for determining a reachability status of GTP responders that belong to a same subnetwork is disclosed. The operations include sending a GTP echo request message that includes a peer subnetwork information element to each of a plurality of GTP responders, responsive to receiving a GTP echo response message including a peer subnetwork information element from at least two of the plurality of GTP responders, selecting one of the at least two GTP responders to be a representative GTP responder, and sending further GTP echo request messages to the representative GTP responder to determine the reachability status of the at least two GTP responders without sending GTP echo request messages to others of the at least two GTP responders that were not selected to be a representative GTP responder.

[0009] A method performed by a GTP responder from a plurality of GTP responders belonging to a same subnetwork is disclosed. The method includes receiving a GTP echo request message from a GTP initiator and responsive to a determination that the GTP echo request message includes a peer subnetwork information element, sending a GTP echo response message that includes a peer subnetwork information element to the GTP initiator. [0010] A non-transitory machine-readable storage medium that provides instructions that, if executed by a processor of a network device implementing a GTP responder, causes the GTP responder to carry out operations including receiving a GTP echo request message from a GTP initiator and responsive to a determination that the GTP echo request message includes a peer subnetwork information element, sending a GTP echo response message that includes a peer subnetwork information element to the GTP initiator.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:

[0012] Figure l is a diagram showing an example environment in which efficient GTP path management can be implemented, according to some embodiments.

[0013] Figure 2 is a diagram showing component interactions for providing efficient GTP path management, according to some embodiments.

[0014] Figure 3 is a diagram showing formats of a GTP echo request message and a GTP echo response message, according to some embodiments.

[0015] Figure 4 is a diagram showing components of a GTP initiator, according to some embodiments.

[0016] Figure 5 is a diagram showing components of a GTP responder, according to some embodiments.

[0017] Figure 6 is a flow diagram of a method performed by a GTP initiator for determining a reachability status of a plurality of GTP responders that belong to the same subnetwork, according to some embodiments.

[0018] Figure 7 is a flow diagram of a method performed by a GTP responder, according to some embodiments.

[0019] Figure 8 is a diagram showing an example of a communication system, according to some embodiments.

[0020] Figure 9 is a diagram showing a network node, according to some embodiments. [0021] Figure 10 is a diagram showing a virtualization environment in which functions implemented by some embodiments may be virtualized. DETAILED DESCRIPTION

[0022] The following description describes methods and apparatus for efficiently determining the reachability status of General Packet Radio Service Tunneling Protocol (GTP) responders that belong to the same subnetwork. In the following description, numerous specific details such as logic implementations, opcodes, means to specify operands, resource partitioning/sharing/duplication implementations, types and interrelationships of system components, and logic partitioning/integration choices are set forth in order to provide a more thorough understanding of the present invention. It will be appreciated, however, by one skilled in the art that the invention may be practiced without such specific details. In other instances, control structures, gate level circuits and full software instruction sequences have not been shown in detail in order not to obscure the invention. Those of ordinary skill in the art, with the included descriptions, will be able to implement appropriate functionality without undue experimentation.

[0023] References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0024] Bracketed text and blocks with dashed borders (e.g., large dashes, small dashes, dotdash, and dots) may be used herein to illustrate optional operations that add additional features to embodiments of the invention. However, such notation should not be taken to mean that these are the only options or optional operations, and/or that blocks with solid borders are not optional in certain embodiments of the invention.

[0025] In the following description and claims, the terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. “Coupled” is used to indicate that two or more elements, which may or may not be in direct physical or electrical contact with each other, co-operate or interact with each other. “Connected” is used to indicate the establishment of communication between two or more elements that are coupled with each other.

[0026] An electronic device stores and transmits (internally and/or with other electronic devices over a network) code (which is composed of software instructions and which is sometimes referred to as computer program code or a computer program) and/or data using machine-readable media (also called computer-readable media), such as machine-readable storage media (e.g., magnetic disks, optical disks, solid state drives, read only memory (ROM), flash memory devices, phase change memory) and machine-readable transmission media (also called a carrier) (e.g., electrical, optical, radio, acoustical or other form of propagated signals - such as carrier waves, infrared signals). Thus, an electronic device (e.g., a computer) includes hardware and software, such as a set of one or more processors (e.g., wherein a processor is a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, other electronic circuitry, a combination of one or more of the preceding) coupled to one or more machine-readable storage media to store code for execution on the set of processors and/or to store data. For instance, an electronic device may include non-volatile memory containing the code since the non-volatile memory can persist code/data even when the electronic device is turned off (when power is removed), and while the electronic device is turned on that part of the code that is to be executed by the processor(s) of that electronic device is typically copied from the slower nonvolatile memory into volatile memory (e.g., dynamic random access memory (DRAM), static random access memory (SRAM)) of that electronic device. Typical electronic devices also include a set of one or more physical network interface(s) (NI(s)) to establish network connections (to transmit and/or receive code and/or data using propagating signals) with other electronic devices. For example, the set of physical NIs (or the set of physical NI(s) in combination with the set of processors executing code) may perform any formatting, coding, or translating to allow the electronic device to send and receive data whether over a wired and/or a wireless connection. In some embodiments, a physical NI may comprise radio circuitry capable of receiving data from other electronic devices over a wireless connection and/or sending data out to other devices via a wireless connection. This radio circuitry may include transmitted s), received s), and/or transceiver(s) suitable for radiofrequency communication. The radio circuitry may convert digital data into a radio signal having the appropriate parameters (e.g., frequency, timing, channel, bandwidth, etc.). The radio signal may then be transmitted via antennas to the appropriate recipient(s). In some embodiments, the set of physical NI(s) may comprise network interface controlled s) (NICs), also known as a network interface card, network adapter, or local area network (LAN) adapter. The NIC(s) may facilitate in connecting the electronic device to other electronic devices allowing them to communicate via wire through plugging in a cable to a physical port connected to a NIC. One or more parts of an embodiment of the invention may be implemented using different combinations of software, firmware, and/or hardware.

[0027] A network device (ND) is an electronic device that communicatively interconnects other electronic devices on the network (e.g., other network devices, end-user devices). Some network devices are “multiple services network devices” that provide support for multiple networking functions (e.g., routing, bridging, switching, Layer 2 aggregation, session border control, Quality of Service, and/or subscriber management), and/or provide support for multiple application services (e.g., data, voice, and video).

[0028] As mentioned above, mobile network deployments that use cloud native technology typically use more Internet Protocol (IP) addresses compared to mobile network deployments that do not use cloud native technology. GTP paths are created for each local IP address and remote IP address pair. As such, in mobile network deployments that use cloud native technology, the number of GTP paths that network entities (e.g., radio nodes) need to manage increases dramatically, which results in consuming more CPU resources and bandwidth.

[0029] Embodiments disclosed herein improve the efficiency of GTP path management based on a recognition that in mobile network deployments that use cloud native technology, there is a high probability that GTP paths will be created between a single GTP initiator and multiple GTP responders belonging to the same subnetwork (e.g., because multiple GTP responders will be implemented in the same virtual machine (VM) and/or datacenter). These GTP paths will have the same/similar paths to a remote cloud native equipment/datacenter. As such, the reachability status of the GTP responders is expected to be the same or similar. Actively managing all of these GTP paths may be redundant and may add unnecessary traffic load to the transport network and/or increase the CPU usage of the network entities involved in GTP path management. Embodiments disclosed herein reduce the traffic load and/or the CPU usage of network entities involved in GTP path management by selecting one of the GTP responders to be a representative GTP responder and determining the reachability status of multiple GTP responders belonging to the same subnetwork based on GTP path management messages exchanged with the representative GTP responder. For this purpose, embodiments disclosed herein introduce a new information element referred to herein as a “peer subnetwork” information element that can be included in GTP path management messages to obtain/provide information regarding GTP responders such as the IP address and subnet mask of the GTP responders.

[0030] According to some embodiments, a GTP initiator sends a GTP echo request message that includes a peer subnetwork information element to each of a plurality of GTP responders that belong to the same subnetwork. The inclusion of the peer subnetwork information element in the GTP echo request message indicates to the GTP responder that the GTP responder is to provide certain information regarding the GTP responder such as the IP address and subnet mask of the GTP responder in the corresponding GTP echo response message. Each GTP responder that successfully receives a GTP echo request message including a peer subnetwork information element may respond by sending a GTP echo response message that includes a peer subnetwork information element to the GTP initiator, where this peer subnetwork information element includes an indication of the IP address and the subnet mask of the GTP responder. The GTP initiator may then select one of the GTP responders that belong to the same subnetwork (and that responded to the GTP echo request message) to be a representative GTP responder. The GTP initiator may then continue to send further GTP echo request messages to the representative GTP responder to determine the reachability status of other GTP responders belonging to the same subnetwork as the representative GTP responder without sending GTP echo request messages to the other GTP responders (i.e., without sending GTP echo request messages to the GTP responders that were not selected to be the representative GTP responder). [0031] Embodiments disclosed herein provide one or more technical advantages over conventional GTP path management approaches. For example, by selecting a representative GTP responder and sending GTP echo request messages only to the representative GTP responder, embodiments avoid having to actively manage multiple GTP paths. This helps reduce the amount of packet processing load and/or CPU usage of the GTP initiator and the GTP responders. Also, this helps reduce bandwidth consumption in the mobile network (e.g., in the transport network and/or the core network) by reducing the number of path management messages (e.g., echo request messages and echo response messages) that are sent in the mobile network. Also, troubleshooting can be simplified when a problem occurs. Other technical benefits/advantages will be apparent to those skilled in the art in view of the present disclosure. Various embodiments are now described with reference to the accompanying figures.

[0032] Figure l is a diagram showing an example environment in which efficient GTP path management can be implemented, according to some embodiments.

[0033] As shown in the diagram, the environment includes radio nodes 110A-N, a transport network 160, and datacenters 120 A and 120B. The radio nodes 110A-N may wirelessly communicate with multiple UEs (user equipment - not shown) to provide the UEs with access to the core of a mobile network (a core network such as an Evolved Packet Core (EPC) or a Fifth Generation Core (5GC)). The radio nodes 110A-N may be communicatively coupled to the datacenters 120 via the transport network 160. In an embodiment, a radio node 110 may be an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (EUTRAN) or a Next Generation Radio Access Network (NG-RAN).

[0034] The transport network 160 facilitates communications between the radio nodes 110A-N and the datacenters 120. As shown in the diagram, the transport network 160 may include a router 170 that routes network traffic between the radio nodes 110A-N and the datacenters 120. [0035] The datacenters 120 may implement various functionalities of a core network using a cloud native approach. Each datacenter 120 may implement one or more VMs 130. For example, as shown in the diagram, datacenter 120 A implements VM 130A (and possibly one or more additional VMs 130) and datacenter 120B implements VM 130B (and possibly one or more additional VMs 130). Each VM 130 may implement one or more core network nodes. For example, as shown in the diagram, VM 130A implements SGW 140 (and possibly one or more additional SGWs 140) and VM 130B implements UPF 145 A (and possibly one or more additional UPFs 145). In the example shown in the diagram, datacenter 120 A implements core network nodes of an EPC (e.g., SGWs 140), while datacenter 120B implements core network nodes of a 5GC (e.g., UPFs 145).

[0036] The core network nodes that are implemented in the same VM 130 and/or datacenter 120 may be assigned different IP addresses but belong to the same subnetwork. For example, the SGWs 140 implemented in datacenter 120A may each be assigned different IP addresses but belong to the same subnetwork. Similarly, the UPFs 145 implemented in datacenter 120B may each be assigned different IP addresses but belong to the same subnetwork.

[0037] Each datacenter 120 may include a switch 150 to forward network traffic entering the datacenter 120 and/or forward network traffic leaving the datacenter 120. For example, as shown in the diagram, datacenter 120A includes switch 150A and datacenter 120B includes switch 150B.

[0038] A GTP path may be created between a radio node 110 and one or more core network nodes implemented in the datacenters 120. For example, as shown in the diagram, a GTP path is created between radio node 110A and the SGWs 140 implemented in datacenter 120 A (e.g., including SGW 140A). Also, as shown in the diagram, a GTP path is created between radio node 110N and the UPFs 145 implemented in datacenter 120B (e.g., including UPF 145A). In an embodiment, GTP paths can be created between a radio node 110 and core network nodes implemented across different datacenters 120. For example, as shown in the diagram, a GTP path can be created between radio node 110A and UPF 145 A (and possibly additional UPFs 145) implemented in datacenter 120B. Similarly, a GTP path can be created between radio node 110N and SGW 140 A (and possibly additional SGWs 140) implemented in datacenter 120B.

[0039] The diagram shows an environment having a particular configuration of components to help illustrate a particular embodiment. It should be understood that other embodiments may have a different configuration. [0040] Radio nodes 110 and core network nodes (e.g., the SGWs 140 and/or UPFs 145) may exchange GTP path management messages 180 with each other as part of performing GTP path management. Examples of GTP path management messages 180 include GTP echo request messages and GTP echo response messages. The entity sending the GTP echo request message may be referred to herein as the GTP initiator and the entity that is to receive the GTP echo request message (the intended recipient of the GTP echo request message) may referred to herein as the GTP responder. As shown in the diagram, in an embodiment, a GTP path management message 180 may include a peer subnetwork information element 185. A GTP initiator may include a peer subnetwork information element 185 in a GTP echo request message it sends to a GTP responder to indicate to the GTP responder that the GTP responder is to include a peer subnetwork information element 185 in the corresponding GTP echo response message that the GTP responder sends to the GTP initiator. A GTP responder that receives a GTP echo request message that includes a peer subnetwork information element 185 may include a peer subnetwork information element 185 in the corresponding GTP echo response message that the GTP responder sends to the GTP initiator. The GTP responder may indicate various information regarding the GTP responder in the peer subnetwork information element 185 such as the IP address and subnet mask of the GTP responder. As used herein, the term “subnet mask” may refer to an IPv4 subnet mask, an IPv6 prefix length, or other type of construct that is used to logically subdivide a network.

[0041] For sake of illustration, various examples are shown and described herein where the radio nodes 110 are GTP initiators and the core network nodes are the GTP responders. However, it should be understood that embodiments are not so limited. In some embodiments, the core network nodes may be the GTP initiators and the radio nodes may be the GTP responders. Also, in some embodiments, GTP paths may be created between core network nodes (e.g., between SGWs 140), and these core network nodes may use the techniques disclosed herein to perform efficient GTP path management with each other.

[0042] In an embodiment, as part of performing path management, a GTP requestor sends a GTP echo request message including a peer subnetwork information element 185 to each GTP responder. As mentioned above, the inclusion of the peer subnetwork information element 185 in the GTP echo request message indicates to the GTP responders that they are to include a peer subnetwork information element 185 in the corresponding GTP echo response message.

[0043] If a GTP responder successfully receives a GTP echo request message including a peer subnetwork information element 185, the GTP responder may determine its own IP address and subnet mask. The GTP responder may then send a GTP echo response message that includes a peer subnetwork information element 185 to the GTP initiator (as a response to the GTP echo request message that the GTP responder received from the GTP initiator), where the peer subnetwork information element 185 indicates the IP address and the subnet mask of the GTP responder. In an embodiment, the GTP responder includes an indication of a preferred IP address in the peer subnetwork information element 185, where the preferred IP address is the IP address of the GTP responder that is designated as being a preferred representative GTP responder (it is preferred that this GTP responder is selected to be the representative GTP responder, assuming all else is equal). As will be described in additional detail below, the GTP initiator may take this information into account when selecting the representative GTP responder. Additionally or alternatively, in an embodiment, the GTP responder includes an indication of an operational state of the GTP responder in the peer subnetwork information element 185. The operational state of the GTP responder may indicate, for example, whether the GTP responder is operating normally or not. As will be described in additional detail below, the GTP initiator may take this information into account when selecting the representative GTP responder. Additionally or alternatively, in an embodiment, the GTP responder includes an indication of an ID associated with the GTP responder in the peer subnetwork information element 185. The ID may be an ID that uniquely identifies the GTP responder in the mobile network such as a Universally Unique Identifier (UUID). As will be described in additional detail below, the GTP initiator may take this information into account when selecting the representative GTP responder. An example format of a peer subnetwork information element is shown in Figure 3.

[0044] Subsequently, the GTP initiator may determine which of the GTP responders responded with a GTP echo response message that included a peer subnetwork information element 185. The GTP initiator may store information regarding those GTP responders (e.g., information indicated in the peer subnetwork information elements 185 included in the GTP echo responses messages sent by those GTP responders) in a repository. In an embodiment, if the GTP initiator does not receive a GTP echo response message from a particular GTP responder or receives a GTP echo response message that does not include a peer subnetwork information element 185 from the particular GTP responder, the GTP initiator may actively manage the GTP path to that GTP responder using a conventional GTP path management approach (e.g., by sending separate GTP echo request messages to that GTP responder).

[0045] The GTP initiator may then select one of the GTP responders belonging to the same subnetwork that responded to the GTP echo request message (with a GTP echo response message that included a peer subnetwork information element 185) to be a representative GTP responder. In an embodiment, the GTP initiator takes information indicated in the peer subnetwork information elements included in the GTP echo responses into account when selecting the representative GTP responder. For example, if a peer subnetwork information element included in one or more of the GTP echo response messages indicates a particular preferred IP address, then the GTP initiator may select the GTP responder having the particular preferred IP address to be the representative GTP responder if possible/appropriate. As another example, if a peer subnetwork information element included in a GTP echo response message received from a GTP responder indicates that the operational state of that GTP responder is “abnormal” then the GTP initiator may avoid selecting that GTP responder as a representative GTP responder. In certain mobile networks (e.g., 5G mobile networks), multiple SGWs/UPFs can have the same ID (e.g., a UUTD) if they belong to the same network function (NF) instance in a datacenter. Thus, in an embodiment, if a peer subnetwork information elements included in GTP echo response messages received from multiple GTP responder indicate the same ID, then the GTP initiator may select one of those GTP responders to be a representative GTP responder. In an embodiment, the ID associated with a GTP responder is indicated in a reserved field of the peer subnetwork information element.

[0046] Once the GTP initiator has selected a representative GTP responder, the GTP initiator may continue sending further GTP echo request messages to the representative GTP responder to determine the reachability status of the representative GTP responder as well as the status of other GTP responders that belong to the same subnetwork as the representative GTP responder (e.g., the GTP responders that responded with a GTP echo response message that included a peer subnetwork information element 185 but were not selected to be a representative GTP responder) without sending further GTP echo request messages to the other GTP responders. [0047] If the GTP initiator subsequently determines that information regarding the representative GTP responder has changed (e.g., the IP address of the GTP responder, the subnet mask of the GTP responder, the operational state of the GTP responder, and/or the preferred IP address indicated by the GTP responder has changed), then the GTP initiator may restart the process to potentially select a new representative GTP responder.

[0048] By way of example, referring to Figure 1, radio node 110A may send a GTP echo request message including a peer subnetwork information element 185 to each of the SGWs 140 implemented in datacenter 120 A to which radio node 110A has a GTP path (e.g., via the router 170 included in the transport network 160 and switch 150 A included in datacenter 120A). In this example, radio node 110A is the GTP initiator and the SGWs 140 are the GTP responders. A SGW 140 that receives the GTP echo request message may determine its own IP address and subnet mask. The SGW 140 may then send a GTP echo response message that includes a peer subnetwork information element 185 to radio node 110A (as a response to the GTP echo request message sent by radio node 110A) (e.g., via switch 150A and the router 170), where the peer subnetwork information element 185 includes an indication of the IP address and subnet mask of the SGW 140. Subsequently, the radio node 110A may determine which of the SGWs 140 responded with a GTP echo response message that includes a peer subnetwork information element 185. The radio node 110A may store information regarding those SGWs 140 (e.g., information indicated in the peer subnetwork information elements 185 included in the GTP echo response messages sent by those SGWs 140 (e.g., IP address and subnet mask information)) in a repository. Radio node 110A may then select one of the SGWs 140 that responded with a GTP echo response message that included a peer subnetwork information element 185 to be the representative GTP responder. In this example, radio node 110A selects SGW 140 A to be the representative GTP responder. Radio node 110A may then continue sending further GTP echo request messages to SGW 140 A to determine the reachability status of SGW 140 A as well as other SGWs 140 that belong to the same subnetwork as SGW 140A (e.g., the other SGWs 140 that responded with a GTP echo response message that included a peer subnetwork information element 185) without sending GTP echo request messages to the other SGWs 140.

[0049] By way of another example, referring to Figure 1, radio node HOB may send a GTP echo request message including a peer subnetwork information element 185 to each of the UPFs 145 implemented in datacenter 120B to which radio node HOB has a GTP path (e.g., via the router 170 included in the transport network 160 and switch 150B included in datacenter 120B). In this example, radio node 110A is the GTP initiator and the UPFs 145 are the GTP responders. A UPF 145 that receives the GTP echo request message may determine its own IP address and subnet mask. The UPF 145 may then send a GTP echo response message that includes a peer subnetwork information element 185 to radio node 110B (as a response to the GTP echo request message sent by radio node 110B) (e.g., via switch 150B and the router 170), where the peer subnetwork information element 185 includes an indication of the IP address and subnet mask of the UPF 145. Subsequently, the radio node 110B may determine which of the UPFs 145 responded with a GTP echo response message that included a peer subnetwork information element 185. The radio node 110B may store information regarding those UPFs 145 (e.g., information indicated in the peer subnetwork information elements 185 included in the GTP echo response messages sent by those UPFs 145 (e.g., IP address and subnet mask information)) in a repository. Radio node 110B may then select one of the UPFs 145 that responded with a GTP echo response message that included a peer subnetwork information element 185 to be the representative GTP responder. In this example, radio node 110B selects UPF 145 A to be the representative GTP responder. Radio node 110B may then continue sending further GTP echo request messages to UPF 145 A to determine the reachability status UPF 145A as well as other UPFs 145 that belong to the same subnetwork as UPF 145 A (e.g., the other UPFs 145 that responded with a GTP echo response message that included a peer subnetwork information element 185) without sending GTP echo request messages to the other UPFs 145.

[0050] By selecting a representative GTP responder and sending GTP echo request messages only to the representative GTP responder, embodiments avoid having to actively manage multiple GTP paths. This helps reduce the amount of packet processing load and/or CPU usage of the GTP initiator and the GTP responders. Also, this helps reduce bandwidth consumption in the transport network 160 and/or the datacenters 120 by reducing the number of path management messages (e.g., echo request messages and echo response messages) that are sent. Also, troubleshooting can be simplified when a problem occurs.

[0051] The GTP initiator may select the representative GTP responder using the information provided by the GTP responders in the peer subnetwork information element 185. It should be noted that the GTP responders do not need to know whether they are a representative GTP responder or not - they just respond to any GTP echo request messages sent by the GTP initiator and provide any additional information requested by the GTP initiator. This means that the GTP responders do not need to take any separate action to change the representative GTP responder. [0052] In an embodiment, if the core of the mobile network is scaled up to add more GTP responders belonging to the same subnetwork (e.g., more core network nodes such as SGWs 140 and/or UPFs 145), the GTP initiator keeps the representative GTP responder unchanged. In an embodiment, if the core of the mobile network is scaled up such that there is a change in the IP address configuration, the GTP initiator restarts the process to select a new representative GTP responder.

[0053] In an embodiment, a GTP initiator may select more than one representative GTP responder. The GTP initiator may determine the reachability status of GTP responders belonging to the same subnetwork based on GTP path messages exchanged with one or multiple representative GTP responders.

[0054] Figure 2 is a diagram showing component interactions for providing efficient GTP path management, according to some embodiments.

[0055] This diagram shows an example of GTP path management of GTP paths between a radio node 110 and SGWs 140A-X that belong to the same subnetwork.

[0056] As shown in the diagram, the radio node 110 sends a GTP request message that includes a peer subnetwork information element to each of the SGWs 140A-X that belong to the same subnetwork. Each of the SGWs 140A-X that successfully receives the GTP request message from the radio node 110 responds to the GTP echo request message by sending a corresponding GTP echo response message that includes a peer subnetwork information element to the radio node 110.

[0057] The radio node 110 stores GTP responder information indicated in the peer subnetwork information elements included in the respective GTP echo response messages (e.g., IP address and subnet mask) in a repository.

[0058] The radio node 110 then selects one of the SGWs 140A-X to be a representative GTP responder. In this example, the radio node 110 selects SGW 140B to be the representative GTP responder.

[0059] The radio node 110 continues to send GTP echo request messages to SGW 140B (since it was selected to be the representative GTP responder) but stops sending any further GTP echo request messages to the other SGWs 140. The radio node 110 may determine the reachability status of all of the SGWs 140A-X belonging to the same subnetwork based on the GTP path management messages exchanged with SGW 140B (the representative GTP responder) without sending further GTP echo request message to the other GTP responders.

[0060] If SGW 140B subsequently determines that its IP address and/or subnet mask has changed (e.g., due to a manual update or reconfiguration), SGW 140B may indicate this in a GTP echo response message that it sends to the radio node 110 (e.g., in the peer subnetwork information element included in the GTP echo response message) so that the radio node 110 can be aware of the change. In response, the radio node 110 may restart the process (e.g., send GTP echo request messages to all SGWs 140 belonging to the same subnetwork) to select a new representative GTP responder.

[0061] Figure 3 is a diagram showing formats of a GTP echo request message and a GTP echo response message, according to some embodiments. In an embodiment, as shown in the diagram, the format of an GTP echo request message 310 includes a private extension information element that is optional and a peer subnetwork information element that is optional. Also, in an embodiment, as shown in the diagram, the format of a GTP echo response message 320 includes a recovery information element that is mandatory (e.g., for backwards compatibility reasons), a private extension information element that is optional (e.g., to indicate vendor or operator specific information), and a peer subnetwork information element that is optional.

[0062] As shown in the diagram, the peer subnetwork information element 330 may include a type field (to indicate the peer subnetwork type), a length field (to indicate the length of the information element 330), and a message type field to indicate whether the message type is echo request or echo response. If the message type is echo response, then the peer subnetwork information element 330 may further include an IP address (IPv4 or IPv6 address) field to indicate the IP address of the GTP responder, a subnet mask field to indicate the subnet mask of the GTP responder, a preferred IP address field (optional) to indicate the IP address of the preferred GTP responder, and an operational state field (optional) to indicate the operational state of the GTP responder. In an embodiment, the peer subnetwork information element 330 includes a reserved field (e.g., that is reserved for future extensions/usage). In an embodiment, the peer subnetwork information element 330 includes a field (e.g., as a subfield in the reserved field) to indicate an ID associated with the GTP responder (e.g., a UUID).

[0063] Figure 4 is a diagram showing components of a GTP initiator, according to some embodiments. In an embodiment, as shown in the diagram, the GTP initiator 400 includes a GTP echo receiver 405, a GTP echo sender 410, a peer subnetwork information element handler 415, a repository for GTP peers information 420, a GTP peer status manager 425, and a GTP path manager 430.

[0064] The GTP path manager 430 may determine whether a peer subnetwork information element is to be included in a GTP echo request message that is to be sent to a GTP responder 450. If the GTP path manager 430 determines that a peer subnetwork information element is to be included in the GTP echo request message, then it may invoke the peer subnetwork information element handler 415 to include the peer subnetwork information element in the GTP echo request message. The GTP echo sender 410 may then send the GTP echo request message including the peer subnetwork information element to the GTP responder 450.

[0065] The GTP echo receiver 405 may receive a GTP echo response message from the GTP responder 450. The GTP echo receiver 405 may invoke the peer subnetwork information element handler 415 to determine whether a peer subnetwork information element is included in the GTP echo response message. If the peer subnetwork information element handler 415 determines that a peer subnetwork information element is included in the GTP echo response message, then the GTP initiator 400 may store the information indicated in the peer subnetwork information element (and possibly other information regarding the GTP responder) in the repository for GTP peers information 420. The GTP peer status manager 425 may maintain the reachability status of the GTP responder 450. If the GTP initiator 400 has selected a representative GTP responder, then the GTP echo sender 410 sends GTP echo request messages to the representative GTP responder (but not to other GTP responders that belong to the same subnetwork that were not selected to be representative GTP responders), and the GTP peer status manager 425 maintains the reachability status of the GTP responders belonging to the same subnetwork based on the path management messages exchanged with the representative GTP responder. [0066] Figure 5 is a diagram showing components of a GTP responder, according to some embodiments. In an embodiment, as shown in the diagram, the GTP responder 450 includes a GTP echo receiver 505, a GTP echo sender 510, a peer subnetwork information element handler 515, and a repository for IP information 520.

[0067] The GTP echo receiver 505 may receive a GTP echo request message including a peer subnetwork information element from a GTP initiator 400. The GTP echo receiver 505 may invoke the peer subnetwork information element handler 515 to determine whether the GTP echo request message includes a peer subnetwork information element. If the GTP echo request message includes a peer subnetwork information element, the GTP responder 450 may determine the IP address and subnet mask of the GTP responder 450 based on accessing the repository for IP information 520. In an embodiment, the GTP responder 450 also determines other information such as the preferred IP address and operational state of the GTP responder 450. The GTP echo sender 510 may invoke the peer subnetwork information element handler 515 to include a peer subnetwork information element in the GTP echo response message that is to be sent to the GTP initiator 400. The peer subnetwork information element handler 515 may include an indication of the IP address and subnet mask of the GTP initiator 400 (as well as other information such as the preferred IP address and/or operational state) in the peer subnetwork information element. The GTP echo sender 510 may send the GTP echo response message including the peer subnetwork information element to the GTP initiator as a response to the GTP echo request message.

[0068] Figure 6 is a flow diagram of a method performed by a GTP initiator for determining a reachability status of GTP responders that belong to the same subnetwork, according to some embodiments. The method may be implemented using hardware, software, or a combination thereof (e.g., by a network device implementing the GTP initiator).

[0069] The operations in the flow diagrams will be described with reference to the exemplary embodiments of the other figures. However, it should be understood that the operations of the flow diagrams can be performed by embodiments of the invention other than those discussed with reference to the other figures, and the embodiments of the invention discussed with reference to these other figures can perform operations different than those discussed with reference to the flow diagrams.

[0070] At operation 610, the GTP initiator sends a GTP echo request message that includes a peer subnetwork information element to each of a plurality of GTP responders. In an embodiment, the GTP initiator is a radio node of a mobile network and the plurality of GTP responders are core network nodes of the mobile network. In an embodiment, the plurality of GTP responders are serving gateways of the mobile network or user plane functions of the mobile network.

[0071] At operation 620, responsive to receiving a GTP echo response message including a peer subnetwork information element from at least two of the plurality of GTP responders, the GTP initiator selects one of the at least two GTP responders to be a representative GTP responder. In an embodiment, the peer subnetwork information element included in the GTP echo response message received from a GTP responder includes an indication of an IP address of the GTP responder and a subnet mask of the GTP responder. In an embodiment, the GTP initiator stores information regarding the at least two GTP responders indicated in the peer subnetwork information elements (e.g., the IP address and subnet mask of those GTP responders) in a repository. In an embodiment, the peer subnetwork information element included in the GTP echo response message received from a GTP responder includes an indication of a preferred internet protocol (IP) address, wherein the preferred IP address is an IP address of one of the plurality of GTP responders that is designated as being a preferred representative GTP responder. In an embodiment, the GTP responder having the preferred IP address is selected to be the representative GTP responder.

[0072] At operation 630, the GTP initiator continues to send further GTP echo request messages to the representative GTP responder to determine the reachability status of the at least two GTP responders without sending GTP echo request messages to others of the at least two GTP responders that were not selected to be a representative GTP responder. In an embodiment, the GTP initiator receives a GTP echo response message that includes a peer subnetwork information element from the representative GTP responder as a response to one of the further GTP echo request messages sent to the representative GTP responder. This may indicate to the GTP initiator that all of the at least two GTP responders are reachable.

[0073] In an embodiment, at operation 640, the GTP initiator determines whether any relevant information regarding the representative GTP responder (e.g., the IP address of the representative GTP responder, the subnet mask of the representative GTP responder, the preferred IP address indicated by the GTP responder, and/or the operational state of the GTP responder) has changed. If not, the GTP initiator continues to send further GTP echo request messages to the representative GTP responder. Otherwise, if the GTP initiator determines that relevant information regarding the representative GTP responder has changed, then the method may return to operation 610, where the GTP initiator sends a GTP echo request message to each of the plurality of GTP responders (e.g., to potentially select a new representative GTP responder). [0074] Figure 7 is a flow diagram of a method performed by a GTP responder, according to some embodiments. The method may be implemented using hardware, software, or a combination thereof (e.g., by a network device implementing the GTP responder).

[0075] At operation 710, the GTP responder receives a GTP echo request message from a GTP initiator. In an embodiment, the GTP initiator is a radio node of a mobile network and the GTP responder is a core network node of the mobile network. In an embodiment, the GTP responder is a serving gateway of the mobile network or a user plane function of the mobile network.

[0076] At operation 720, the GTP responder determines whether the GTP echo request message includes a peer subnetwork information element. If not, at operation 730, the GTP responder sends a legacy GTP echo response message (that does not include a peer subnetwork information element) to the GTP initiator. Otherwise, if the GTP responder determines that the GTP echo request message includes a peer subnetwork information element, at operation 740, the GTP responder may determine its own IP address and subnet mask.

[0077] At operation 750, the GTP responder sends a GTP echo response message that includes a peer subnetwork information element to the GTP initiator. The peer subnetwork information element included in this GTP echo response message may indicate the IP address and subnet mask of the GTP responder (e.g., which were determined at operation 740). In an embodiment, the peer subnetwork information element included in the GTP echo response message includes an indication of a preferred IP address, wherein the preferred IP address is an IP address of one of the plurality of GTP responders that is designated as being a preferred representative GTP responder. In an embodiment, the peer subnetwork information element included in the GTP echo response message includes an indication of an operation state of the GTP responder. In an embodiment, the peer subnetwork information element included in the GTP echo response message includes an indication of an ID associated with the GTP responder.

[0078] The method may then return to operation 710, where the GTP responder waits to receive another GTP echo request message from a GTP initiator.

[0079] Figure 8 is a diagram showing an example of a communication system 800 in accordance with some embodiments.

[0080] In the example, the communication system 800 includes a telecommunication network 802 that includes an access network 804, such as a radio access network (RAN), and a core network 806, which includes one or more core network nodes 808 (e.g., SGWs 140 or UPFs 145). The access network 804 includes one or more access network nodes, such as network nodes 810a and 810b (one or more of which may be generally referred to as network nodes 810) (e.g., radio nodes 110), or any other similar 3^rd Generation Partnership Project (3 GPP) access node or non-3GPP access point. The network nodes 810 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 812a, 812b, 812c, and 812d (one or more of which may be generally referred to as UEs 812) to the core network 806 over one or more wireless connections.

[0081] Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 800 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 800 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

[0082] The UEs 812 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 810 and other communication devices. Similarly, the network nodes 810 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 812 and/or with other network nodes or equipment in the telecommunication network 802 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 802.

[0083] In the depicted example, the core network 806 connects the network nodes 810 to one or more hosts, such as host 816. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 806 includes one more core network nodes (e.g., core network node 808) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 808. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

[0084] The host 816 may be under the ownership or control of a service provider other than an operator or provider of the access network 804 and/or the telecommunication network 802, and may be operated by the service provider or on behalf of the service provider. The host 816 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0085] As a whole, the communication system 800 of Figure 8 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0086] In some examples, the telecommunication network 802 is a cellular network that implements 3 GPP standardized features. Accordingly, the telecommunications network 802 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 802. For example, the telecommunications network 802 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.

[0087] In some examples, the UEs 812 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 804 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 804. Additionally, a UE may be configured for operating in single- or multi-RAT or multi -standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0088] In the example, the hub 814 communicates with the access network 804 to facilitate indirect communication between one or more UEs (e.g., UE 812c and/or 812d) and network nodes (e.g., network node 810b). In some examples, the hub 814 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 814 may be a broadband router enabling access to the core network 806 for the UEs. As another example, the hub 814 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 810, or by executable code, script, process, or other instructions in the hub 814. As another example, the hub 814 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 814 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 814 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 814 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 814 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

[0089] The hub 814 may have a constant/persistent or intermittent connection to the network node 810b. The hub 814 may also allow for a different communication scheme and/or schedule between the hub 814 and UEs (e.g., UE 812c and/or 812d), and between the hub 814 and the core network 806. In other examples, the hub 814 is connected to the core network 806 and/or one or more UEs via a wired connection. Moreover, the hub 814 may be configured to connect to an M2M service provider over the access network 804 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 810 while still connected via the hub 814 via a wired or wireless connection. In some embodiments, the hub 814 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 810b. In other embodiments, the hub 814 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 810b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

[0090] Figure 9 is a diagram showing a network node 900 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). [0091] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0092] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi -standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

[0093] The network node 900 includes a processing circuitry 902, a memory 904, a communication interface 906, and a power source 908. The network node 900 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 900 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 900 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 904 for different RATs) and some components may be reused (e.g., a same antenna 910 may be shared by different RATs). The network node 900 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 900, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 900.

[0094] The processing circuitry 902 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 900 components, such as the memory 904, to provide network node 900 functionality.

[0095] In some embodiments, the processing circuitry 902 includes a system on a chip (SOC). In some embodiments, the processing circuitry 902 includes one or more of radio frequency (RF) transceiver circuitry 912 and baseband processing circuitry 914. In some embodiments, the radio frequency (RF) transceiver circuitry 912 and the baseband processing circuitry 914 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 912 and baseband processing circuitry 914 may be on the same chip or set of chips, boards, or units.

[0096] The memory 904 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 902. The memory 904 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 902 and utilized by the network node 900 (e.g., memory 904 may store instructions that when executed by the processing circuitry 902 causes the network node 900 to perform operations for performing efficient GTP path management, as described herein). The memory 904 may be used to store any calculations made by the processing circuitry 902 and/or any data received via the communication interface 906. In some embodiments, the processing circuitry 902 and memory 904 is integrated.

[0097] The communication interface 906 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, the communication interface 906 comprises port(s)/terminal(s) 916 to send and receive data, for example to and from a network over a wired connection. The communication interface 906 also includes radio front-end circuitry 918 that may be coupled to, or in certain embodiments a part of, the antenna 910. Radio front-end circuitry 918 comprises filters 920 and amplifiers 922. The radio front-end circuitry 918 may be connected to an antenna 910 and processing circuitry 902. The radio front-end circuitry may be configured to condition signals communicated between antenna 910 and processing circuitry 902. The radio front-end circuitry 918 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 918 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 920 and/or amplifiers 922. The radio signal may then be transmitted via the antenna 910. Similarly, when receiving data, the antenna 910 may collect radio signals which are then converted into digital data by the radio front-end circuitry 918. The digital data may be passed to the processing circuitry 902. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

[0098] In certain alternative embodiments, the network node 900 does not include separate radio front-end circuitry 918, instead, the processing circuitry 902 includes radio front-end circuitry and is connected to the antenna 910. Similarly, in some embodiments, all or some of the RF transceiver circuitry 912 is part of the communication interface 906. In still other embodiments, the communication interface 906 includes one or more ports or terminals 916, the radio front-end circuitry 918, and the RF transceiver circuitry 912, as part of a radio unit (not shown), and the communication interface 906 communicates with the baseband processing circuitry 914, which is part of a digital unit (not shown).

[0099] The antenna 910 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 910 may be coupled to the radio front-end circuitry 918 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 910 is separate from the network node 900 and connectable to the network node 900 through an interface or port.

[00100] The antenna 910, communication interface 906, and/or the processing circuitry 902 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, the antenna 910, the communication interface 906, and/or the processing circuitry 902 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

[00101] The power source 908 provides power to the various components of network node 900 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 908 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 900 with power for performing the functionality described herein. For example, the network node 900 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 908. As a further example, the power source 908 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[00102] Embodiments of the network node 900 may include additional components beyond those shown in Figure 9 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 900 may include user interface equipment to allow input of information into the network node 900 and to allow output of information from the network node 900. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 900.

[00103] Figure 10 is a diagram showing a virtualization environment 1000 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein (e.g., for performing efficient GTP path management) may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1000 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized.

[00104] Applications 1002 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

[00105] Hardware 1004 includes processing circuitry, memory that stores software and/or instructions executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1006 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1008a and 1008b (one or more of which may be generally referred to as VMs 1008), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. The virtualization layer 1006 may present a virtual operating platform that appears like networking hardware to the VMs 1008.

[00106] The VMs 1008 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1006. Different embodiments of the instance of a virtual appliance 1002 may be implemented on one or more of VMs 1008, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[00107] In the context of NFV, a VM 1008 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1008, and that part of hardware 1004 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1008 on top of the hardware 1004 and corresponds to the application 1002.

[00108] Hardware 1004 may be implemented in a standalone network node with generic or specific components. Hardware 1004 may implement some functions via virtualization. Alternatively, hardware 1004 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1010, which, among others, oversees lifecycle management of applications 1002. In some embodiments, hardware 1004 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1012 which may alternatively be used for communication between hardware nodes and radio units.

[00109] Although the computing devices described herein (e.g., UEs, network nodes, hosts) 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.

[00110] 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.

[00111] While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described, can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting.

Claims

CLAIMS What is claimed is:

1. A method performed by a general packet radio service tunneling protocol (GTP) initiator to determine a reachability status of GTP responders that belong to a same subnetwork, comprising: sending (610) a GTP echo request message that includes a peer subnetwork information element to each of a plurality of GTP responders; responsive to receiving a GTP echo response message including a peer subnetwork information element from at least two of the plurality of GTP responders, selecting (620) one of the at least two GTP responders to be a representative GTP responder; and sending (630) further GTP echo request messages to the representative GTP responder to determine the reachability status of the at least two GTP responders without sending GTP echo request messages to others of the at least two GTP responders that were not selected to be a representative GTP responder.

2. The method of claim 1, wherein the peer subnetwork information element included in the GTP echo response message received from a GTP responder includes an indication of an internet protocol (IP) address of the GTP responder and a subnet mask of the GTP responder.

3. The method of claim 2, storing information regarding the IP address of the GTP responder and the subnet mask of the GTP responder in a repository.

4. The method of any one of claims 1, wherein the peer subnetwork information element included in the GTP echo response message received from a GTP responder includes an indication of a preferred internet protocol (IP) address, wherein the preferred IP address is an IP address of one of the plurality of GTP responders that is designated as being a preferred representative GTP responder.

5. The method of claim 4, wherein the GTP responder having the preferred IP address is selected to be the representative GTP responder.

6. The method of claim 1, further comprising: receiving a GTP echo response message that includes a peer subnetwork information element from the representative GTP responder as a response to one of the further GTP echo request messages sent to the representative GTP responder.

7. The method of claim 6, further comprising: determining, based on the peer subnetwork information element included in the GTP echo response message received from the representative GTP responder, whether information regarding the representative GTP responder has changed; and responsive to a determination that the information regarding the representative GTP responder has changed, sending a GTP echo request message to each of the plurality of GTP responders.

8. The method of claim 1, wherein the GTP initiator is a radio node of a mobile network and the plurality of GTP responders are core network nodes of the mobile network.

9. The method of claim 8, wherein the plurality of GTP responders are serving gateways of the mobile network or user plane functions of the mobile network.

10. A method performed by a general packet radio service tunneling protocol (GTP) responder from a plurality of GTP responders belonging to a same subnetwork, the method comprising: receiving (710) a GTP echo request message from a GTP initiator; and responsive to a determination (720) that the GTP echo request message includes a peer subnetwork information element, sending (750) a GTP echo response message that includes a peer subnetwork information element to the GTP initiator.

11. The method of claim 10, wherein the peer subnetwork information element included in the GTP echo response message includes an indication of an internet protocol (IP) address of the GTP responder and a subnet mask of the GTP responder.

12. The method of claim 10, wherein the peer subnetwork information element included in the GTP echo response message includes an indication of a preferred internet protocol (IP) address, wherein the preferred IP address is an IP address of one of the plurality of GTP responders that is designated as being a preferred representative GTP responder.

13. The method of claim 10, wherein the peer subnetwork information element included in the GTP echo response message includes an indication of an operational state of the GTP responder.

14. The method of claim 10, wherein the peer subnetwork information element included in the GTP echo response message includes an indication of an identifier (ID) associated with the GTP responder.

15. The method of claim 10, wherein the GTP initiator is a radio node of a mobile network and the GTP responder is a core network node of the mobile network.

16. The method of claim 15, wherein the GTP responder is a serving gateway of the mobile network or a user plane function of the mobile network.

17. A non-transitory machine-readable storage medium that provides instructions that, if executed by a processor of a network device implementing a GTP initiator, causes the GTP initiator to carry out the method of any one of claims 1-9.

18. A non-transitory machine-readable storage medium that provides instructions that, if executed by a processor of a network device implementing a GTP responder, causes the GTP responder to carry out the method of any one of claims 10-16.