KR102768614B1 - Method and system of processing data packet for providing low latency roaming edge service - Google Patents

Abstract

A method for processing a data packet for providing a low-latency edge roaming service and a system thereof are provided. The system is a method for processing a roaming data packet in an edge roaming switch located in a visited network, comprising: a step of receiving a roaming data packet transmitted by a roaming terminal from a data gateway of the visited network; a step of determining whether a destination IP address of the roaming data packet is an edge service target registered in a pre-stored edge forwarding table; a step of offloading the roaming data packet to an edge service network of the visited network if it is determined to be an edge service target; and a step of transmitting the roaming data packet to a data gateway of a home network if it is determined not to be an edge service target.

Description

METHOD AND SYSTEM OF PROCESSING DATA PACKET FOR PROVIDING LOW LATENCY ROAMING EDGE SERVICE

The present invention relates to a method for processing data packets for providing a low-latency edge roaming service and a system therefor.

When a mobile subscriber roams overseas, in order to receive data services on an LTE (Long-Term Evolution) wireless network, the subscriber must access the PDN (Packet Data Network) gateway (hereinafter, collectively referred to as 'P-GW') of the home network (Home Public Land Mobile Network, HPMN) from the Serving Gateway (hereinafter, collectively referred to as 'S-GW') of the Visited Public Land Mobile Network (VPMN). In other words, roaming data packets are transmitted through the GTP (GPRS Tunneling Protocol) tunnel created between the Visited Network S-GW and the Home Network P-GW.

However, the method of transmitting all roaming data packets from the visiting network to the home network, i.e., the international network, causes network delays due to physical distance. In addition, there is a limitation in not being able to provide a low-price policy to roaming users because the expensive international network is used.

In addition, this method of processing roaming data packets is structurally incapable of optimally utilizing the global CDN (content delivery network or content distribution network) utilized by most Internet service providers based on user location, making it difficult to improve service quality compared to a wired environment.

The 3rd Generation Partnership Project (3GPP) presented an improved roaming data packet processing structure as part of the standardization work for the 5G SA (standalone) architecture. According to this structure, roaming traffic is routed to the PDN (Packet Data Network) within the visited network through an interface connection between the main equipment that manages subscriber authentication and charging policy data of the home network operator and the visited network operator, that is, the Authentication Server Function (AUSF) and the User Data Management (UDM).

However, this method requires modification of the existing EPC (Evolved Packet Core). In addition, since home network operators and visiting network operators must share subscriber information, there are security concerns and problems that prevent it from being applied to the roaming system.

The problem to be solved by the present invention is to provide a method and system for providing a low-latency edge roaming service by performing local breakout (LBO) that offloads roaming data packets of a terminal roaming from a home network to a visited network to an edge service network constructed in the visited network.

According to one feature of the present invention, a method for processing a roaming data packet is a method for processing a roaming data packet in an edge roaming switch located in a visited network, comprising the steps of: receiving a roaming data packet transmitted by a roaming terminal from a data gateway of the visited network; determining whether a destination IP address of the roaming data packet is an edge service target registered in a pre-stored edge forwarding table; if determined to be an edge service target, offloading the roaming data packet to an edge service network of the visited network; and if determined not to be an edge service target, transmitting the roaming data packet to a data gateway of a home network.

Before the receiving step, the method may further include performing mutual authentication with an edge roaming controller located in the visited network and connected to the edge roaming switch, and then receiving the edge forwarding table from the edge roaming controller.

The above edge roaming switch and the edge roaming controller can verify and update the validity of the edge forwarding table by interworking based on a predefined communication protocol.

The above edge roaming switch and the edge roaming controller can verify and update the validity of the edge forwarding table using an HTTP (HyperText Transfer Protocol) method.

The above receiving step receives a tunneling roaming data packet including a tunneling header through a tunneling section formed with the data gateway of the above-mentioned visiting network,

The above judgment step determines whether the destination IP address confirmed from the IP header of the inner packet within the tunneling roaming data packet is the target of the edge service.

The above offloading step offloads the restored IP packet by removing the tunneling header from the tunneling roaming data packet,

The step of transmitting to the data gateway of the above home network can transmit a tunneling roaming data packet received through the above tunneling section.

After the above offloading step, the method further includes the steps of receiving an IP packet from the edge service network, adding a tunneling header to the IP packet to convert it into a tunneling roaming data packet, and transmitting the tunneling roaming data packet to a data gateway of the visited network, wherein the tunneling roaming data packet is transmitted from the data gateway of the visited network to a base station, and is restored to an original data packet with the tunneling header removed by the base station and transmitted to the roaming terminal.

The above edge roaming switch is connected to the visiting network data gateway and the home network data gateway respectively through the first interface,

The above first interface may be defined as an interface connecting the visit network data gateway and the home network data gateway.

The above edge roaming switch is connected to the edge service node through a second interface using an IP packet forwarding protocol that defines the user plane,

The above edge service node can be connected to the Internet network.

According to another feature of the present invention, an edge roaming system includes an edge roaming controller which manages an edge forwarding table which stores information on an edge service target, and an edge roaming switch which receives and stores the edge forwarding table from the edge roaming controller, is located between a visited network data gateway and a home network data gateway, receives uplink roaming data from a roaming terminal located in the visited network through the visited network data gateway, determines whether the uplink roaming data is an edge service target based on the edge forwarding table, and, if determined to be an edge service target, performs a local breakout routing of the uplink roaming data to an edge service node.

The above edge forwarding table can be dynamically updated according to changes in the edge service node.

The above edge roaming controller and the above edge roaming switch, if mutual authentication is successful, can verify the validity of the edge forwarding table and then proceed with an update.

The above edge roaming switch can route the uplink roaming data to the home network data gateway if the destination of the uplink roaming data is not registered in the edge forwarding table.

The above edge roaming switch can communicate with the visited network data gateway and the home network data gateway using a tunneling protocol, and route uplink roaming data in the form of tunneling data received from the visited network data gateway to the home network data gateway.

The above edge roaming switch can remove a tunneling header from uplink roaming data in the form of tunneling data received from the visited network data gateway, restore it to an IP packet, and offload the uplink roaming data in the form of an IP packet to the edge service network.

The above edge roaming switch can add a tunneling header to downlink roaming data in the form of IP packets received from the edge service node and transmit it to the visited network data gateway.

The above edge roaming switch can store tunneling information matching the IP address of the roaming terminal and add the tunneling header using the tunneling information matching the source IP address included in the downlink roaming data as a flag.

The edge roaming system further includes a local DNS located in the home network and performing a DNS (Domain Name System) query for an IP address of a domain name requested by the roaming terminal in response to a request from the roaming terminal, and a GSLB (Global Server Load Balancing) server located in the home network and providing an IP address according to the DNS query received from the local DNS.

The above GSLB server can store the IP address of the edge service node by mapping it to the domain name of a service that is locally breakout routed to the edge service network.

According to an embodiment, an edge switch (eSW) is installed at the back end of an S-GW of a visited network, and by offloading specific roaming data packets to an edge service network of the visited network rather than a P-GW of the home network, the network transmission delay time is reduced.

In addition, since traffic is processed in an edge service network that is physically close to customers, it is possible to reduce the cost of using international networks when transmitting large amounts of content, thereby providing a stable Internet service.

Additionally, as in the 3GPP standard, mobile operators can process all roaming data packets within the visited network without connecting the interfaces of main equipment or modifying the deployed Evolved Packet Core (EPC) equipment.

Additionally, the path of roaming data packets can be processed within the visited network for each edge application/service, so that user traffic requests can be processed through the edge CDN (content delivery network or content distribution network) built in the visited country.

FIG. 1 is a configuration diagram of a low-latency edge roaming system according to an embodiment of the present invention.
FIG. 2 illustrates a transmission process of an uplink roaming data packet according to an embodiment of the present invention.
FIG. 3 illustrates a transmission process of a downlink roaming data packet according to an embodiment of the present invention.
FIG. 4 is a flowchart illustrating a DNS query operation of a roaming terminal according to an embodiment of the present invention.
FIG. 5 is a flowchart illustrating a registration process of a data packet rule for a low-latency edge roaming service according to an embodiment of the present invention.
FIG. 6 is a flowchart illustrating a series of procedures for providing a low-latency edge roaming service according to an embodiment of the present invention.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are assigned similar drawing reference numerals throughout the specification.

Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

Additionally, terms such as “part,” “unit,” and “module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware, software, or a combination of hardware and software.

As used herein, “transmitting or providing” may include not only direct transmission or providing, but also indirect transmission or providing via another device or by using a bypass route.

In this specification, expressions described in the singular may be interpreted as singular or plural, unless explicit expressions such as “one” or “singular” are used.

In this specification, a terminal is a comprehensive concept meaning a user terminal in communication, and may refer to a client, a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment (UE), an access terminal (AT), etc., and may include all or part of the functions of a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, etc.

The terminal can be connected to a remote server by accessing network devices such as a gateway, base station (BS), access point (AP), radio access station (RAS), node B, evolved NodeB (eNodeB), base transceiver station (BTS), mobile multihop relay (MMR)-BS, 5G NB (gNB), etc.

The terminal of this specification may be a mobile terminal such as a smart phone, a tablet terminal such as a smart pad and a tablet PC, a computer, a television, or other various types of communication terminals, and may be equipped with multiple communication interfaces.

A base station (BS) may refer to an Access Point (AP), a Radio Access Station (RAS), a Node B, a Base Transceiver Station (BTS), a Mobile Multihop Relay (MMR)-BS, etc., and may include all or part of the functions of an Access Point, a Radio Access Station, a Node B, a Base Transceiver Station, and an MMR-BS. Here, the BS may include a Node B of the 3G standard, an eNB (eNode B) of the 4G LTE (Long Term Evolution) standard, an En-Gnb used in the 5G NSA (Non Standalone) standard, and a gNB used in the 5G SA (Standalone) standard. The En-gNB is defined as a new base station that supports 5G New Radio technology and interworking with 5G Core, while simultaneously interworking with Evolved Packet Core (EPC) and eNodeB.

Embodiments of the present invention can be supported by standard documents related to 3GPP (3rd Generation Partnership Project) system, 3GPP LTE (Long Term Evolution) and LTE-A system, and 3GPP 5G system such as Study on Architecture for Next Generation System (FS_NextGen), which establish technical specifications of 3rd generation mobile communication system. That is, steps or parts that are not described in order to clearly reveal the technical idea of the present invention among the embodiments of the present invention can be supported by the above documents. In addition, all terms disclosed in this document can be explained by the above standard documents. In this specification, roaming refers to a service that enables communication connection even in the service areas of different communication service providers, and overseas roaming refers to a service that connects communication between communication service providers in different countries.

Edge services are provided at or near the physical location of the customer or data source.

A content delivery network (CDN) is a network of servers strategically distributed around the world.

Now, with reference to the drawings, a method and system for processing data packets for providing a low-latency edge roaming service according to an embodiment of the present invention will be described.

FIG. 1 is a configuration diagram of a low-latency edge roaming system according to one embodiment of the present invention. At this time, for convenience of explanation, only the configuration related to processing of data packets for the low-latency edge roaming service of the present invention is shown.

Referring to FIG. 1, the low-latency edge roaming system includes a roaming terminal (100), a visited public land mobile network (VPLMN) (200), and a home public land mobile network (HPLMN) (300).

A roaming terminal (100) refers to a terminal located in a visited network (200) outside the home network (300). A roaming terminal (100) accesses a visited network (200), not a home network (300), from overseas to use a roaming (outbound roaming) service.

The visited network (200) includes a base station (eNB/en-gNB) (201), a visited network S-GW (203), an edge roaming switch (205), an edge service node (207), and a visited network edge roaming controller (209).

The home network (300) includes a home network P-GW (301), NAT (Network Address Translation) (303), a home network-edge roaming controller (305), a local DNS (Domain Name Server) (307), and GSLB (Global Server Load Balancing) (309).

The base station (201) is a base station located in the visited network (200) and is connected to a roaming terminal (100). The base station (201) provides wireless access to the roaming terminal (100) using RAT (Radio Access Technology) and connects the roaming terminal (100) and the core equipment (S-GW) (203). The RAT may use technologies such as LTE and 5G.

In the embodiment of Fig. 1, the base station (201) may be an eNB and/or an en-gNB, and the visited network (200) and the home network (300) correspond to an LTE or 5G NSA structure. In this structure, the visited network S-GW (203) and the home network P-GW (301) are connected through GTP (GPRS Tunneling Protocol) tunneling.

In addition, according to another embodiment, the base station (201) may be a gNB, in which case the visited network (200) and the home network (300) correspond to a 5G SA structure. In this structure, a visited network UPF (User Plane Function) is positioned instead of the visited network S-GW (203), and a home network UPF is positioned instead of the home network P-GW (301). In addition, the visited network UPF and the home network UPF are connected through GTP tunneling.

In this specification, the visited network S-GW (203), the home network P-GW (301), the visited network UPF, and the home network UPF are gateways that process user data, and may be referred to as data gateways in other terms. Hereinafter, for the convenience of explanation, the LTE or 5G NSA structure is described as an example in this specification, but the edge roaming procedure is equally applicable to the 5G SA structure.

The visiting network S-GW (203) is connected to the base station (201) through an S1-U interface and to the edge roaming switch (205) through an S8 interface.

The visiting network S-GW (203) forwards the roaming data packet received from the base station (201) to the edge roaming switch (205).

In the conventional roaming service, the visited network S-GW (203) unconditionally forwards roaming data packets to the home network P-GW (301). However, in the embodiment of the present invention, a new node called an edge roaming switch (205) is added between the visited network S-GW (203) and the home network P-GW (301). Therefore, the visited network S-GW (203) transmits roaming data packets to the edge roaming switch (205).

The edge roaming switch (205) is connected to the edge service node (207), the visiting network-edge roaming controller (209), and the home network P-GW (301), respectively.

The edge roaming switch (205) is connected to the edge service node (207) via an SGi interface. The edge service node (207) is connected to the Internet network (500) and transmits and receives data packets that are targets of edge roaming. For example, the edge service node (207) may be a CDN node.

The edge roaming switch (205) is connected to the home network P-GW (301) through an interworking network (400) such as IPX (Internetwork Packet Exchange). At this time, the edge roaming switch (205) is connected to the home network P-GW (301) through an S8 interface.

The edge roaming switch (205) is a node for logically coordinating tunneling communication of roaming data packets.

The edge roaming switch (205) is an IP routing node that enables Internet communication within the visiting network by IP routing data packets from a roaming terminal (100).

The edge roaming switch (205) is located at the rear end of the visiting network S-GW (203). The edge roaming switch (205) selects and adjusts the transmission path of roaming data packets.

The targeted service data packet is redirected to the visiting network, and if it is not a targeted service data packet, it is routed to the home network (300). Here, the targeted service data packet refers to an edge service/application data packet.

The edge roaming switch (205) selects an uplink transmission path or a downlink transmission path for roaming data packets and routes the roaming data packets to the selected path.

The edge roaming switch (205) performs local breakout (LBO) by offloading roaming data packets generated from a specific service/application to the edge service node (207) within the visited network instead of transmitting them to the home network P-GW (301). That is, data packets that are the target of edge services requiring processing within the visited network are transmitted via the path of the edge service node (207) -> Internet network (500).

Data packets routed to the edge service node (207) are transmitted to the roaming terminal (100) via the path of edge service node (207)->edge roaming switch (205)->visited network S-GW (203)->base station (201).

Meanwhile, data packets that are general service targets and do not require processing within the home network are transmitted via the path of home network P-GW (301)->NAT (303)->Internet network (500). At this time, NAT (303) performs processing such as NAT conversion required for access to the Internet network (500).

The edge roaming switch (205) has an edge forwarding table in which information about target service data packets is registered. If the destination IP address (Destination Internet Protocol, hereinafter collectively referred to as 'DIP') of the roaming data packet is registered in the edge forwarding table, the edge roaming switch (205) offloads the roaming data packet to the edge service node (207). However, if it is an unregistered DIP, it is routed to the home network P-GW (301).

Here, the edge forwarding table can be updated periodically.

At this time, the offloading target can be dynamically changed through a DNS lookup located in the home network, for example, GSLB (Global Service Load Balancing) (309).

The local DNS (307) is located in the home network (300) and is connected to NAT (303). The local DNS (307) receives a domain name query from a roaming terminal (100).

The local DNS (307) is connected to a GSLB server (309) and, although not shown, is also connected to multiple name servers (root DNS, top level DNS, second level DNS, etc.).

The local DNS (307) stores domain names to be served by the edge. A GSLB server (309) is mapped to these domain names.

When a DNS query for an unregistered domain name is received, the local DNS (307) requests a recursive query to multiple name servers. Then, it obtains an IP address for the queried domain name from one of the multiple name servers. The local DNS (307) provides this IP address to the roaming terminal (100). Then, the roaming terminal (100) uses a general roaming service that does not require processing within the visited network.

When a DNS query for a registered domain name is received, the local DNS (307) forwards the domain name query received from the roaming terminal (100) to the GSLB server (309).

The GSLB server (309) stores the edge service IP corresponding to the domain name, i.e., the IP address of the edge service node. The GSLB server (309) provides the IP address of the edge service node according to the DNS query requested from the local DNS (307) to the local DNS (307). The local DNS (307) transmits the IP address of this edge service node to the roaming terminal (100). Then, the roaming terminal (100) uses the edge roaming service that requires processing within the visited network. The home network-edge roaming controller (305) and the visited network-edge roaming controller (209) connect through a mutual authentication protocol and periodically perform an update process to match the data packet filter rules that are the targets of the edge service. An IP address that is the target of the edge service can be registered in either the home network-edge roaming controller (305) or the visited network-edge roaming controller (209), and when a new data packet filter rule is registered, the home network-edge roaming controller (305) and the visited network-edge roaming controller (209) have a process of checking whether the data packet filter rules are the same and sharing them.

The edge roaming controller (209) is connected to the edge roaming switch (205) and transmits a data packet filter rule to the edge roaming switch (205).

According to one embodiment, the visited network-edge roaming controller (209) and the edge roaming switch (205) may be connected to each other based on the OpenFlow protocol. For example, they may be connected using an m-SDN (Mobile (Software Defined Network) protocol interface. In this case, the edge roaming switch (205) may receive a data packet filter rule from the visited network-edge roaming controller (209) using an OpenFlow message (or SDN message).

In another embodiment, the visiting network-edge roaming controller (209) may be connected to the edge roaming switch (205) via a CLI (Command Line Interface) TCP (Transmission Control Protocol) interface.

According to another embodiment, the edge roaming controller (209) may be connected to the edge roaming switch (205) via a JavaScript Object Notation (JSON) interface.

In addition to the interfaces described above, the visiting network-edge roaming controller (209) can be connected to the edge roaming switch (205) through various data exchange interfaces.

In addition, one visit network-edge roaming controller (209) can be connected to multiple edge roaming switches (205). At this time, multiple edge roaming switches (205) can be connected as many as the number of visit network S-GWs (203) built in the visit network. For example, if the visit network S-GWs (203) are built in a region unit, the edge roaming switches (205) can be connected as many as the number of regions. However, this is merely an example, and various other examples are possible.

Fig. 2 illustrates a transmission process of an uplink roaming data packet according to an embodiment of the present invention. In Fig. 2, a roaming data packet means an uplink packet.

Referring to FIG. 2, a roaming terminal (100) transmits a roaming data packet to a base station (201). At this time, the transmitted roaming data packet has an RLC (Radio Link Control) header and a PDCP (Packet Data Convegence Protocol) header added and is transmitted through a DRB (Data Resource Barear). The source address (Source Internet Protocol, hereinafter collectively referred to as 'SIP') of the roaming data packet is set to the IP address of the roaming terminal (100), and the destination address (Destination Internet Protocol, hereinafter collectively referred to as 'DIP') is set to a service IP address. Here, the service IP address is set to an IP address acquired by the roaming terminal (100) from a local DNS (307).

The base station (201) adds a GTP tunneling header to a roaming data packet received from a roaming terminal (100) and converts it into an S1-GTP tunneling data packet. At this time, the S1-GTP tunneling header includes an IP header, a User Datagram Protocol (UDP) header, and a GTP ID. The SIP of the IP header is set to the base station IP address, and the DIP of the IP header is set to the IP address of the visited network S-GW (203). The GTP ID uses TEID (Tunnel ID) and can be set to '100', for example.

In this way, the converted S1-GTP tunneling data packet is transmitted from the base station (201) to the visited network S-GW (203).

The visited network S-GW (203) removes the GTP header of the S1-GTP tunneling data packet received from the base station (201) and converts it into an S8-GTP tunneling data packet with the GTP tunneling header connected to the home network P-GW (301) added. At this time, the IP header of the S8-GTP tunneling data packet is set to SIP as the IP address of the visited network S-GW (203) and DIP as the IP address of the edge roaming switch (205). In addition, the GTP ID is set differently from the S1-GTP tunneling ID and can be set to '200', for example.

According to one embodiment, the edge roaming switch (205) checks the DIP set in the header of the inner packet in the S8-GTP tunneling data packet received from the visiting network S-GW (203). At this time, various embodiments are possible for the method of checking the header of the inner packet.

The edge roaming switch (205) deletes the GTP header from the S8-GTP tunneling data packet and restores it to an IP packet if the IP address set in the DIP is an IP address registered in the edge forwarding table. Then, the DIP in the restored IP packet is switched to the edge service node IP in the visited network for offloading.

On the other hand, if the IP address set in the DIP is not registered in the edge forwarding table, the S8-GTP tunneling data packet received from the visiting network S-GW (203) is routed as is to the home network P-GW (301).

According to another embodiment, the edge roaming switch (205) removes the GTP tunneling header of the S8-GTP tunneling data packet received from the visited network S-GW (203) and restores it to an IP packet. Then, it checks whether the DIP in the header of the restored IP packet is an IP address registered in the edge forwarding table. If it is a registered IP address, the DIP in the restored IP packet is switched to the IP of the edge service node (207) in the visited network and offloaded. If it is an unregistered IP address, the GTP data packet is created by adding the S8-GTP tunneling header to the restored IP packet and then routing it to the home network P-GW (301).

In this way, only specific roaming data packets of a roaming terminal (100) can be offloaded directly to the edge service node (207) within the visited network without going through the home network through the edge roaming switch (205). As a result, low delay is possible for specific roaming data packets.

FIG. 3 illustrates a transmission process of a downlink roaming data packet according to an embodiment of the present invention. Hereinafter, in the description of FIG. 3, a roaming data packet means a downlink data packet.

Referring to FIG. 3, an edge service node (207) transmits an IP packet in which SIP is set to a service IP (IP address of the edge service node) and DIP is set to an IP address of a roaming terminal (100) to an edge roaming switch (205).

The edge roaming switch (205) has the TEID allocated to each roaming terminal (100) mapped to the IP address of the roaming terminal (100). This TEID is allocated during the session process of the roaming terminal (100), and the edge roaming switch (205) may receive and have it from the core equipment (MME or SMF). Alternatively, during the uplink roaming data packet processing process of FIG. 2, the IP address of the roaming terminal (100) and the TEID allocated to the tunneling packet may be extracted from the S8-GTP tunneling data packet received from the visited network S-GW (203), and these may be mapped and have it.

The edge roaming switch (205) adds an S8-GTP tunneling header to an IP packet received from an edge service node (207) and converts it into a GTP tunneling data packet. At this time, a TEID matching the DIP (i.e., roaming terminal IP) in the IP packet received from the edge service node (207) is added, and an S8-GTP tunneling header is added in which the SIP is set to the edge roaming switch (205) and the DIP is set to the visited network S-GW (203). The edge roaming switch (205) transmits the converted S8-GTP tunneling data packet to the visited network S-GW (203).

The visited network S-GW (203) removes the GTP tunneling header of the S8-GTP tunneling data packet and restores it to an IP packet. Then, it adds an S1-GTP tunneling header to the restored IP packet and converts it to an S1-GTP tunneling data packet. At this time, the visited network S-GW (203) has a GTP tunneling ID (TEID) already assigned to the roaming terminal (100) during the session creation process. Therefore, the visited network S-GW (203) adds an S1-TEID matching the DIP (i.e., roaming terminal IP) in the restored IP packet and adds an S1-GTP tunneling header that sets the SIP to the visited network S-GW (203) and the DIP to the base station (201). The visited network S-GW (203) transmits the converted S1-GTP tunneling data packet to the base station (201).

The base station (201) removes the S1-GTP tunneling header from the S1-GTP tunneling data packet and restores it to an IP packet. Then, it adds an RLC header and a PDCP header to the restored IP packet and transmits it to the roaming terminal (100) through the DRB.

Through this process, the roaming terminal (100) receives a downlink roaming data packet from the edge service node (207).

FIG. 4 is a flowchart illustrating a DNS query operation of a roaming terminal according to an embodiment of the present invention.

Referring to Fig. 4, the GSLB server (309) registers the IP address of the edge service node (207) in the edge service target domain name (S101).

Thereafter, when the roaming terminal (100) wants to connect to the Internet network (500), it transmits a DNS query to the local DNS (307) (S103). The DNS query includes the domain name to which the roaming terminal (100) wants to connect.

If the queried domain name is registered, the local DNS (307) forwards a DNS query to GSLB (309) (S105).

The GSLB server (309) searches for an IP address corresponding to a domain name by specifying a domain name to be queried after the nslookup command (S107). At this time, since the IP address of the edge service node (207) is mapped to the domain name, the GSLB server (309) transmits a DNS response including the IP address of the edge service node (207) to the local DNS (307) (S109).

The local DNS (307) transmits the DNS response received in step S109 to the roaming terminal (100) (S111).

In this way, by assigning an IP address through the DSN lookup of GSLB (309), the transmission path of a specific roaming data packet related to an edge service/application can be dynamically controlled. FIG. 5 is a flowchart illustrating a registration process of an edge forwarding table for a low-latency edge roaming service according to an embodiment of the present invention.

Referring to Fig. 5, the visiting network-edge roaming controller (209) and the home network-edge roaming controller (305) perform a mutual authentication procedure (S201). The mutual authentication procedure is a procedure for authenticating valid access between network devices (209, 305). Since various known technologies can be used for the authentication method, specific details are omitted.

If the mutual authentication procedure is successful, the visited network-edge roaming controller (209) and the home network-edge roaming controller (305) perform a validity check to determine whether the edge forwarding tables they each have are identical, and if not, perform an update to make the edge forwarding tables mutually consistent (S203). For example, a home network operator or a visited network operator can register a new DIP to be provided as an edge service in the edge forwarding table. In this case, since the new DIP exists only in the visited network-edge roaming controller (209) or the home network-edge roaming controller (305), a process of sharing and updating it is performed.

The edge roaming switch (205) and the visit network-edge roaming controller (209) perform a mutual authentication procedure (S205). The mutual authentication procedure is a procedure for authenticating valid access between network devices (209, 305), and may be the same as the mutual authentication in step S201.

If the mutual authentication procedure is successful, the edge roaming switch (205) checks the validity of the edge forwarding table and performs an update in conjunction with the visiting network-edge roaming controller (209) (S207, S209).

The edge forwarding table may include information such as target DIP (destination IP address), next hop IP, and TTL (Time-to-live). Here, the next hop IP may be an L4 or L7 load balancer device of the edge service or an edge service node (207) depending on the implementation situation.

When new edge service information is registered in the edge forwarding table, the visit network-edge roaming controller (209) can send an API (Application Programming Interface) message notifying this to the edge roaming switch (205) in a push format using a communication protocol such as the SDN protocol, CLI TCP, JSON protocol, etc. For example, it can be sent using the RESTful API HTTP POST method.

In addition, the edge roaming switch (205) can make a request to the visited network-edge roaming controller (209) to check whether the edge forwarding table it has is valid when the TTL (Time-to-live) of the edge forwarding table it has expired, and can receive a valid edge forwarding table from the visited network-edge roaming controller (209) and update it. At this time, the edge roaming switch (205) can request the visited network-edge roaming controller (209) to check the validity of the edge forwarding table in a Pull format, for example, a RESTful API HTTP GET method.

The destination IP address registered in the edge forwarding table can be dynamically updated according to changes in the IP address of the edge service node (207).

FIG. 6 is a flowchart illustrating a series of procedures for providing a low-latency edge roaming service according to an embodiment of the present invention.

Referring to Fig. 6, a roaming terminal (100) transmits a roaming data packet having a specific service access address to the visited network S-GW (203) (S301).

The visiting network S-GW (203) transmits a roaming data packet to the edge roaming switch (205) (S303). At this time, as explained above, the transmitted roaming data packet is a GTP tunneling packet.

The edge roaming switch (205) determines whether the roaming data packet received in step S303 is a target service data packet defined in the edge forwarding table registered through the process of FIG. 5 (S305, S307).

If the edge roaming switch (205) is not a target service data packet defined in the edge forwarding table, it transmits the roaming data packet received in step S303 to the home network P-GW (301) (S309).

On the other hand, if the edge roaming switch (205) is a target service data packet defined in the edge forwarding table, it performs LBO to offload the roaming data packet received in step S303 to the edge service node (207) (S311).

In this way, if the edge service node IP address is registered as a target IP in the edge forwarding table existing in the visited network, roaming data packets can be offloaded to the visited network based on this IP.

The embodiments of the present invention described above are not implemented only through devices and methods, but may also be implemented through a program that realizes a function corresponding to the configuration of the embodiments of the present invention or a recording medium on which the program is recorded.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims (17)

A method for processing roaming data packets in an edge roaming switch located in a visiting network,
A step of receiving a roaming data packet transmitted by a roaming terminal from a data gateway of the above-mentioned visiting network;
A step for determining whether the destination IP address of the above roaming data packet is an edge service target registered in a pre-stored edge forwarding table;
If it is determined to be an edge service target, a step of offloading the roaming data packet to the edge service node of the visited network, and
If it is determined that the target is not an edge service target, a step of transmitting the roaming data packet to the data gateway of the home network is included.
The above edge service node,
A method for processing roaming data packets, which forms a low-latency edge path that is located in the above-mentioned access network and is connected to the edge roaming switch and the Internet network, and transmits roaming data packets transmitted from the edge roaming switch to the Internet network and transmits roaming data packets transmitted from the Internet network to the edge roaming switch so that they are transmitted to the roaming terminal. In paragraph 1,
Prior to the above receiving step,
A step of receiving the edge forwarding table from the edge roaming controller after performing mutual authentication with the edge roaming controller connected to the edge roaming switch and located in the visiting network.
A method for processing roaming data packets, further comprising: In paragraph 2,
The above edge roaming switch and the above edge roaming controller,
A method for processing roaming data packets, wherein the validity of the edge forwarding table is verified and updated based on a predefined communication protocol. In paragraph 2,
The above edge roaming switch and the above edge roaming controller,
A method for processing roaming data packets, which verifies and updates the validity of the edge forwarding table using the HTTP (HyperText Transfer Protocol) method. In paragraph 1,
The above receiving step is,
Receives a tunneling roaming data packet containing a tunneling header through a tunneling section formed with the data gateway of the above-mentioned visiting network,
The above judging steps are:
Determine whether the destination IP address confirmed from the IP header of the inner packet in the above tunneling roaming data packet is the target of the edge service.
The above offloading step is,
Offloading restored IP packets by removing tunneling headers from the above tunneling roaming data packets,
The step of transmitting to the data gateway of the above home network is:
A roaming data packet processing method for transmitting a tunneling roaming data packet received through the above tunneling section. In Article 5,
After the above offloading step,
A step of receiving an IP packet from the above edge service network,
A step of converting the above IP packet into a tunneling roaming data packet by adding a tunneling header to the above IP packet, and
Further comprising the step of transmitting the tunneling roaming data packet to the data gateway of the visited network,
The above tunneling roaming data packets are,
A method for processing a roaming data packet, wherein the data packet is transmitted from the data gateway of the above-mentioned visited network to a base station, restored to an original data packet with a tunneling header removed by the base station, and transmitted to the roaming terminal. In paragraph 1,
The above edge roaming switch,
Connected to the above-mentioned visit network data gateway and the above-mentioned home network data gateway respectively through the first interface,
The above first interface is,
A method for processing roaming data packets, defined as an interface connecting the above-mentioned visiting network data gateway and the above-mentioned home network data gateway. In paragraph 1,
The above edge roaming switch,
A method for processing roaming data packets, wherein the edge service node is connected through a second interface using an IP packet forwarding protocol defining a user plane. An edge roaming controller that manages an edge forwarding table that stores information about edge service targets, and
An edge roaming switch is included, which receives and stores the edge forwarding table from the edge roaming controller, is located between the visited network data gateway and the home network data gateway, receives uplink roaming data from a roaming terminal located in the visited network through the visited network data gateway, determines whether the uplink roaming data is a target of an edge service based on the edge forwarding table, and, if determined to be a target of the edge service, performs local breakout routing of the uplink roaming data to an edge service node.
The above edge service node,
An edge roaming system, which is located in the above-mentioned access network and is connected to the edge roaming switch and the Internet, and forms a low-latency edge path for transmitting roaming data packets transmitted from the edge roaming switch to the Internet network and transmitting roaming data packets transmitted from the Internet network to the edge roaming switch so that they are transmitted to the roaming terminal. In Article 9,
The above edge forwarding table is,
An edge roaming system that is dynamically updated according to changes in the above edge service nodes. In Article 9,
The above edge roaming controller and the above edge roaming switch,
An edge roaming system that, if mutual authentication is successful, verifies the validity of the edge forwarding table and then proceeds with an update. In Article 9,
The above edge roaming switch,
An edge roaming system that routes the uplink roaming data to the home network data gateway when the destination of the uplink roaming data is not registered in the edge forwarding table. In Article 12,
The above edge roaming switch,
Communicates using the above-mentioned visit network data gateway and the above-mentioned home network data gateway and a tunneling protocol,
An edge roaming system that routes uplink roaming data in the form of tunneling data received from the above-mentioned visiting network data gateway to the above-mentioned home network data gateway. In Article 13,
The above edge roaming switch,
An edge roaming system that removes a tunneling header from uplink roaming data in the form of tunneling data received from the above-mentioned visiting network data gateway, restores it to an IP packet, and offloads the uplink roaming data in the form of the IP packet to the edge service node. In Article 14,
The above edge roaming switch,
An edge roaming system that adds a tunneling header to downlink roaming data in the form of IP packets received from the edge service node and transmits the same to the visited network data gateway. In Article 15,
The above edge roaming switch,
Store tunneling information matching the IP address of the roaming terminal,
An edge roaming system that adds a tunneling header based on tunneling information matching a source IP address included in the above downlink roaming data. In Article 9,
A local DNS located in the home network, which performs a DNS (Domain Name System) query for the IP address of the domain name requested by the roaming terminal in response to a request from the roaming terminal, and
Further comprising a GSLB (Global Server Load Balancing) server located in the above home network and providing an IP address according to the DNS query received from the local DNS,
The above GSLB server,
An edge roaming system that stores the IP address of the edge service node by mapping it to the domain name of a service that is locally breakout-routed to the edge service node.

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