JP7173461B2 - Gateway device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gateway device that performs processing for transmitting packets to communication targets existing in a network beyond a user terminal.

In recent years, the number of user terminals (hereinafter also referred to as UE (User Equipment)) equipped with communication functions such as smartphones is increasing. These user terminals communicate with a packet data network via a mobile core network, which is equipment of a communication company.

Regarding the method of transmitting packets addressed to the IP address assigned to the user terminal to the user terminal, in the case of the LTE communication standard adopted in current smartphones, etc., see the following Non-Patent Documents 1 to 3. disclosed.

3GPP TS 23.401 General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access (http://www.etsi.org/deliver/etsi_ts/123400_123499/123401/08.14.00_60/ts_123401v081400p.pdf ) 3GPP TS 29.274 3GPP Evolved Packet System (EPS); Evolved General Packet Radio Service (GPRS) Tunneling Protocol for Control plane (GTPv2-C) (http://www.etsi.org/deliver/etsi_ts/129200_129299/129274/12.06. 00_60/ts_129274v120600p.pdf) 3GPP TS 29.281 General Packet Radio System (GPRS) Tunneling Protocol User Plane (GTPv1-U)

FIG. 7 is a block diagram showing a conventional configuration relating to processing for transmitting packets to communication targets existing in a network beyond a user terminal. In this FIG. 7, UE is a user terminal. An eNB (also referred to as an eNodeB) is a base station responsible for wireless communication with user terminals. SGW is a Serving Gateway that has a function to relay signals required for communication between a device called MME and the C-plane, and a function to handle user data on the User-plane. be. PGW is a packet data network gateway (also known as PDN Gateway) that has the function of connecting the LTE communication network and the packet data network, and the function of allocating IP addresses to connected devices such as user terminals. It is said)). According to the LTE communication standard, a connection request is normally made to the PGW when the power of the user terminal is turned on, and an IP address is assigned to the user terminal when the connection is established.

Conventional communication standards are created with the assumption that only communication between user terminals and packet data networks is possible. , as shown in FIG. 7, it was necessary to connect the user terminal and the communication target by DNAT (Destination Network Address Translation). In DNAT, there is a problem that settings must be added each time communication targets 1 to n are added to the IP network of the user terminal. In addition, since the destination port must be specified, another setting must be added if the receiving port is different even if the target of communication has the same IP address, which is inconvenient. rice field.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a gateway device capable of transmitting a packet from a source to a communication target existing in a network beyond a user terminal without complicated settings. intended to

A gateway device according to the present invention transmits a packet from a source that has arrived via a packet data network to a communication target existing in a network beyond the user terminal via a user terminal having a unique identifier. A gateway device responsible for transmission processing, storing in advance as registered IP address information a combination of an identifier of the user terminal and at least one or more IP addresses assigned to the communication target using the user terminal. extracting the destination IP address contained in the packet from the transmission source, referring to the registered IP address information in the storage unit based on the extracted destination IP address, and extracting the destination IP address from the registered IP address information; and an identifier of the user terminal of the matching registered IP address information when the determining unit determines that the destination IP address matches any of the registered IP address information. a transmission packet generation unit that adds header information for transmission to the user terminal based on the original packet from the transmission source and encapsulates it to generate a transmission packet.

Further, the gateway device according to the present invention comprises a GTP tunnel generation unit for generating a GTP tunnel with the user terminal based on GTP, and the storage unit stores an identifier of the GTP tunnel generated by the GTP tunnel generation unit. and the identifier of the user terminal and/or the IP address of the user terminal as GTP tunnel information. The IP address of the user terminal is used to refer to the GTP tunnel information, and the identifier of the matching GTP tunnel is included in the header information.

Further, in the gateway device according to the present invention, the registered IP address information is information in which at least one or more IP addresses to be assigned to the communication object are registered in advance based on designation by the user of the user terminal and stored. It is characterized by

According to the present invention, a combination of a user terminal identifier and at least one IP address assigned to a communication target using the user terminal is stored in advance as registered IP address information, and is included in the packet from the transmission source. Refer to the registered IP address information based on the destination IP address, and if the destination IP address matches any of the registered IP address information, transmit to the user terminal based on the user terminal identifier of the matched registered IP address information. header information is attached to the original packet from the source and encapsulated to generate a transmission packet. It is possible to send packets from the source.

1 is a block diagram showing the configuration of a gateway device 10 according to the present invention; FIG. 1 is a block diagram showing the overall communication configuration when using a gateway device 10 according to the present invention; FIG. 4 is an explanatory diagram showing an example of header information attached to a transmission packet in the gateway device 10 according to the present invention; FIG. FIG. 4 is a sequence diagram of communication processing when the gateway device 10 according to the present invention is used; FIG. 4 is a flow chart diagram showing the flow of transmission packet generation processing in the gateway device 10 of this example. FIG. 4 is a block diagram showing another embodiment of the overall communication configuration when using the gateway device 10 according to the present invention; 1 is a block diagram showing the overall communication configuration when using a conventional gateway device; FIG.

[First embodiment]
An example of the gateway device according to the first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a gateway device 10 according to the present invention. As shown in FIG. 1 , the gateway device 10 includes an IP address assignment unit 11 , a GTP tunnel generation unit 12 , a storage unit 13 , a determination unit 14 and a transmission packet generation unit 15 . Note that the gateway device in this example refers to a gateway responsible for connection between a communication network used by a user terminal and a packet data network, and corresponds to, for example, a packet data network gateway (hereinafter referred to as PGW).

The IP address assigning unit 11 has a function of assigning an IP address to a user terminal based on a connection request from the user terminal. Methods of assigning IP addresses to user terminals include methods of assigning fixed IP addresses and methods of assigning IP addresses dynamically. It is conceivable that a connection request is made from the user terminal to the gateway device 10 at the timing, and an IP address is assigned to the user terminal when this connection request is made. Here, the user terminal has a unique identifier such as IMSI, which is a unique number attached to the SIM card in the smartphone, and when the IP address assigning unit 11 assigns an IP address to the user terminal, stores the combination of the identifier of the user terminal and the assigned IP address as UE IP address information.

The GTP tunnel generation unit 12 has a function of generating a GTP tunnel with the user terminal based on GTP. Here, GTP stands for GPRS tunneling protocol (General Packet Radio Service Tunneling Protocol), and a GTP tunnel is generated based on this GTP. A GTP tunnel is a method for faithfully transmitting a given packet to a destination as it is without considering the state of the content being communicated, and is also called a bearer. Generation of the GTP tunnel in this GTP tunnel generation unit 12 applies an existing method, and therefore, description of a specific method is omitted. A TEID as a GTP tunnel identifier is assigned to the generated GTP tunnel. A combination of the identifier of the GTP tunnel generated by the GTP tunnel generator 12 and the identifier of the user terminal is stored as GTP tunnel information. As the GTP tunnel information, instead of the identifier of the user terminal, or together with the identifier of the user terminal, the IP address of the user terminal assigned by the IP address assigning unit 11 may be stored. The GTP tunnel information also includes the IP address of the SGW to which the GTP tunnel is connected, in addition to the TEID as the identifier of the GTP tunnel.

The same tunnel generation function as the GTP tunnel generation unit 12 is also provided in the SGW and eNB in the latter stage of the PGW. Each of the SGW and eNB has a function of generating a GTP tunnel to the next device, and the generated GTP tunnel is given a GTP tunnel identifier. Also, the correspondence relationship between the identifier of the GTP tunnel until reaching the self device and the identifier of the GTP tunnel from the self device to the next device is stored. Then, when each device receives a packet, by referring to the stored information based on the GTP tunnel identifier described in the header information attached to the received packet, the tunnel to the next device is determined. The identifier and the IP address of the next device are extracted, and the header information of the received packet is rewritten and transmitted. By performing such processing, the packet is transmitted to the target user terminal.

The storage unit 13 has a function of storing data necessary for various processes performed in the information processing apparatus 10 and data obtained as a result of the processes. Also, the UE IP address information 131, the GTP tunnel information 132, and the registered IP address information 133, which will be described later, are stored in the storage unit 13. FIG. Note that the UE IP address information 131, the GTP tunnel information 132, and the registered IP address information 133 do not necessarily need to be held by the gateway device 10 itself, as long as they can be accessed during various processes of the gateway device 10. FIG.

The determination unit 14 extracts the destination IP address included in the packet from the transmission source, refers to the registered IP address information 133 of the storage unit 13 based on the extracted destination IP address, and confirms that the destination IP address is the registered IP address. It has a function of determining whether or not it matches any of the information. Here, the registered IP address information means information in which a combination of a user terminal identifier and at least one or more IP addresses assigned to communication targets existing in the network beyond the user terminal is registered. For this registered IP address information, for example, a method of executing registration processing in advance based on designation by the user regarding at least one or more IP addresses assigned to communication targets and storing the information can be considered. For the registration of the registered IP address information, for example, a dedicated website may be used. Also, at least one or more IP addresses registered as registered IP address information may designate an IP address band that collectively designates IP addresses in a predetermined band. These are stored as registered IP address information 133 in the storage unit 13, for example.

Here, the packet from the source includes the destination IP address. When this destination IP address designates the IP address of the user terminal itself registered as the UE IP address information 131, transmission can be performed by processing in a conventional gateway device. If the address specifies the IP address of the communication target that exists in the network ahead of the user terminal, the transmission cannot be performed as it is by the processing in the conventional gateway device. Therefore, in this example, the determining unit 14 refers to the registered IP address information 133 based on the destination IP address and determines whether or not the destination IP address matches any of the registered IP address information. If they do not match, the transmission process cannot be executed. On the other hand, if there is a match, it can be determined which user terminal identifier the destination IP address is combined with, so the determined user terminal identifier is used to determine the transmission target.

When the determination unit 14 determines that the destination IP address matches any of the registered IP address information, the transmission packet generation unit 15 transmits to the user terminal based on the user terminal identifier of the matching registered IP address information. It has a function of adding header information for the original packet from the transmission source and encapsulating it to generate a transmission packet. The header information attached to the original packet is information necessary for realizing transmission of the original packet to the user terminal having the identifier determined by the determination unit 14 .

For example, in the case of GTP, the header information includes the IP address of the SGW, which is the next device, and the identifier (TEID) of the GTP tunnel. In order to generate the header information, the transmission packet generation unit 15 refers to the GTP tunnel information 132 using the identifier of the user terminal that matches the destination IP address, and extracts the identifier of the matching GTP tunnel and the IP address of the SGW to be connected. Address is described as header information.

FIG. 2 is a block diagram showing the overall communication configuration when using the gateway device 10 according to the present invention. In this FIG. 2, UE is a user terminal. An eNB (also referred to as an eNodeB) is a base station responsible for wireless communication with user terminals. SGW is a Serving Gateway that has a function to relay signals required for communication between a device called MME and the C-plane, and a function to handle user data on the User-plane. be. PGW is a packet data network gateway (also known as PDN Gateway) that has the function of connecting the LTE communication network and the packet data network, and the function of allocating IP addresses to connected devices such as user terminals. It is said)). PGW in FIG. 2 is a part to which the gateway device 10 of this example is applied. In FIG. 2, when a packet from a transmission source is to be transmitted to communication target 1, conventionally, the packet is transmitted to the IP address of the UE, and the UE communicates with the communication target ahead by DNAT. , In this example, by registering in advance the IP addresses assigned to the communication targets 1 to n existing ahead of the UE, an environment such as a point-to-point VPN is realized between the transmission source and the communication target 1. It is characterized by

FIG. 3 is an explanatory diagram showing an example of header information attached to a transmission packet in the gateway device 10 according to the present invention. If the destination address designates a communication target existing ahead of the UE, the transmission packet generator 15 generates header information and attaches it to the original packet. The header information at that time is the identifier of the user terminal (for example, IMSI) obtained by referring to the registered IP address information 133 in the determination unit 14, and the UE IP address information 131 and GTP tunnel information in the transmission packet generation unit 15. 132 and the identifier of the GTP tunnel (eg TEID). Note that UDP in FIG. 3 is header information for the User Datagram Protocol. The identifier of the GTP tunnel makes it possible to designate a communication route to at least the device in the latter stage, ie, the SGW in the example of FIG.

FIG. 4 is a sequence diagram of communication processing when the gateway device 10 according to the present invention is used. In FIG. 4, first, when a packet specifying the IP address A of the communication target is transmitted from the source, the packet is received by the PGW. Based on the IP address A, the PGW refers to the registered IP address information 133 . If the IP address A is registered in the registered IP address information 133, the identifier of the UE registered in combination is acquired. The PGW also refers to the GTP tunnel information 132 based on the UE identifier. Get the TEID of the GTP tunnel and the IP address of the SGW. In referring to the GTP tunnel information 132, the UE IP address information 131 is referred to based on the UE identifier to acquire the UE IP address, and the GTP tunnel information 132 is referred to based on the UE IP address. You may make it The GTP header describes the TEID of the GTP tunnel and the IP address of the SGW. Then, the GTP header is attached to the original packet, encapsulated, and transmitted to the SGW.

In FIG. 4, the SGW that has received the encapsulated packet determines an appropriate eNB from the GTP header information and transmits the packet to that eNB. The eNB that received the packet determines an appropriate UE from the GTP header information and transmits the packet to that UE. Processing in the SGW and eNB that relay these packets is performed based on known methods. The UE that receives the packet removes the GTP header from the encapsulated packet and retrieves the original packet. Since the original packet has a header specifying the IP address A of the communication target, if the IP network ahead of the UE is properly routed, the packet will be forwarded to the communication target. That is, the UE must have a function of removing the GTP header from the transmission packet generated by the gateway device 10 of this example, extracting the original packet, and transferring the packet to the destination address specified by the original packet. be.

Next, the flow of transmission packet generation processing in the gateway device 10 of this example will be described. FIG. 5 is a flow chart showing the flow of transmission packet generation processing in the gateway device 10 of this example. The transmission packet generation processing in the gateway device 10 of this example starts when the gateway device 10 receives a packet from the transmission source. The gateway device 10 first extracts the destination address from the received packet (step S101). If the destination address specifies the UE, the packet is sent using existing techniques. If the destination address does not specify the UE, refer to the registered IP address information based on the destination address to acquire the matching UE identifier (step S102). Based on the acquired identifier of the UE, the UE IP address information is referenced to acquire the IP address of the UE (step S103). Note that this step S103 may be omitted if the IP address of the UE is not used for referencing the GTP tunnel information in the next step. Next, based on the acquired UE identifier or UE IP address, the GTP tunnel information is referred to acquire information necessary for generating a GTP header (step S104). Specifically, the TEID of the GTP tunnel and the IP address of the SGW are acquired. GTP header information is generated based on the information thus obtained, and the original packet is encapsulated with the GTP header information attached to generate a transmission packet (step S105). Finally, the generated transmission packet is transmitted to the SGW, which is the next device (step S106), and the process ends.

As described above, according to the gateway device 10 according to the first embodiment, a combination of a user terminal identifier and at least one IP address assigned to a communication target using the user terminal is used as registered IP address information. Registered IP address information stored in advance is referenced based on the destination IP address included in the packet from the transmission source, and when the destination IP address matches any of the registered IP address information, the matching registered IP address information header information for transmission to the user terminal is attached to the original packet from the transmission source and encapsulated to generate the transmission packet, so complicated settings are not required. It is possible to transmit a packet from the source to a communication target on the network beyond the user terminal.

That is, even when a packet specifying a destination address of a communication target existing ahead of the user terminal as viewed from the gateway device 10 is received, the registered IP address information is referred to to identify the user terminal ahead of the communication target. An existing packet is specified, and header information for transmitting the original packet to the user terminal is generated, attached to the original packet, encapsulated, and transmitted, thereby performing transmission from the gateway device 10 to the user terminal. While using the communication method of 1, it becomes possible to transmit packets to the communication target beyond that. This method requires the work of registering registered IP address information in advance, but since it is possible to freely change the settings within the range of using the registered IP address, connection was made by conventional DNAT. The complexity of setting is reduced as compared with the case.

[Second embodiment]
The gateway device 10 according to the first embodiment has been described assuming a user terminal such as a smartphone owned by an individual, but the gateway device 10 is not limited to this. FIG. 6 is a block diagram showing another embodiment of the entire communication configuration when using the gateway device 10 according to the present invention. The example shown in FIG. 6 is the case where the user terminal is a router with a unique identifier. In the communication configuration as shown in FIG. 6, the gateway device 10 is adopted as the PGW.

By adopting the gateway device 10 as the PGW, as shown in FIG. 6, when using a network device such as a router to which a SIM card can be attached, a server connected to the packet data network can be connected to the IP network. It becomes possible to communicate with the file server. At this time, even when communicating with different ports such as SSH and FTP, there is no need to add NAT settings. Also, when adding another server such as a Web server, specifying the destination within the IP address range eliminates the need to change the settings on the side of the gateway device 10 .

In the first and second embodiments, the IP address of the next device and the identifier (TEID) of the GTP tunnel are described as the header information attached to the packet. This is because the GTP adopted in the LTE communication standard is such a standard, and if the communication standard has different restrictions, the header information is not limited to this. That is, any header information may be used as long as it guarantees that the transmission process is properly performed to the target user terminal.

For example, in order to generate the header information, the transmission packet generating unit 15 refers to the UE IP address information 131 using the identifier of the user terminal that matches the destination IP address, and the IP address of the matching user terminal is sent to the header information. may be included in

In the first embodiment and the second embodiment, communication using a protocol called GTP, which is adopted in the LTE communication standard, is taken as an example. Although the description has been given as an example of the case where communication is performed via , it is not necessarily limited to this protocol and communication configuration. Even if other protocols or communication configurations are used, combinations of identifiers of user terminals and at least one or more IP addresses assigned to communication targets using the user terminals are registered in the gateway device 10 as registered IP address information. , when receiving a packet specifying a destination address of a communication target existing ahead of the user terminal when viewed from the gateway device 10, the registered IP address information is referred to specify the user terminal in front of the communication target, and If it is possible to apply the process of generating header information for transmitting the original packet to the user terminal, attaching it to the original packet, encapsulating it and transmitting it, even for configurations other than the LTE communication standard, It is possible to apply the present invention.

REFERENCE SIGNS LIST 10 gateway device 11 IP address assignment unit 12 GTP tunnel generation unit 13 storage unit 131 IP address information for UE 132 GTP tunnel information 133 registered IP address information 14 determination unit 15 transmission packet generation unit

Claims (3)

A gateway device that performs processing for transmitting a packet from a source that has arrived via a packet data network, via a user terminal having a unique identifier, to a communication target that exists in a network beyond the user terminal. There is
pre-stored as registered IP address information in which a combination of an identifier of the user terminal and IP address band information for collectively designating a band of a predetermined IP address to be assigned to the communication target using the user terminal is registered; a storage unit;
extracting the destination IP address included in the packet from the transmission source, referring to the registered IP address information in the storage unit based on the extracted destination IP address, and determining whether the destination IP address is any of the registered IP address information; a determination unit that determines whether or not they match;
When the determining unit determines that the destination IP address matches any of the registered IP address information, header information for transmission to the user terminal is transmitted based on the user terminal identifier of the matching registered IP address information. and a transmission packet generation unit that creates a transmission packet by encapsulating an original packet from the source. A GTP tunnel generation unit that generates a GTP tunnel with the user terminal based on GTP,
The storage unit has a function of storing a combination of the identifier of the GTP tunnel generated by the GTP tunnel generation unit and the identifier of the user terminal and/or the IP address of the user terminal as GTP tunnel information,
The transmission packet generation unit refers to the GTP tunnel information using the identifier of the user terminal that matches the destination IP address and/or the IP address of the user terminal, and includes the identifier of the matching GTP tunnel in the header information. 2. The gateway device according to claim 1. 3. The registered IP address information is information of a predetermined IP address range to be assigned to the communication object, which is stored in advance by performing registration processing based on designation by the user of the user terminal. The gateway device according to .

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