KR102123831B1 - Method for internal network connection in external network through keep alive trunking and apparatus thereof - Google Patents

Abstract

The present invention relates to a method for accessing an internal network in an external network through keep-alive trunking and an apparatus thereof. More particularly, the present invention is to provide a method and an apparatus for reducing traffic generated in a large amount due to transmission of individual keep-alive packets from an external server to all Internet of things (IoT) devices in a specific section by collecting all the keep-alive packets used to maintain sessions between external servers and the various IoT devices in the section in a private network environment using a home gateway and sending all the packets at once.

Description

METHOD FOR INTERNAL NETWORK CONNECTION IN EXTERNAL NETWORK THROUGH KEEP ALIVE TRUNKING AND APPARATUS THEREOF}

The present invention relates to a method and apparatus for accessing an internal network in an external network through keep-alive trunking, and more specifically, to establish a session between external servers and various IoT devices provided in the premises in a private network environment using a home gateway. A method and apparatus for reducing the traffic occurring in a large amount by transmitting individual keep alive packets from external servers to all IoT devices in a specific premises by collecting and sending all keep alive packets used for maintenance It is to provide.

In general, the keep-alive procedure is to periodically send packets without payload to maintain a session between end devices (servers and clients). If there is no packet exchange with each other for a specified period of time or there is no response from the keep-alive packets Disconnect.

The main reason for using keep-alive is to detect whether one of the end devices is in a state where communication is impossible, and to clean up the open connection state on only one side, which not only prevents unnecessary actions, but also ensures that you always receive event packets from the other party that do not know when to come. This is to keep the session.

At this time, the response delay of the session connection partner may take a lot of time to create a response message, there may be a variety of situations, such as when the connection partner closes or reboots due to system circumstances, the router is broken, or the cable is disconnected.

In addition, the general keep-alive operation can be used with OS support or by implementing a function directly in the application protocol.

For example, when sending a TCP packet, the keep alive option can be set and used according to the situation. In other words, in the case of the Linux OS, if the socket option (SO_KEEPALIVE) is set using setsockopt(), a keep-alive search packet is automatically sent if the connection remains idle for the time specified by tcp_keepalive_interval.

In normal socket communication, the session must remain until the response message is received or until the time specified by tcp_ip_abort_interval has elapsed. If the keep alive option is set, keep alive if the connection remains idle for the time specified by tcp_keepalive_interval. Send a search packet.

Keep-alive time should be greater than tcp_rexmit_interval time, but less than opponent's tcp_ip_abort_interval time.

In addition, keep-alive of the HTTP protocol is managed by the application protocol itself without the help of the OS. If the client continues to make a request at a given time to the server, the connection is extended, and if not, the connection is disconnected from the server. It is mainly used for the purpose of preventing this, since the performance decreases when it is generated.

However, the method of implementing the keep-alive operation as described above, mainly in a network environment using a public IP, as well as in a private network environment using a NAT (Network Address Translation) device sharing the IP, all servers and premises in the network Since all of the IoT devices of the device must maintain a one-to-one session all the time, all IoT devices in a specific premises have to be always in a standby state, thereby increasing power consumption, and thus there is a problem that battery management cannot be easily performed.

As a prior art for solving the problem of increasing power consumption in all IoT devices provided in the premises, there is US Patent Publication No. US 2011/0286373 (2011.11.24.).

The above prior art relates to cost reduction of NAT connection state keep-alive (COST REDUCTION OF NAT CONNECTION STATE KEEP-ALIVE), and a session connection between a device in a private network and an external device in an IP sharing environment through an IP router (i.e. a home gateway). When done, the TTL (Time To Live) value of the end device section and the NAT type are calculated to reach the TTL value of the keep-alive probe packet coming from the outside to the IP router only. If the keep-alive probe message continuously flows from the external device, the session table between the external device (server)-the IP router and the internal device can be maintained, so that the end-to-end session is also maintained. At the same time, since the number of keep-alives is reduced toward the terminal, it is possible to save the operating power of the terminal (especially the wireless device) and reduce the flow of unnecessary packets in the internal network.

The above prior art has the advantage of being able to perform a function without embedding a separate keep-alive proxy server inside the IP router, which is an intermediate device, and if the keep-alive response to the server does not go in a timely manner, the server does not close the session itself. The session between the device (server)-IP router-internal device is not destroyed.

However, as in the prior art, the method of calculating the TTL value and the NAT type and reaching the TTL value of the keep-alive probe packet coming from the outside to the IP sharer, as the cloud IoT service becomes active, multiple IoT devices inside the home are external one. When connecting and using the cloud server, the number of keep alive packets going from the external server to each IoT device in the premises increases, and the burden of processing the keep alive packet of the cloud server in charge of multiple premises is increased. Occurred.

Therefore, in the present invention, as in the prior art, as an external server, to solve a problem in which a large amount of traffic occurs as a result of sending individual keep-alive packets to the home gateway by the number of all IoT devices in the premises, using a home gateway In a private network environment, keep alive packets used to maintain a session between external servers and various IoT devices provided in the premises are collected and transmitted to the home gateway at a time, and from the home gateway to the home gateway through a separate application program. It is intended to provide a method and a device capable of performing session management of various IoT devices in a connected premises.

In particular, the present invention can reduce the traffic generated by transmitting individual keep-alive packets to all IoT devices in a specific premises between the external server and the home gateway, through which the network and communication equipment (ie cloud server, home gateway, etc.) While reducing the operating load of, it is possible to always connect remotely from the external network to the internal network.

The present invention was created to solve the above problems, and collects all keep alive packets used to maintain a session between external servers and various IoT devices provided in the premises in a private network environment using a home gateway. By trunking at a time, a large amount of traffic generated by transmitting individual keep-alive packets from an external server to all IoT devices in a specific premises is reduced, and the operation load of the network and communication equipment is reduced. It is an object of the present invention to provide a method and apparatus for making remote access possible at all times.

In addition, the present invention reduces the number of flows of a number of keep-alive probe (heartbeat) packets flowing between the external server and various IoT devices in the premises, thereby reducing the operation load of the network and the device, and extending the battery life of each IoT device. Another object is to provide a method and apparatus for the same.

In addition, the present invention tracks packet flows in various ways, such as login from an IoT device in the premises to an external server through a proxy at a home gateway, and tracks them in a variety of ways to perform constant and consistent remote access from external servers through a session once initiated Another object is to provide a method and apparatus for making it possible.

An internal network access method in an external network through keep-alive trunking according to an embodiment of the present invention is NAT based on a login request and response between each IoT device and a cloud server in a home gateway to which at least one IoT device is connected NAT table generation step of generating a table, in the home gateway, a keep alive request receiving step of receiving a keep alive request message for each IoT device from the cloud server as a keep alive trunking packet, and in the home gateway, the generated And a keep alive response step of performing a response to the keep alive request message to the cloud server with reference to NAT table information.

In addition, the keep-alive trunking packet is a collection of keep-alive packets for maintaining a session with each IoT device in the cloud server, and includes a port number for each IoT device, a keep-alive cycle time information, or a combination thereof. It characterized by including the load information.

In addition, the method may include, in the home gateway, confirming that a session is maintained according to a predetermined period with each IoT device connected to the home gateway, and updating the NAT table based on the checked information. Characterized in that it further comprises.

In addition, the NAT table update step, on the basis of the keep-alive state value between the home gateway and the cloud server, for the keep-alive packet from each IoT device to the cloud server in the home gateway, on behalf of the cloud server. It is characterized in that it is possible to reduce the number of keep alives to be performed between the cloud server and the home gateway by transmitting the keep alive responses to the respective IoT devices.

In addition, the method may manage the NAT table including the ID, IP address, port number, keep-alive cycle time information, or a combination of the IoT devices for each IoT device through an application program installed in the home gateway. And performing a keep alive response based on the NAT table information without keep alive forwarding to each IoT device according to the keep alive request for each IoT device of the cloud server.

In addition, the internal network access device in the external network through keep-alive trunking according to an embodiment of the present invention, a NAT table management unit for generating a NAT table based on a login request and response between each IoT device and a cloud server, the cloud A keep alive request confirmation unit for receiving and confirming a keep alive request message for each IoT device in a keep alive trunking packet from a server, and a response to the keep alive request message to the cloud server by referring to the generated NAT table information Characterized in that it comprises a keep alive response unit to perform.

In addition, the device is characterized in that the application program mounted on the home gateway to which each IoT device is connected.

In addition, the keep-alive trunking packet is a collection of keep-alive packets for maintaining a session with each IoT device in the cloud server, and includes a port number for each IoT device, a keep-alive cycle time information, or a combination thereof. It characterized by including the load information.

In addition, the NAT table management unit, it characterized in that it further comprises confirming that the session is maintained according to each IoT device and a predetermined period, and updating the NAT table based on the checked information.

In addition, when updating the NAT table, the NAT table management unit, based on the keep-alive status value between the home gateway and the cloud server, for the keep-alive packet from each IoT device to the cloud server. Instead, it is possible to reduce the number of keep alives to be performed between the cloud server and the home gateway by sending the keep alive responses to the respective IoT devices.

In addition, the device performs management of the NAT table including each IoT device ID, IP address, port number, keep alive cycle time information, or a combination thereof, and keeps alive for each IoT device of the cloud server. It is characterized by performing a keep alive response based on the NAT table information without keep alive forwarding to each IoT device according to a request.

As described above, according to the method and apparatus for accessing an internal network in an external network through keep-alive trunking of the present invention, in a private network environment using a home gateway, a session is maintained between external servers and various IoT devices provided in the premises. Since all of the keep alive packets used to do so are collected and transmitted at once, traffic generated by transmitting individual keep alive packets from an external server to all IoT devices in a specific premises can be significantly reduced, thereby communicating with the network. The operation load of the equipment can be reduced, and there is an effect that a remote connection is always possible from the external network to the internal network.

In addition, since the present invention can smoothly process the internal network connection from the external network using keep-alive trunking, there is an effect that can easily manage the home gateway to which various IoT devices in the premises are connected.

1 is a diagram for explaining a P2P method keep-alive process in which a home gateway is not involved.
2 is a view for explaining a keep-alive procedure for creating and maintaining a session between a cloud server via a home gateway and an internal IoT device.
3 is a diagram for explaining a method for a user terminal to remotely access an IoT device in the premises through a cloud server.
4 is a view for explaining an internal network access device in an external network through keep-alive trunking according to an embodiment of the present invention.
5 is a view showing in more detail the configuration of the keep-alive agent installed in the home gateway according to an embodiment of the present invention.
6 is a view showing in more detail the configuration of a cloud server according to an embodiment of the present invention.
7 is a view for explaining an asynchronous process through keep alive trunking processing in a keep alive proxy device installed in a home gateway according to an embodiment of the present invention.
8 is a view for explaining keep alive trunking processing in a keep alive proxy device installed in a home gateway according to another embodiment of the present invention.

Hereinafter, a preferred embodiment of a method and apparatus for connecting an internal network in an external network through keep-alive trunking of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in each drawing denote the same members. In addition, specific structural or functional descriptions of the embodiments of the present invention are exemplified for the purpose of describing the embodiments according to the present invention, and unless defined otherwise, all terms used herein, including technical or scientific terms. They have the same meaning as those generally understood by those of ordinary skill in the art. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined herein. It is desirable not to.

1 is a diagram for explaining a P2P method keep-alive process in which a home gateway is not involved, and FIG. 2 is a description of a keep-alive procedure for creating and maintaining a session between a cloud server via the home gateway and an internal IoT device. It is for drawing.

As illustrated in FIG. 1, first, when each IoT device in the premises connected to the home gateway performs a login request to a remote cloud server, the cloud server performs a response to this, and in this process, the home gateway uses a NAT table. To create. At this time, in FIG. 1, three IoT devices will be described as an example, but the present invention is not limited thereto, and a much larger number of IoT devices may be used.

In addition, the cloud server requests keep-alive to each IoT device to maintain a session with each IoT device, and the home gateway forwards the keep-alive request from the cloud server to each IoT device, and then By sending the keep-alive response of the IoT device to the cloud server, a session is always maintained between the cloud server and each IoT device. That is, the message is transmitted between the cloud server and each IoT device to maintain the connectivity.

In the keep-alive request and response process, the home gateway continuously updates the NAT table created in the login request and response process.

However, since such a conventional keep-alive process must always maintain a session between the cloud server and the IoT device, all the IoT devices in the premises connected to the home gateway are always in a standby state, which increases the power consumption, which causes each to increase. Battery management of IoT devices had a difficult problem.

Also, in order to solve the battery consumption problem of each IoT device installed in the premises, a method of calculating the TTL value and NAT type and applying the TTL value of the keep-alive probe packet coming from the outside to the home gateway, which is an IP sharer, was applied. In addition, there was a problem in that a large amount of traffic occurs due to an increase in the number of keep-alive packets exchanged with each IoT device in the cloud server.

On the other hand, in order to deliver commands or execution commands for consistently controlling various IoT devices installed in the premises at a remote cloud server, one session must be created between the cloud server and the IoT device, and this session must always be maintained.

At this time, the IoT devices are valves, servo devices, alarms, lights, switches, air conditioners, door locks, and various sensors, and are driven by receiving control or execution commands from the cloud server.

In addition, NAT or NAPT type home gateways basically require out-bound packets to allow inbound packets from remote cloud servers to internal IoT devices through this session, but use port forwarding techniques such as virtual servers. If you do, you can create a remote access session with or without an outgoing session. However, there is a hassle of manually configuring the port forwarding technique.

As shown in FIG. 2, in order to automatically create and maintain a session between the cloud server and each IoT device installed in the premises, a session is created with an outbound packet, and then a keep server is used to keep the cloud server and home gateway. And the session connected to each IoT device should not be timed out.

In particular, since the service port number dynamically generated in the home gateway's NAPT table (IP/port forwarding table) created during the login process is limited to approximately 600 seconds, packets are sent from external cloud servers to internal IoT devices at random times. In order to send, inbound or outbound packets must be kept alive within a limited time.

In the present invention, the session creation between the external cloud server and the internal IoT device complies with the existing NAPT mechanism, but the keep-alive method for maintaining the session is an intermediate network device that performs the keep-alive operation performed by the end device in the existing P2P method. It is intended to be performed through a keep-alive agent installed in the in-home gateway. (See FIG. 4 below)

Basically, the keep-alive proxy service proposed by the present invention is suitable for a case where a plurality of IoT devices installed in the premises are concentrated with packets to an external cloud server. For example, a 1:n keep alive probe packet that exists between n internal IoT devices and an external cloud server is bundled and processed at a time. In the present invention, a keep alive trunking processing method will be described.

Meanwhile, an example of a method of initially forming a P2P session between each IoT device installed in a premises connected to a home gateway and an external cloud server and a remote access method will be described with reference to FIG. 3 as follows.

3 is a diagram for explaining a method for a user terminal to remotely access an IoT device in the premises through a cloud server.

As shown in FIG. 3, when performing a remote connection to each IoT device installed in the premises with a user terminal on which a smart home app (APP) is installed, the user terminal acquires a related service port number from a cloud server.

Thereafter, if the user terminal attempts remote access to the service port number obtained from the cloud server, the home gateway can access the home without much difficulty.

However, even in this case, it indicates that remote access is possible only when the service port is maintained through continuous keep alive between the cloud server and each IoT device installed in the premises.

As described above, the present invention, in order to reduce a large amount of traffic generated by transmitting individual keep-alive packets from an external cloud server, which is an existing problem, to all IoT devices in a specific premises, keep in a private network environment using a home gateway. By applying the live trunking method, all keep alive packets used to maintain a session between external cloud servers and various IoT devices provided in the premises are collected and transmitted to a home gateway at a time, and a specific program installed in the home gateway Alternatively, the keep-alive trunking packet transmitted at one time through the application (keep-alive agent in FIGS. 4 and 5 below) is managed to facilitate remote access from cloud servers to various IoT devices in the premises connected to the home gateway. It is intended to provide a method and apparatus capable of being performed.

Through this, the number of keep-alive probe (heartbeat) packets flowing between the inside and outside of the home gateway (IP router) is reduced to reduce the operation load of the network and communication equipment, and also increases the battery life of various IoT devices inside. It is a main feature of the present invention to always allow remote access from an external network to an internal network.

4 is a view for explaining an internal network access device in an external network through keep-alive trunking according to an embodiment of the present invention.

As shown in FIG. 4, the device of the present invention includes a home gateway 100, a keep-alive agent 200, a cloud server 300, an IoT device 400, a database 500, and the like.

The home gateway 100 is a device that interconnects or relays an access network of a wired/wireless network and a subscriber access network such as various digital subscriber lines and cables, and an keep-alive device 200 in the form of an application program is provided therein. .

The keep alive proxy device 200 is an application program mounted on the home gateway 100 to which each IoT device 400 is connected, and the keep alive proxy device 200 is manufactured in an independent configuration and the home It may also be used to access the gateway 100.

In addition, the keep alive proxy device 200 is provided in the home gateway 100, performs communication with a plurality of cloud servers 300 through a network, and keeps alive for sessions requested by the cloud server 300. Performs the function of proxying the procedure.

In particular, the keep alive proxy device 200 in principle is to process the keep alive packet asynchronously between the external cloud server 300 and the plurality of IoT devices 400 inside. In addition, since each IoT device 400 connected to the home gateway 100 basically opens and listens to a service port, in the present invention, the home gateway 100 is connected to the internal network. There is no need to inform each IoT device 400 to keep a session with keep alive.

That is, the keep-alive agent 200 generates a NAT table based on a login request and a response between each IoT device 400 and the cloud server 300, and each IoT device from the cloud server 300 ( 400) Each keep-alive request message is transmitted as a keep-alive trunking packet, and the keep-alive packet is not generated and forwarded to each IoT device 400 connected to the internal network, but is generated and managed with reference to the managed NAT table information to the cloud The server 300 performs a response to the keep alive request message (see FIG. 7).

In this case, the keep-alive trunking packet refers to a packet that collects and transmits keep-alive packets for maintaining a session with each IoT device 400 in the cloud server 300. In addition, the NAT table is information including ID, IP address, port number, keep alive cycle time information for each IoT device 400, or a combination thereof.

In more detail, the keep alive proxy device 200 generates a NAT table based on a login request and a response between the plurality of IoT devices 400 and the cloud server 300, and then the cloud server 300 Keep-alive packets from are all trunked at one time and received as a single message. At this time, if there are n IoT devices 400 that need keep alive in the premises network, the one message contains the content of keep alive requests for n or less IoT devices 400. At this time, the general one-to-one keep alive packet used in the past does not have payload information, but the keep alive packet applied to the present invention includes a payload including a port number for each IoT device 400, keep alive cycle time information, or a combination thereof. Information may be included.

In addition, the keep alive proxy device 200 always confirms that the link between the plurality of IoT devices 400 connected to the internal network and the home gateway 100 is maintained, and based on this, the cloud server 300 ) To respond to the keep alive request message sent from.

Also, the keep alive proxy device 200 maintains a link between the home gateway 100 and the cloud server 300 for keep alive packets directed from the plurality of IoT devices 400 to the cloud server 300. On the basis of the value, a response may be transmitted to the plurality of IoT devices 400 on behalf of the cloud server 300, and between the cloud server 300 and the plurality of IoT devices 400 may be transmitted through this method. It can reduce the number of keep alives that need to be done.

In addition, since the plurality of IoT devices 400 basically always open a listening port, the proxy function of the keep alive proxy device 200 can reduce unnecessary keep alive messages and reduce power consumption of operation. There is an advantage.

In addition, the keep alive proxy device 200 updates the keep alive between the timer and the IoT device 400 inside the timer for performing time management for updating the NAT table according to the request and response to the keep alive with the external cloud server 300. And a timer for performing time management for updating the NAT table according to the response, respectively. At this time, the keep alive agent device 200 often maintains a session at all times because both timers remove only expired sessions from the home gateway 100, thereby reducing the event of re-login for remote access, In addition, there is an advantage that a remote access service session can be used with each of the IoT devices 400 that are connected to the internal network at any time by an external third device (smartphone app (APP)).

On the other hand, the keep alive proxy device 200, in addition to the method of processing the keep alive packet asynchronously, whenever a keep alive packet comes from the cloud server 300, the plurality of IoT devices 400 connected to the internal network at this time ), and may be operated in a manner to collectively deliver it to the cloud server 300 according to the response transmitted from the plurality of IoT devices 400. (See FIG. 8) However, such a method is unnecessary. It is noted that it is not a recommended operation method since it may cause a flow of keep-alive packets and may increase battery consumption of the plurality of IoT devices 400.

In addition, the keep-alive agent 200 is at least once within this finite time because the retention time of the individual port information of the NAT or NAPT table is finite (approximately 600 seconds) when the home gateway 100 has no general proxy function. By performing keep alive, the session connected to the external network and the internal network must be maintained as the NAPT table of the home gateway 100, but if necessary, the port life of NAT or NAPT is greatly increased through the cloud server 300. Since control is possible, the number of keep alives can be adjusted.

In addition, the keep alive agent device 200 may perform a maintenance request for a specific session by a request of the cloud server 300 (symmetrically also possible by a request of a plurality of IoT devices 400 connected therein). When the virtual server or the port forwarding ALG program in the home gateway 100 has the same effect as the resource request by uPnP (universal plug and play), the web UI is opened and accessed remotely whenever the user installs the IoT device cumbersomely. This eliminates the hassle of configuring services.

The cloud server 300 includes a commonly referred web server, and transmits a keep alive request message for each IoT device 400 as a keep alive trunking packet to the keep alive proxy device 200, and Based on the response to the keep alive request message provided from the keep alive proxy device 200, the keep alive with each IoT device 400 is processed.

The plurality of IoT devices 400 are valves, servo devices, alarms, lights, switches, air conditioners, door locks, and various sensors connected to the home gateway 100 through an internal network, through the home gateway 100 The cloud server 300 receives and operates a control command or an execution command.

The database 500 stores, manages, and updates various operation programs used in the home gateway 100, the keep-alive agent server 200, and the cloud server 300.

5 is a view showing in more detail the configuration of the keep alive agent 200 installed in the home gateway according to an embodiment of the present invention.

As shown in FIG. 5, the keep alive proxy device 200 is an application program mounted on the home gateway 100 to which each IoT device 400 is connected, a NAT table management unit 210, a communication unit ( 220), a keep alive request confirmation unit 230, a keep alive response unit 240, a first timer 250, a second timer 260, a memory 270, and the like.

In addition, although the keep-alive agent 200 is not shown in the drawings, a power supply unit for supplying operating power to each component, an input unit for data input for various functions, an update management unit for managing updates of various operation programs, etc. are added. It can contain as.

The NAT table management unit 210 generates a NAT table based on a login request and response between each IoT device 400 and the cloud server 300, and stores the NAT table in the memory 270 for management. .

In addition, the NAT table management unit 210 may confirm that the session is maintained according to each IoT device 400 and a preset period, and update the NAT table based on the checked information.

In this case, the NAT table may include information including ID, IP address, port number, keep alive cycle time information for each IoT device 400, or a combination thereof.

Meanwhile, the NAT table management unit 210 keeps a keep alive state value between the home gateway 100 and the cloud server 300 for a keep alive packet directed from the IoT device 400 to the cloud server 300. Based on the basis of the cloud server 300, the keep-alive response can be transmitted to each IoT device 400 itself. Accordingly, the number of keep alives to be performed between the cloud server 300 and the home gateway 100 can be reduced.

The communication unit 220 receives the keep alive request message for each IoT device 400 from the cloud server 300 in a keep alive trunking packet and transmits the keep alive request message to the keep alive request confirmation unit 230.

In this case, the keep-alive trunking packet is a packet of keep-alive packets for maintaining a session with each IoT device 400 in the cloud server 300. Also, the keep-alive trunking packet may include port numbers for each IoT device 400, pay-alive information including keep-alive cycle time information, or a combination thereof.

In addition, the communication unit 220 transmits a response signal to the keep alive request message to the cloud server 300 through the control of the keep alive response unit 240. At this time, the response signal may be transmitted as a keep alive trunking packet, similar to the keep alive request message.

The keep alive request confirmation unit 230 performs a function of receiving and confirming a keep alive request message for each IoT device 400 from the cloud server 300 as a keep alive trunking packet through the communication unit 220. .

The keep alive response unit 240 generates a response signal for a keep alive request message for each IoT device 400 checked by the keep alive request confirmation unit 230 to generate a response signal for the cloud server through the communication unit 220 ( 300).

That is, the keep alive response unit 240 refers to the NAT table information generated and managed by the NAT table management unit 210 and performs a response to the keep alive request message to the cloud server 300.

At this time, the keep-alive response unit 240 is in the memory 270 without keep-alive forwarding to each IoT device 400 according to the keep-alive request for each IoT device 400 of the cloud server 300. It is desirable to perform a keep alive response based on the stored NAT table information.

The first timer 250 is a timer that performs time management for NAT table update according to a keep alive request and response from the keep alive proxy device 200 with the cloud server 300.

The second timer 260 is a timer that performs time management for updating the keep-alive with the respective IoT devices 400 connected to the internal network from the keep-alive agent 200 and updating the NAT table according to the response. .

In this case, the keep-alive agent 200 removes only the sessions in which both the first timer 250 and the second timer 260 have expired from the home gateway 100. Therefore, since the number of sessions is maintained at all times, the re-login event for remote access can be reduced, and an external third device can perform remote access to each of the IoT devices 400 directly connected to the internal network at any time. It becomes possible.

In the memory 270, various operation programs used in the keep-alive agent 200 are stored, and NAT table information generated or updated by the NAT table manager 210 is stored.

6 is a view showing in more detail the configuration of the cloud server 300 according to an embodiment of the present invention.

6, the cloud server 300 includes a communication interface unit 310, a keep-alive trunking processing unit 320, a keep-alive request unit 330, a keep-alive confirmation unit 340, and a memory 350. And the like.

Also, although the cloud server 300 is not shown in the drawings, a power supply unit for supplying operating power to each component, an input unit for data input for various functions, an update management unit for managing updates of various operation programs, and an external third party It may further include a communication connection unit for supporting remote access to each IoT device 400 connected to the internal network from the device (for example, the user terminal) of the.

The communication interface unit 310 keeps the keep alive request message for each IoT device 400 through the network through the control of the keep alive request unit 330 through the network. To be transferred.

In addition, the communication interface unit 310 receives a response signal to the keep alive request message from the keep alive proxy device 200 through a network, and transmits it to the keep alive confirming unit 340. At this time, the response signal is a trunking packet bound together as in the keep alive request message, and is generated and transmitted by the keep alive proxy device 200 in place of each IoT device 400.

The keep alive trunking processing unit 320 generates a keep alive trunking packet that bundles a keep alive request message for each IoT device 400 into one, and transmits the keep alive trunking packet to the keep alive request unit 330.

That is, the keep-alive trunking processing unit 320 generates a keep-alive trunking packet in which the keep-alive packets for maintaining a session with each IoT device 400 are gathered together in the cloud server 300 based on a preset period.

The keep alive request unit 330 keeps a keep alive trunking packet, which is a keep alive request message for each IoT device 400, generated by the keep alive trunking processing unit 320 through the communication interface unit 310. It is to be transmitted to the alive proxy device 200.

The keep alive confirmation unit 340 is based on a response signal to the keep alive request message received from the communication interface unit 310 between the cloud server 300 and each IoT device 400 provided in the premises. Check the session.

In the memory 350, various operation programs used in the cloud server 300 are stored, and session information between the IoT devices 400 checked through the keep-alive checking unit 340 is stored.

Next, an embodiment of a method of accessing an internal network in an external network through keep-alive trunking according to the present invention configured as described above will be described in detail with reference to FIGS. 7 and 8. At this time, each step according to the method of the present invention can be changed in order by the environment or those skilled in the art.

7 is a view for explaining an asynchronous processing process through keep alive trunking processing in a keep alive proxy device installed in a home gateway according to an embodiment of the present invention, and FIG. 8 is a home according to another embodiment of the present invention It is a figure for explaining the keep alive trunking process in the keep alive proxy device installed in the gateway.

First, referring to FIG. 7, when each IoT device 400 connected to the home gateway 100 performs a login request to the cloud server 300 remotely located, the cloud server 300 responds to this. In the process of requesting and responding to the login, a NAT table is generated by the keep alive agent 200 mounted on the home gateway 100. In this case, in FIG. 7, two IoT devices are connected to the home gateway 100 as an example, but it is not limited thereto, and a large number of IoT devices may be connected to the home gateway 100 and used.

Thereafter, the cloud server 300 requests keep alive to maintain a session with each IoT device 400. In the present invention, the cloud server 300 requests keep alive for each IoT device 400. A message, that is, a keep alive trunking packet in which one keep alive packet for maintaining a session with each IoT device 400 is transmitted to the keep alive proxy device 200 through a network.

Then, the keep alive proxy device 200 refers to the generated NAT table information and responds to the keep alive request message to the cloud server 300.

That is, the keep alive proxy device 200 does not perform keep alive forwarding to each IoT device 400 according to the keep alive request for each IoT device 400 requested from the cloud server 300. The keep-alive response is performed based on the NAT table information. At this time, the keep alive agent device 200 performs a response to the keep alive request message to the cloud server 300 and updates and processes a timer outside the NAT table.

In addition, the response signal may be transmitted to the cloud server 300 in a packet that bundles a response related to session maintenance with each IoT device 400 as in the keep alive request message.

In addition, the keep alive proxy device 200, the home gateway 100 without performing a keep alive forwarding to the external network for the keep alive packet from the respective IoT device 400 to the cloud server 300 Based on the keep-alive status value between the cloud server 300 and the cloud server 300, the cloud server 300 sends the keep-alive response on its own to each IoT device, so the cloud server 300 and the home gateway ( 100) It is possible to reduce the number of keep alives to be performed in between.

Meanwhile, in the present invention, as described with reference to FIG. 7, in addition to a method of asynchronously processing a keep alive packet between the cloud server 300 and the plurality of IoT devices 400 in the keep alive proxy device 200 A method of forwarding the keep-alive agent 200 to the internal network and then transmitting the response of the internal network to the cloud server 300 may be used.

When this is described in detail with reference to FIG. 8, when each IoT device 400 connected to the home gateway 100 performs a login request to the cloud server 300 located remotely, the cloud server 300 In response to this, the keep-alive agent 200 generates a NAT table during the login request and response process.

Subsequently, if a keep alive request message is transmitted as a keep alive trunking packet to maintain a session with each IoT device 400 from the cloud server 300, the keep alive proxy device 200 will send the keep alive request message each time. Is forwarded to the plurality of IoT devices 400 connected to the internal network, and is collectively delivered to the cloud server 300 according to a response transmitted from the plurality of IoT devices 400.

However, the method described in FIG. 8 is not preferably used because it may cause unnecessary flow of keep-alive packets and battery consumption of each IoT device 400 may increase.

As described above, the present invention can reduce traffic generated by transmitting individual keep-alive packets from an external server to all IoT devices in a specific premises, thereby reducing the operational load of the network and communication equipment, and always from the external network to the internal network. Remote access is possible.

As described above, the present invention has been described with reference to the embodiment shown in the drawings, but this is only exemplary, and those skilled in the art to which the art pertains have various modifications and other equivalent embodiments You will understand that it is possible. Therefore, the technical protection scope of the present invention should be judged by the following claims.

100: home gateway 200: keep alive agent
210: NAT table management unit 220: communication unit
230: keep alive request confirmation unit 240: keep alive response unit
250: first timer 260: second timer
270: memory 300: cloud server
310: communication interface 320: keep alive trunking processing unit
330: keep alive request unit 340: keep alive confirmation unit
350: memory 400: IoT device
500: database

Claims (11)

A NAT table generation step of generating a NAT table based on a login request and response between each IoT device and a cloud server in a home gateway to which at least one IoT device is connected;
In the home gateway, a keep alive request receiving step of receiving a keep alive request message for each IoT device from the cloud server as a keep alive trunking packet; And
In the home gateway, a keep-alive response step of performing a response to the keep-alive request message to the cloud server with reference to the generated NAT table information. In the external network through keep-alive trunking. How to connect to the internal network. The method according to claim 1,
The keep alive trunking packet,
As a collection of keep-alive packets for maintaining a session with each IoT device in the cloud server,
A method of accessing an internal network from an external network through keep alive trunking, characterized by including port number for each IoT device, keep alive cycle time information, or a combination of payload information. The method according to claim 1,
The above method,
In the home gateway, each IoT device connected to the home gateway confirms that the session is maintained according to a preset period, and updates the NAT table based on the checked information. A method of accessing an internal network from an external network through keep-alive trunking. The method according to claim 3,
The NAT table update step,
In the home gateway, for each keep-alive packet from each IoT device to the cloud server, the keep-alive response is automatically generated on behalf of the cloud server based on the keep-alive status value between the home gateway and the cloud server. By transmitting to the IoT device, it is possible to reduce the number of keep-alives that must be performed between the cloud server and the home gateway. The method of accessing an internal network in an external network through keep-alive trunking. The method according to claim 1,
The above method,
Through the keep-alive agent device, an application program installed in the home gateway,
Manages the NAT table including each IoT device ID, IP address, port number, keep alive cycle time information, or a combination thereof,
In the external network through keep-alive trunking, characterized by performing a keep-alive response based on the NAT table information without keep-alive forwarding to each IoT device according to the keep-alive request for each IoT device of the cloud server. How to access the internal network. A NAT table management unit generating a NAT table based on a login request and a response between each IoT device and a cloud server;
A keep alive request confirmation unit for receiving and confirming a keep alive request message for each IoT device in the keep alive trunking packet from the cloud server; And
And a keep alive response unit performing a response to the keep alive request message to the cloud server with reference to the generated NAT table information. An internal network access device in an external network through keep alive trunking. The method according to claim 6,
The device,
An internal network access device in an external network through keep alive trunking, characterized in that it is an application program mounted on a home gateway to which each IoT device is connected. The method according to claim 6,
The keep alive trunking packet,
As a collection of keep-alive packets for maintaining a session with each IoT device in the cloud server,
An internal network access device in an external network through keep alive trunking, characterized in that it includes a payload information including port numbers for each IoT device, keep alive cycle time information, or a combination thereof. The method according to claim 6,
The NAT table management unit,
Confirming that the session is maintained according to each IoT device and a predetermined period, and further updating the NAT table based on the checked information, accessing the internal network in the external network through keep-alive trunking. Device. The method according to claim 9,
The NAT table management unit,
When updating the NAT table, for each keep device packet directed to the cloud server from each IoT device, a keep alive response is generated on behalf of the cloud server based on the keep alive state value between the home gateway and the cloud server. An internal network access device in an external network through keep alive trunking, characterized in that it is possible to reduce the number of keep alives to be performed between the cloud server and the home gateway by transmitting to each IoT device. The method according to claim 6,
The device,
Manages the NAT table including each IoT device ID, IP address, port number, keep alive cycle time information, or a combination thereof,
In the external network through keep-alive trunking, characterized by performing a keep-alive response based on the NAT table information without keep-alive forwarding to each IoT device according to the keep-alive request for each IoT device of the cloud server. Internal network connection device.

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