COMMUNICATION CONTROL DEVICE, COMMUNICATION CONTROL METHOD, AND COMMUNICATION CONTROL PROGRAM

Abstract

An edge control device (10) comprises: an acquisition unit (151a) that acquires switching information regarding the switching of an edge router that accommodates a user's terminal; a setting unit (151b) that sets DHCP packet blocking and multicast communication cancellation in a switching source edge router, when switching information is acquired; an input unit (151c) that inputs user setting information to a switching destination edge router when the DHCP packet blocking and the multicast communication cancellation are set; an instruction unit (151d) that instructs a pseudo DHCP server, which is a virtual server, to induce the user terminal to reacquire an IP address on the basis of the switching information; a reception unit (151e) that receives a notification that the instruction to induce reacquisition has been received from the pseudo DHCP server; and a deletion unit (151f) that deletes user setting information stored by the switching source edge router when a predetermined time has elapsed from the time when the notification that the instruction to induce reacquisition was received.

Description

[Technical Field]

[0001] The present invention relates to a communication control device, a communication control method, and a communication control program. [Background technology]

[0002] In carrier networks, edge routers accommodating user terminals ("user terminals" or "terminals" as appropriate) are switched ("maintenance relocation" as appropriate) for maintenance purposes at the convenience of the telecommunications carrier. When switching edge routers, the user configuration information ("user configuration" as appropriate) currently accommodated is deleted from the edge router from which the switch is made ("source edge router" as appropriate), and the same information is then entered into the edge router to which the switch is made ("destination edge router" as appropriate). For security purposes, unicast reverse path forwarding (uRPF) may be applied to edge routers in carrier networks, and its application is recommended by the IETF (Internet Engineering Task Force), a standardization organization for Internet-related technologies.

[0003] As a conventional technology, a technology has been proposed in which, when performing maintenance and relocation of edge routers in a carrier network, the edge control system works in conjunction with a DHCP (Dynamic Host Configuration Protocol) server system to complete the switchover in a short time while minimizing the impact on user communications services. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Nishiguchi et al., "Edge Router Maintenance and Relocation Method to Minimize Communication Outages," Proceedings of the 2021 Institute of Electronics, Information and Communication Engineers General Conference, B-6-68, Mar. 2021. Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned conventional technology leaves room for improvement in the maintenance and relocation of edge routers in carrier networks. For example, the conventional technology requires adding functions to both the edge control system and the DHCP server system, but adding functions is difficult when the respective devices are owned by different telecommunications carriers. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the communication control device of the present invention is characterized by comprising: an acquisition unit that acquires switching information regarding the switching of an edge router that accommodates a user's terminal; a setting unit that, when the acquisition unit acquires the switching information, sets the source edge router to block DHCP packets and cancel multicast communication; an input unit that, when the setting unit sets the blocking of DHCP packets and the cancellation of multicast communication, inputs the user's configuration information to the destination edge router; an instruction unit that, based on the switching information, instructs a pseudo DHCP server, which is a virtual server, to induce the terminal to re-acquire an IP (Internet Protocol) address; a reception unit that receives a notification from the pseudo DHCP server that the instruction to induce re-acquisition has been received; and a deletion unit that, when a predetermined time has elapsed since the time the notification of the instruction to induce re-acquisition was received, deletes the user's configuration information held by the source edge router.

[0007] Furthermore, a communication control method according to the present invention is a communication control method executed by a communication control device, and is characterized by including: an acquisition step of acquiring switching information regarding switching of an edge router accommodating a user's terminal; a setting step of configuring a source edge router to block DHCP packets and cancel multicast communication when the acquisition step has acquired the switching information; an input step of inputting the user's configuration information to a destination edge router when the setting step has configured blocking of DHCP packets and cancellation of multicast communication; an instruction step of instructing a pseudo DHCP server, which is a virtual server, to induce the terminal to re-acquire an IP address based on the switching information; an acceptance step of accepting a predetermined notification from the pseudo DHCP server based on the instruction to induce re-acquisition; and a deletion step of deleting the user's configuration information held by the source edge router when a predetermined time has elapsed since the time the notification of the instruction to induce re-acquisition was accepted.

[0008] Furthermore, a communication control program according to the present invention is characterized in that it causes a computer to execute the following steps: an acquisition procedure for acquiring switching information regarding switching of an edge router accommodating a user's terminal; a setting procedure for, if the acquisition procedure acquires the switching information, configuring the source edge router to block DHCP packets and cancel multicast communication; an input procedure for, if the setting procedure configures the blocking of DHCP packets and the cancellation of multicast communication, inputting the user's configuration information into the destination edge router; an instruction procedure for, based on the switching information, instructing a pseudo DHCP server, which is a virtual server, to induce the terminal to re-acquire an IP address; an acceptance procedure for accepting, from the pseudo DHCP server, a predetermined notification based on the instruction to induce re-acquisition; and a deletion procedure for deleting the user's configuration information held by the source edge router when a predetermined time has elapsed since the time the notification of the instruction to induce re-acquisition was accepted. [Effects of the Invention]

[0009] In the present invention, maintenance relocation of edge routers can be carried out effectively. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an edge control system according to the first embodiment. [Figure 2] FIG. 2 is a sequence diagram showing the flow of conventional edge control processing. [Figure 3] FIG. 3 is a block diagram illustrating an example of the configuration of the edge control device according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing a specific example of the reacquisition prompt instruction method according to the first embodiment. [Figure 5] FIG. 5 is a sequence diagram showing an example of the flow of edge control processing 1 according to the first embodiment. [Figure 6] FIG. 6 is a sequence diagram showing an example of the flow of edge control processing 2 according to the first embodiment. [Figure 7] FIG. 7 is a sequence diagram showing an example of the flow of edge control processing 3 according to the first embodiment. [Figure 8] FIG. 8 is a diagram illustrating a computer that executes a program. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of an edge control device (sometimes referred to as a "communication control device"), an edge control method (sometimes referred to as a "communication control method"), and an edge control program (sometimes referred to as a "communication control program") according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments described below.

[0012] [First embodiment] Below, we will explain the configuration of the edge control system related to the first embodiment, the configuration of the edge control device, a specific example of an address re-acquisition inducement instruction method, and the overall flow of the edge control processing, and finally explain the effects of the first embodiment.

[0013] 1. Configuration of Edge Control System 100 The configuration of the edge control system 100 according to the first embodiment will be described in detail using Fig. 1. Fig. 1 is a diagram showing an example of the configuration of the edge control system 100 according to the first embodiment. Below, an example of the overall configuration of the edge control system 100 will be shown, and then each process will be described.

[0014] 1-1. Example of the overall configuration of the edge control system 100 The edge control system 100 includes an edge control device 10, edge routers 20 (20A, 20B), user terminals 30 (30A, 30B, 30C, 30D), a DHCP server 40, a pseudo DHCP server 40V, user DBs (databases) 50 (50A, 50B), and a communication network 60 consisting of a core network 60A and an access network 60B. The edge control device 10, the edge router 20, the user terminals 30, the DHCP server 40, the pseudo DHCP server 40V, and the user DB 50 are communicatively connected via the communication network 60 or a predetermined communication network (not shown) by wire or wirelessly. The edge control system 100 shown in FIG. 1 may include a plurality of edge control devices 10 and a plurality of DHCP servers 40 or pseudo DHCP servers 40V.

[0015] (1-1-1. Edge control device 10) The edge control device 10 has a user DB 50A that manages user information, and inputs user configuration 21 such as a user SO (Service Order) into the edge router 20 (see FIG. 1(1)). In FIG. 1, the edge control device 10 inputs the user configuration 21 into the edge router 20B, but it is also possible to input the user configuration 21 into the edge router 20A. In addition, a link interface is introduced between the edge control device 10 and the DHCP server 40, and the edge control device 10 and the DHCP server 40 can send and receive various information to and from each other (see FIG. 1(2)).

[0016] When a linking interface is not introduced between the edge control device 10 and the DHCP server 40, or when the linking interface targets only a portion of the user terminals 30, the edge control device 10 executes processing using a pseudo DHCP server 40V. Details of the edge control processing by the edge control device 10 will be described later in [3. Flow of Edge Control Processing]. The edge control device 10 can also construct a pseudo DHCP server 40V.

[0017] (1-1-2.DHCP Server 40) The DHCP server 40 assigns an address to the user terminal 30 (see FIG. 1(3)). The DHCP server 40 also holds a DB 40B that manages user information, and communicates with the user terminal 30 after identifying the user (see FIG. 1(4)). The DHCP server 40 refers to the IP, DHCP option values, etc. when identifying the user.

[0018] (1-1-3. Edge Router 20) The edge router 20 applies uRPF for security reasons (see FIG. 1(5)). The edge router 20 also relays DHCP packets (see FIG. 1(6)). Each edge router belongs to the same broadcast domain.

[0019] (1-1-4. Pseudo DHCP server 40V) When the linking interface is not supported, the pseudo DHCP server 40V links with the edge control device 10 and the DHCP server 40 (see FIG. 1(7)). The pseudo DHCP server 40V is built on the resources of the edge control device 10 or on a cloud service, for example.

[0020] 1-2. Processing of the Edge Control System 100 The following describes the processes of the edge control system 100: DHCP blocking process, pseudo DHCP server cooperation process, and edge router setting deletion process. Note that the following processes can be executed in a different order. Also, some of the following processes may be omitted.

[0021] (1-2-1. DHCP blocking process) First, the edge control device 10 receives a switching execution instruction from a maintenance person M (not shown) who will perform maintenance relocation (switching execution instruction reception process), sets a DHCP blocking filter for the switching source edge router 20A (DHCP blocking filter setting process), and issues an RA (Router Advertisement) suppression command to delete the multicast setting (multicast setting deletion process).The edge control device 10 also inputs the user configuration 21 of the user SO etc. to the switching destination edge router 20B (user configuration input process).

[0022] As described above, the edge control device 10 can execute the DHCP blocking process by the switching execution instruction receiving process, the DHCP blocking filter setting process, the multicast setting deletion process, and the user configuration input process.

[0023] (1-2-2. Pseudo DHCP server linkage processing) Below, pseudo DHCP server cooperation methods 1 to 3 executed by the edge control device 10 will be explained, and the IP switching process executed by the edge router 20, the user terminal 30 and the DHCP server 40 will be explained.

[0024] (1-2-2-1. Collaboration Method 1) If a linking interface is not introduced between the edge control device 10 and the DHCP server, the edge control device 10 transmits an instruction to induce re-acquisition (reconfigure) of the IP address from the edge control device 10 to the pseudo DHCP server 40V (re-acquisition inducement instruction processing).Then, the edge control device 10 receives a completion notification transmitted from the pseudo DHCP server 40V that has received the instruction (completion notification reception processing).

[0025] As described above, in the pseudo DHCP server cooperation method 1, the edge control device 10 can execute the pseudo DHCP server cooperation process by the re-acquisition inducement instruction process and the completion notification reception process. Furthermore, when a cooperation interface is introduced between the edge control device 10 and the DHCP server 40, or when a cooperation interface that was not initially introduced is introduced, the edge control device 10 executes the re-acquisition inducement instruction process to the DHCP server 40 and receives a re-acquisition inducement completion notification from the DHCP server 40, similar to the technology shown in Non-Patent Document 1.

[0026] (1-2-2-2. Collaboration Method 2) When the cooperation interface is configured to cooperate with some of the user terminals 30, the edge control device 10 executes a re-acquisition inducement instruction process to the DHCP server 40 for the user terminals 30 that are the cooperation targets, and executes a re-acquisition inducement instruction process to the pseudo DHCP server 40V for the user terminals 30 that are not the cooperation targets. Then, the edge control device 10 executes a re-acquisition inducement completion notification reception process from the DHCP server 40 for the user terminals 30 that are the cooperation targets, and executes a completion notification reception process from the pseudo DHCP server 40V for the user terminals 30 that are not the cooperation targets.

[0027] As described above, in the pseudo DHCP server cooperation method 2, the edge control device 10 can execute the DHCP server cooperation process for the user terminal 30 that is the cooperation target by issuing a re-acquisition inducement instruction process to the DHCP server 40 and accepting a re-acquisition inducement completion notification from the DHCP server 40. On the other hand, for the user terminal 30 that is not the cooperation target, the edge control device 10 can execute the pseudo DHCP server cooperation process by issuing a re-acquisition inducement instruction process to the pseudo DHCP server 40V and accepting a completion notification from the pseudo DHCP server 40V.

[0028] (1-2-2-3. Collaboration Method 3) If only an existing interface is introduced between the edge control device 10 and the DHCP server 40, the edge control device 10 executes a re-acquisition inducement instruction process to the pseudo DHCP server 40V. Next, the pseudo DHCP server 40V converts the re-acquisition inducement instruction received from the edge control device 10 into a format that the existing interface can handle, and executes a re-acquisition inducement instruction process to the DHCP server 40. Next, the pseudo DHCP server 40V executes a re-acquisition inducement completion notification reception process from the DHCP server 40, and converts the re-acquisition completion notification received from the DHCP server 40 into a format that the existing interface can handle. Then, the edge control device 10 executes a re-acquisition inducement completion reception process from the pseudo DHCP server 40V.

[0029] As described above, in the pseudo DHCP server cooperation method 3, the edge control device 10 can execute the pseudo DHCP server cooperation process by issuing a re-acquisition inducement instruction process to the DHCP server 40 via the pseudo DHCP server 40V and receiving a re-acquisition inducement completion notification process from the DHCP server 40 via the pseudo DHCP server 40V.

[0030] (1-2-2-4. IP switching process) In the pseudo DHCP server cooperation methods 1 to 3 described above, if the edge control device 10 does not issue a re-acquisition inducement instruction to the DHCP server 40, the following IP switching process is executed. First, the edge router 20, user terminal 30, and DHCP server 40 start a switching process for user communications in response to a re-acquisition inducement instruction from the maintenance person M to the DHCP server 40 or a DHCP renew from the user terminal 30, and the switching process is executed for all user terminals 30, completing the IP switching process. Then, when the IP switching process is completed, the DHCP server 40 sends a re-acquisition inducement completion notification to the maintenance person M.

[0031] (1-2-3. Edge router setting deletion process) After receiving the completion notification from the pseudo DHCP server 40V and after a certain period of time has elapsed, the edge control device 10 deletes the user configuration 21 of the user SO and the like held by the source edge router 20A. That is, after the IP switching process for the user communication between the edge router 20, the user terminal 30, and the DHCP server 40 is completed, the edge control device 10 deletes the user configuration 21 held by the source edge router 20A (user configuration deletion process). At this time, the edge control device 10 deletes the aggregated address setting held by the source edge router 20A (aggregated address deletion process) and sets an aggregated address for the destination edge router 20B (aggregated address setting process). Furthermore, the edge control device 10 can also check the progress with the maintenance person M as necessary (progress confirmation process).

[0032] As described above, the edge control device 10 can execute the edge router setting deletion process by the user configuration deletion process, the aggregate address deletion process, the aggregate address setting process, and the progress status confirmation process. Finally, the edge control device 10 transmits a switching completion notification to the maintenance person M (switching completion notification process).

[0033] 1-3. Effects of the Edge Control System 100 Below, the edge control process and improvements that have been made using the linkage interface shown in Non-Patent Document 1 will be explained in order, and then the effects of the edge control system 100 will be described in detail.

[0034] (1-3-1. Conventional edge control processing) Using FIG. 2, an edge control process that introduces the collaboration interface shown in Non-Patent Document 1 will be described. FIG. 2 is a sequence diagram showing the flow of conventional edge control process. The following describes the switching execution instruction process, DHCP blocking process, IP switching process, setting deletion process, and switching completion notification process in that order. Note that FIG. 2 uses an example of DHCPv6 (Dynamic Host Configuration Protocol version 6) as the communication method, but DHCPv4 (Dynamic Host Configuration Protocol version 4) or the like may also be used. Also, in the example of FIG. 2, a collaboration interface is introduced between the edge control device 10 and the DHCP server 40. Here, the collaboration interface enables the edge control device 10 to issue a re-acquisition inducement instruction to the DHCP server 40, enables the DHCP server 40 to issue a re-acquisition inducement completion notification to the edge control device 10, and enables the edge control device 10 and the DHCP server 40 to acquire lease timer information from each other.

[0035] (1-3-1-1. Switching execution instruction processing) A maintenance technician M who performs the maintenance relocation transmits a switching execution instruction including switching information to the switching source edge router 20A, which is performing user communication (step S101) with the user terminals 30 (30A, 30B, 30C, 30D) (step S102). Here, users 1 to 4 use user terminals 30A to 30D, respectively. User 1's user terminal 30A and user 2's user terminal 30B belong to VNE (Virtual Network Enabler) #a1, and user 30C of user 3 and user 4's user terminal 30D belong to VNE #b1. Note that "#a1" and "#b1" indicate aggregate addresses.

[0036] (1-3-1-2. DHCP blocking process) The edge control device 10 sets a DHCPv6 blocking filter for the source edge router 20A to block DHCPv6 for users 1 and 2 (step S103), and issues an RA suppression command to delete the multicast setting (step S104). The edge control device 10 also issues a user configuration 21 for user SO and the like to the destination edge router 20B (step S105). Similarly, the edge control device 10 sets a DHCPv6 blocking filter for the source edge router 20A to block DHCPv6 for users 3 and 4 (step S106), issues an RA suppression command (step S107), and issues a user configuration 21 for user SO and the like to the destination edge router 20B (step S108). As described above, even if the maintenance person M issues a switching execution instruction only once, the edge control device 10 divides and executes the DHCP blocking process for each set unit (e.g., aggregated address).

[0037] As described above, by blocking DHCP and deleting multicast settings in advance, there are no adverse effects even when the user configuration 21 is input to multiple edge routers. For example, the above process prevents network bandwidth congestion and unexpected terminal behavior due to multiplexed distribution of video and other data from multiple edge routers 20 to terminals.

[0038] (1-3-1-3. IP switching process) In order to switch the IPv6 addresses of users 1 to 4, the edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the DHCP server 40 in which the linking interface is installed (step S109). Next, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement to the user terminals 30A to 30D (step S110). Subsequently, the user terminals 30A to 30D transmit DHCPv6 updates to the source edge router 20A and the destination edge router 20B in order to re-acquire the addresses. At this time, the destination edge router 20B relays the DHCP packets, updates the DHCP binding table of the destination edge router 20B, and re-assigns the IP addresses, thereby completing the switching of the user communication path (step S111). Then, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement completion notification to the edge control device 10 in which the linking interface is installed (step S112).

[0039] (1-3-1-4. Setting deletion process) The edge control device 10 deletes the user configuration 21 of the user SO etc. held by the source edge router 20A in order to delete the settings of the users 1 to 4 (step S113). At this time, the edge control device 10 deletes the settings of the aggregated addresses ("#a1", "#b1") held by the source edge router 20A (step S114), and sets the aggregated addresses ("#a1", "#b1") in the destination edge router 20B (step S115).

[0040] (1-3-1-5. Switching completion notification processing) When the setting deletion process is completed, the edge control device 10 transmits a switching completion notification to the maintenance person M who will perform the maintenance relocation (step S116).

[0041] (1-3-2. Improvements to conventional edge control processing) The following describes improvements to the edge control process that introduces the collaboration interface shown in Non-Patent Document 1, with reference to Fig. 2. The above edge control process has the following three improvements.

[0042] (1-3-2-1. Improvement point 1) As a first improvement, the above technology requires not only the addition of functions to the edge control device 10 but also the addition of a linking interface through which the DHCP server 40 receives instructions and notifies completion. That is, in the example of Fig. 2, it is necessary to add a linking interface for executing the re-acquisition inducement instruction process in step S109 and the re-acquisition inducement completion notification process in step S112.

[0043] (1-3-2-2.Improvement point 2) As a second improvement, the above technology requires the development and release of multiple systems, which can lead to a concentration of development periods, a longer development period due to interface adjustments between systems, and more complicated and difficult release adjustments due to an increase in the number of systems to be released. That is, in the example of Fig. 2, a burden can arise due to the development and release of the edge control system including the edge control device 10 and the DHCP server system including the DHCP server 40.

[0044] (1-3-2-3.Improvement point 3) As a third improvement, in the above technology, when the edge control device 10 and the DHCP server 40 are managed by different telecommunications carriers, even if it is decided to install a function in the edge control device 10, it is not possible to confirm the installation of the function in the DHCP server 40. That is, in the example of Fig. 2, it may be difficult to install a linkage interface between the edge control system including the edge control device 10 and the DHCP server system including the DHCP server 40.

[0045] (1-3-3. Overview of Edge Control System 100) In the edge control system 100, the edge control device 10 acquires switching information regarding the switching of the edge router 20 that accommodates the user terminal 30, sets the source edge router 20A to block DHCP packets and disable multicast communication, inputs user setting information (user config) to the destination edge router 20B, instructs the virtual server, pseudo DHCP server 40V, based on the switching information, to induce the user terminal 30 to re-acquire an IP address, accepts a completion notification from the pseudo DHCP server indicating that the instruction to induce re-acquisition has been received, and deletes the user config 21 held by the source edge router 20A if a predetermined time has elapsed since the completion notification was received.

[0046] In addition, in the edge control system 100, when the edge control device 10 is connected to a DHCP server 40, which is a physical server, via a specified interface in a compatible manner, it instructs the DHCP server 40 to induce re-acquisition, receives a notification of completion of the re-acquisition inducement from the DHCP server, and deletes the user configuration 21 held by the source edge router 20A.

[0047] In addition, in the edge control system 100, the edge control device 10 instructs the DHCP server 40 to induce re-acquisition for each predetermined unit (e.g., device, LAG, user) at predetermined time intervals, instructing the DHCP server 40 to induce re-acquisition for units that the DHCP server 40 can handle, and instructing the pseudo DHCP server 40V to induce re-acquisition for units that the DHCP server 40 cannot handle.

[0048] In addition, in the edge control system 100, the edge control device 10 sends to the DHCP server 40 an instruction to induce re-acquisition that has been converted into a form that can be handled by the pseudo DHCP server 40V, receives from the DHCP server 40 a notification of completion of the re-acquisition invitation that has been converted into a form that can be handled by the pseudo DHCP server 40V, and deletes the user configuration 21 held by the source edge router 20A.

[0049] (1-3-4. Effects of the edge control system 100) As described above, the edge control system 100 enables effective switching by introducing a corresponding function into the edge control device 10, without introducing a corresponding function into the DHCP server 40. In other words, even if a linking interface is not introduced between the edge control device 10 and the DHCP server 40, the edge control system 100 can complete switching in a short time while minimizing the impact on user communication services by using the pseudo DHCP server 40V.

[0050] Furthermore, after a corresponding function is introduced into the DHCP server 40, the edge control system 100 becomes capable of advanced switching without adding any further functions to the edge control device 10. In other words, when a linking interface is introduced between the edge control device 10 and the DHCP server 40, the edge control system 100 can use the DHCP server 40 to more effectively reduce the impact on user communications services and complete switching in a short time.

[0051] Furthermore, the edge control system 100 enables effective switching even when a partial support function is introduced into the DHCP server 40. That is, when an interface that enables cooperation with some users is introduced between the edge control device 10 and the DHCP server 40, the edge control system 100 uses the pseudo DHCP server 40V and the DHCP server 40 in combination, thereby enabling switching to be completed in a short time while minimizing the impact on user communication services.

[0052] Furthermore, the edge control system 100 enables effective switching without introducing a corresponding function into the DHCP server 40. That is, when only an existing interface is introduced between the edge control device 10 and the DHCP server 40, the edge control system 100 converts the form of notification between the pseudo DHCP server 40V and the DHCP server 40, thereby enabling switching to be completed in a short time while minimizing the impact on user communications services.

[0053] Furthermore, before the corresponding function is introduced into the DHCP server 40, the edge control system 100 may require more work by the maintenance personnel M during operation than with conventional technology, or the cost of the increased work by the maintenance personnel M may be high depending on the circumstances of the telecommunications carrier. However, the edge control system 100 also enables operation that avoids the increased work by the maintenance personnel M in exchange for accepting a longer time until the user communication path switching is completed.

[0054] As described above, the edge control system 100, by introducing a linking function of the pseudo DHCP server 40V into the edge control device 10, enables switching to be completed in a short time while minimizing the impact on user communications services, regardless of the status of function introduction into the DHCP server 40.

[0055] 2. Configuration of Edge Control Device 10 The functional configuration of the edge control device 10 according to the first embodiment will be described in detail below. An example of the configuration of the edge control device 10 according to the first embodiment and a specific example of a reacquisition inducement instruction method will be described below.

[0056] 2-1. Example of the configuration of the edge control device 10 An example of the configuration of the edge control device 10 according to the first embodiment will be described in detail with reference to Fig. 3. Fig. 3 is a block diagram showing an example of the configuration of the edge control device 10 according to the first embodiment. The edge control device 10 has an input unit 11, an output unit 12, a communication unit 13, a storage unit 14, and a control unit 15.

[0057] (2-1-1. Input section 11) The input unit 11 controls input of various information to the edge control device 10. The input unit 11 is, for example, a mouse or a keyboard, and receives input of setting information and the like to the edge control device 10.

[0058] (2-1-2. Output section 12) The output unit 12 controls the output of various information from the edge control device 10. The output unit 12 is, for example, a display, and outputs setting information stored in the edge control device 10, etc.

[0059] (2-1-3. Communications Department 13) The communication unit 13 controls data communication with other devices. For example, the communication unit 13 performs data communication with each communication device. The communication unit 13 can also perform data communication with an operator's terminal (not shown).

[0060] (2-1-4. Storage section 14) The storage unit 14 stores various information referenced when the control unit 15 operates and various information acquired when the control unit 15 operates. Here, the storage unit 14 is, for example, a semiconductor memory element such as a random access memory (RAM) or a flash memory, or a storage device such as a hard disk or an optical disk. Note that, in the example of Fig. 3, the storage unit 14 is installed inside the edge control device 10, but it may be installed outside the edge control device 10, or multiple storage units may be installed.

[0061] (2-1-5. Control unit 15) The control unit 15 controls the entire edge control device 10. The control unit 15 has an edge control unit 151 and a pseudo server control unit 152. Here, the control unit 15 is, for example, an electronic circuit such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0062] (2-1-5-1. Edge control unit 151) The edge control unit 151 includes an acquisition unit 151a, a setting unit 151b, an input unit 151c, an instruction unit 151d, a reception unit 151e, and a deletion unit 151f.

[0063] (Acquisition part 151a) The acquiring unit 151a acquires switching information related to switching of the edge router 20A that accommodates the user terminal 30. For example, the acquiring unit 151a acquires, as the switching information, information on the switching source edge router 20A, information on the accommodated user terminal 30, information on the switching destination edge router 20B, the purpose of switching of the edge router 20, the scheduled switching start time, the scheduled switching end time, etc. Meanwhile, the acquiring unit 151a may store the acquired switching information in the storage unit 14.

[0064] (Setting section 151b) When the acquisition unit 151a acquires switching information, the setting unit 151b sets the source edge router 20A to block DHCP packets and cancel multicast communication. For example, when the setting unit 151b acquires information about maintenance relocation of the source edge router 20A as the purpose of switching the edge router 20, the setting unit 151b sequentially sets the source edge router 20A to block DHCP packets and cancel multicast distribution.

[0065] (Insertion section 151c) When the setting unit 151b sets blocking of DHCP packets and cancellation of multicast communication, the input unit 151c inputs user setting information to the switching destination edge router 20B. For example, when the input unit 151c sets blocking of DHCP packets and cancellation of multicast distribution to the switching source edge router 20A that is being relocated for maintenance, the input unit 151c inputs information about individual user transfer settings, such as IP address settings, VLANs (Virtual Local Area Networks), and ACLs (Access Control Lists), to the switching destination edge router 20B that is being relocated for maintenance.

[0066] (Instruction part 151d) Based on the switching information, the instruction unit 151d instructs the pseudo DHCP server 40V to induce the user terminal 30 to re-acquire an IP address. Based on the switching information, the instruction unit 151d also instructs the DHCP server 40 to induce the user terminal 30 to re-acquire an IP address. For example, the instruction unit 151d instructs the user terminal 30 to induce the user terminal 30 to re-acquire an IP address for each predetermined unit at predetermined time intervals. The instruction unit 151d also instructs the user terminal 30 to induce the user terminal 30 to re-acquire an IP address for each device, LAG, or user. Note that re-acquisition inducement instruction processes using different instruction methods by the instruction unit 151d will be described later in [2-2. Re-acquisition inducement instruction method].

[0067] When the instruction unit 151d is connected to the DHCP server 40, which is a physical server, via a predetermined interface in a manner that allows it to handle the request, the instruction unit 151d instructs the DHCP server 40 to induce re-acquisition. Furthermore, the instruction unit 151d instructs the DHCP server 40 to induce re-acquisition for a predetermined unit that the DHCP server 40 can handle. Furthermore, the instruction unit 151d instructs the dummy DHCP server 40V to induce re-acquisition for a predetermined unit that the DHCP server 40 cannot handle. Furthermore, the instruction unit 151d transmits to the DHCP server 40 an instruction to induce re-acquisition that has been converted into a format that can be handled by the dummy DHCP server 40V. Note that the re-acquisition inducement instruction process by the instruction unit 151d using a different cooperation method will be described later in [3. Flow of Edge Control Process].

[0068] (Reception unit 151e) The reception unit 151e receives a notification from the pseudo DHCP server 40V that an instruction to induce re-acquisition of an IP address has been received. The reception unit 151e also receives a notification from the DHCP server 40 that the inducement to re-acquire an IP address by the user terminal 30 has been completed. For example, when the DHCP server 40 transmits a DHCP re-acquisition inducement to the user terminal 30, the reception unit 151e receives a notification that the inducement to re-acquire an IP address has been completed, the notification being transmitted by the DHCP server 40 to the edge control device 10. The reception unit 151e also receives a notification from the DHCP server 40 that the inducement to re-acquire an IP address has been completed, the notification being converted into a format that can be handled by the pseudo DHCP server 40V.

[0069] (Deleted section 151f) The deletion unit 151f deletes the user setting information held by the switching source edge router 20A when a predetermined time has elapsed since the time when the notification that an instruction to induce re-acquisition of an IP address was received was received. Furthermore, the deletion unit 151f deletes the user setting information held by the switching source edge router 20A when the reception unit 151e receives a notification that the induction of re-acquisition of an IP address by the user terminal 30 has been completed. For example, the deletion unit 151f deletes information related to individual user forwarding settings such as the IP address setting, VLAN, and ACL of the user terminal 30 that are stored in the switching source edge router 20A that is being relocated for maintenance.

[0070] (2-1-5-2. Pseudo server control unit 152) The pseudo server control unit 152 includes a construction unit 152a.

[0071] (construction unit 152a) The construction unit 152a can construct a pseudo DHCP server 40V, which is a virtual server. For example, the construction unit 152a constructs the pseudo DHCP server 40V on the resources of the edge control device 10. The construction unit 152a can also be constructed on an information processing device or a cloud service other than the edge control device 10. In this case, the construction unit 152a constructs a pseudo DHCP server 40V that can receive an invitation to re-acquire an IP address sent by the instruction unit 151d and can transmit to the reception unit 151e a notification that the instruction to induce re-acquisition of an IP address has been received.

[0072] [2-2. Reacquisition Inducement Instruction Method] The reacquisition inducement instruction method according to the first embodiment will be described in detail with reference to Fig. 4. Fig. 4 is a diagram showing a specific example of the reacquisition inducement instruction method according to the first embodiment. Below, the instruction message generation process performed prior to the reacquisition inducement instruction process will be described, and then three types of instruction methods and their advantages will be described.

[0073] (2-2-1. Instruction message generation process) First, the edge control device 10 acquires information about users involved in the maintenance relocation from the user DB 50A. At this time, the edge control device 10 acquires user identifiers {user identifier 1, user identifier 2, ... user identifier N} corresponding to N users as user information, and generates a re-acquisition inducement instruction message based on the user identifiers in the following manner. Note that the setting related to the method of the re-acquisition inducement instruction message can be changed statically or dynamically.

[0074] (2-2-2. Instruction method 1) In instruction method 1, the edge control device 10 transmits instruction messages including one user per message to the DHCP server 40. In the example of instruction method 1 in FIG. 4, the edge control device 10 transmits three instruction messages corresponding to user 1, user 2, and user 3. The time interval between transmissions of each message can be set arbitrarily (see instruction method 1 in FIG. 4). For example, the edge control device 10 transmits instruction messages using instruction method 1 when targeting individual users or when leveling the flow rate of reacquired packets to the L2 section.

[0075] (2-2-3. Instruction method 2) In instruction method 2, the edge control device 10 transmits an instruction message including multiple users per message to the DHCP server 40. In the example of instruction method 2 in Fig. 4, the edge control device 10 transmits one instruction message including all of {user 1, user 2, user 3, ...} (see instruction method 2 in Fig. 4). For example, in order to reduce the load on the edge control device 10, when instructing multiple target users at once, the edge control device 10 transmits an instruction message using instruction method 2.

[0076] (2-2-4. Instruction method 3) In instruction method 3, the edge control device 10 transmits a plurality of instruction messages including a plurality of users to the DHCP server 40. In the example of instruction method 3 in Fig. 4, the edge control device 10 transmits two instruction messages corresponding to {user 1, user 2, ...} and {user 10, user 11, ...}. The time interval between the transmission of each message can be set arbitrarily (see instruction method 3 in Fig. 4). When the edge control device 10 is to issue an instruction as a compromise between instruction method 1 and instruction method 2, it transmits an instruction message using instruction method 3.

[0077] (2-2-5. Advantages of giving instructions by unit) As described above, in the edge control system 100 according to the first embodiment, the edge control device 10 has a function of specifying a target user in a reacquisition inducement instruction from the edge control device 10 to the DHCP server 40, and can send an instruction message at any user unit and time interval. The opposing DHCP server 40 can induce the specified user to reacquire. Furthermore, the edge control device 10 can reduce the burst load caused by DHCP address reacquisition messages on the edge router and L2 section by limiting the target users (for example, by device unit, LAG unit, or user unit) and adjusting the time interval of the message.

[0078] [3. Edge control processing flow] The flow of edge control processing according to the first embodiment will be described in detail with reference to Figs. 5 to 7. Figs. 5 to 7 are sequence diagrams showing an example of the flow of edge control processing according to the first embodiment. Edge control processing 1 to 3 will be described below. Note that the processes described below can also be executed in a different order. Also, some of the processes described below may be omitted.

[0079] [3-1. Flow of Edge Control Process 1] The flow of the edge control process 1 according to the first embodiment will be described in detail with reference to Fig. 5. Although Fig. 5 uses an example of DHCPv6 as the communication method, DHCPv4 or the like can also be used. In the example of Fig. 5, it is assumed that no linking interface is introduced between the edge control device 10 and the DHCP server 40, or that even if a linking interface is introduced, it is not compatible.

[0080] (3-1-1. Switching execution instruction processing) A maintenance technician M who performs the maintenance relocation transmits a switching execution instruction including switching information to the switching source edge router 20A that is performing user communication (step S201) with the user terminals 30 (30A, 30B, 30C, 30D) (step S202). Here, users 1 to 4 use user terminals 30A to 30D, respectively. User 1's user terminal 30A and user 2's user terminal 30B belong to VNE#a1, and user 30C of user 3 and user 4's user terminal 30D belong to VNE#b1. Note that "#a1" and "#b1" indicate aggregate addresses.

[0081] (3-1-2. DHCP blocking process) The edge control device 10 sets a DHCPv6 blocking filter for the switching source edge router 20A to block DHCPv6 for users 1 and 2 (step S203), and issues an RA suppression command to delete the multicast setting (step S204). The edge control device 10 also issues user configurations 21 for user SO and the like to the switching destination edge router 20B (step S205). Similarly, the edge control device 10 sets a DHCPv6 blocking filter for the switching source edge router 20A to block DHCPv6 for users 3 and 4 (step S206), issues an RA suppression command (step S207), and issues user configurations 21 for user SO and the like to the switching destination edge router 20B (step S208). As described above, even if the maintenance operator M issues a switching execution instruction only once, the edge control device 10 divides and executes the DHCP blocking process for each set unit (e.g., aggregated address).

[0082] (3-1-3. Pseudo DHCP server collaboration process) The edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the dummy DHCP server 40V (step S209). Then, the edge control device 10 receives the completion notification transmitted from the dummy DHCP server 40V (step S210).

[0083] Here, the pseudo DHCP server 40V only executes the process of receiving a DHCPv6 re-acquisition inducement instruction and transmitting a completion notification, so the development cost is extremely low.

[0084] (3-1-4. IP switching process) First, the maintenance person M transmits a DHCPv6 re-acquisition inducement instruction to the DHCP server 40 in order to switch the IPv6 addresses of users 1 to 4 (step S211). Next, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement to the user terminals 30A to 30D (step S212). Subsequently, the user terminals 30A to 30D transmit a DHCPv6 update to the source edge router 20A and the destination edge router 20B in order to re-acquire the addresses. At this time, the destination edge router 20B relays the DHCP packet, updates the DHCP binding table of the destination edge router 20B, and re-assigns the IP addresses, thereby completing the switching of the user communication path (step S213). Then, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement completion notification to the maintenance person M (step S214).

[0085] In the above process, the maintenance person M sends a DHCPv6 re-acquisition invitation to the DHCP server 40, which allows for flexible support of the interface set in the DHCP server 40. Furthermore, the information required when issuing an instruction is simple, consisting of only the target user's identifier, and can be handled manually. Furthermore, if the maintenance person M issues an instruction to the DHCP server 40 promptly, the time from issuing a switching execution instruction to completing switching of the user communication path can be achieved in a similar manner to the technology using the linked interface described in Non-Patent Document 1.

[0086] On the other hand, if the DHCP server 40 does not send a DHCPv6 re-acquisition prompt, the user terminals 30A to 30D can use the issuance of a DHCPv6 update by a timer as an opportunity to send a DHCPv6 update to the switching source edge router 20A and the switching destination edge router 20B for address re-acquisition. That is, although it takes longer to complete the switching, it is possible to avoid an increase in the work of the maintenance person M. Furthermore, the switching can be completed even if the maintenance person M misses out on performing the work.

[0087] (3-1-5. Setting deletion process) In order to delete the settings of users 1 to 4, the edge control device 10 deletes the user configuration 21 of user SO and the like held by the source edge router 20A (step S215). Here, the edge control device 10 is timed by a set timer and executes the processes from step S215 onwards. The timer is set to be longer than the T1 lease timer. The edge control device 10 also deletes the settings of the aggregation addresses ("#a1", "#b1") held by the source edge router 20A (step S217) and sets the aggregation addresses ("#a1", "#b1") in the destination edge router 20B (step S218). At this time, the maintenance person M can also check the progress of the setting deletion process with the edge control device 10 as necessary (step S216).

[0088] (3-1-6. Switching completion notification processing) When the setting deletion process is completed, the edge control device 10 transmits a switching completion notification to the maintenance person M who will perform the maintenance relocation (step S219), and ends the process.

[0089] (3-1-7. Other) In the example of Fig. 5, if the cooperation interface between the edge control device 10 and the DHCP server 40 was incompatible at the time of the switching execution instruction process, but is later changed to be compatible, the pseudo DHCP server cooperation process using the pseudo DHCP server 40V becomes unnecessary. That is, in the process of step S209 above, the edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the DHCP server 40, not to the pseudo DHCP server 40V. Also, the process of step S211 above becomes unnecessary. Also, in the process of step S214 above, the DHCP server 40 transmits a re-acquisition inducement completion notification to the edge control device 10, not to the maintenance person M.

[0090] [3-2. Flow of Edge Control Process 2] The flow of the edge control process 2 according to the first embodiment will be described in detail with reference to Fig. 6. Note that Fig. 6 uses an example of DHCPv6 as the communication method, but DHCPv4 or the like can also be used. In the example of Fig. 6, it is assumed that a linkage interface that can support some users (users 1 and 2) is introduced between the edge control device 10 and the DHCP server 40.

[0091] (3-2-1. Switching execution instruction processing) A maintenance technician M who performs the maintenance relocation transmits a switching execution instruction including switching information to the switching source edge router 20A that is performing user communication (step S301) with the user terminals 30 (30A, 30B, 30C, 30D) (step S302). Here, users 1 to 4 use user terminals 30A to 30D, respectively. User terminal 30A of user 1 and user terminal 30B of user 2 belong to VNE#a1, and user terminal 30C of user 3 and user terminal 30D of user 4 belong to VNE#b1. Note that "#a1" and "#b1" indicate aggregate addresses.

[0092] (3-2-2. DHCP blocking process) The edge control device 10 executes DHCP blocking processing (steps S303 to S308) to block DHCPv6 for users 1 to 4. Note that the processing of steps S303 to S308 is the same as the processing of steps S203 to S208 in the above-mentioned edge control processing 1, and therefore a description thereof will be omitted.

[0093] (3-2-3. IP switching process 1) In order to switch the IPv6 addresses of users 1 and 2, the edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the DHCP server 40, which has a compatible linkage interface installed (step S309). Next, the DHCP server 40 transmits a re-acquisition inducement to the user terminals 30A and 30B (step S310). Subsequently, the user terminals 30A and 30B transmit DHCPv6 updates to the source edge router 20A and the destination edge router 20B to re-acquire the addresses. At this time, the destination edge router 20B relays the DHCP packets, updates the DHCP binding table of the destination edge router 20B, and re-assigns the IP addresses, thereby completing the switching of the user communication path (step S311). Then, the DHCP server 40 transmits a re-acquisition inducement completion notification to the edge control device 10 (step S312).

[0094] As shown in the above process, the edge control device 10 can select a user and change the linkage method. The process of steps S309 to S312 enables IP switching to be completed in the same time as the edge control process shown in Non-Patent Document 1, in which a linkage interface is introduced. For example, the edge control device 10 can change the linkage method based on the user's characteristics, contracted service level, etc. Specifically, the edge control device 10 can shorten the time to complete switching by associating a high-grade user (e.g., a corporate line) with the DHCP server 40.

[0095] (3-2-4. Pseudo DHCP server linkage processing) The edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the dummy DHCP server 40V (step S313), and then receives the completion notification transmitted from the dummy DHCP server 40V (step S314).

[0096] (3-2-5. IP switching process 2) First, the maintenance person M transmits a DHCPv6 re-acquisition inducement instruction to the DHCP server 40 in order to switch the IPv6 addresses of users 3 and 4 (step S315). Next, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement to the user terminals 30C and 30D (step S316). Subsequently, the user terminals 30C and 30D transmit DHCPv6 updates to the source edge router 20A and the destination edge router 20B in order to re-acquire the addresses. At this time, the destination edge router 20B relays the DHCP packets, updates the DHCP binding table of the destination edge router 20B, and re-assigns the IP addresses, thereby completing the switching of the user communication path (step S317). Then, the DHCP server 40 transmits a re-acquisition inducement completion notification to the maintenance person M (step S318).

[0097] As shown in the above process, the edge control device 10 can select a user and change the collaboration method. In the process of steps S315 to S318, it is possible to complete IP switching in the same time as edge control process 1 in which a collaboration interface is not introduced.

[0098] (3-2-6. Setting deletion process) The edge control device 10 executes a setting deletion process (steps S319 to S322) to delete the settings of users 1 to 4. Note that the process of steps S319 to S322 is the same as the process of steps S215 to S218 in the above-described edge control process 1, and therefore a description thereof will be omitted.

[0099] (3-2-7. Switching completion notification processing) When the setting deletion process is completed, the edge control device 10 transmits a switching completion notification to the maintenance person M who will perform the maintenance relocation (step S323), and ends the process.

[0100] (3-2-8. Other) In the example of FIG. 6, there are three edge control processes for the switching time, which can be set as the service level for each user. The first process is a process in which, in cooperation with the DHCP server 40, an instruction is given to induce DHCPv6 re-acquisition. The second process is a process in which the maintenance person M gives an instruction to induce DHCPv6 re-acquisition after the pseudo DHCP server 40V responds. The third process is a process in which, after the pseudo DHCP server 40V responds, a voluntary DHCPv6 update is awaited. Also, in the example of FIG. 6, a case has been described in which only some users are targeted for collaboration, but collaboration can also be targeted by a unit such as a device or LAG.

[0101] [3-3. Flow of Edge Control Process 3] The flow of the edge control process 3 according to the first embodiment will be described in detail with reference to Fig. 7. Although Fig. 7 uses an example of DHCPv6 as the communication method, DHCPv4 or the like can also be used. In the example of Fig. 7, it is assumed that no linking interface is introduced between the edge control device 10 and the DHCP server 40, or that even if a linking interface is introduced, it is not compatible.

[0102] (3-3-1. Switching execution instruction processing) A maintenance technician M who performs the maintenance relocation transmits a switching execution instruction including switching information to the switching source edge router 20A that is performing user communication (step S401) with the user terminals 30 (30A, 30B, 30C, 30D) (step S402). Here, users 1 to 4 use user terminals 30A to 30D, respectively. User 1's user terminal 30A and user 2's user terminal 30B belong to VNE#a1, and user 30C of user 3 and user 4's user terminal 30D belong to VNE#b1. Note that "#a1" and "#b1" indicate aggregate addresses.

[0103] (3-3-2. DHCP blocking process) The edge control device 10 executes DHCP blocking processing (steps S403 to S408) to block DHCPv6 for users 1 to 4. Note that the processing of steps S403 to S408 is the same as the processing of steps S203 to S208 in the above-mentioned edge control processing 1, and therefore a description thereof will be omitted.

[0104] (3-3-3. IP switching process) First, the edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the dummy DHCP server 40V in order to switch the IPv6 addresses of users 1 to 4 (step S409). At this time, the dummy DHCP server 40V converts the received DHCPv6 re-acquisition inducement instruction into a format that matches the existing interface of the DHCP server 40 and transmits it to the DHCP server 40 (step S410). Next, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement to the user terminals 30A to 30D (step S411). Subsequently, the user terminals 30A to 30D transmit DHCPv6 updates to the source edge router 20A and the destination edge router 20B in order to re-acquire addresses. At this time, the destination edge router 20B relays the DHCP packets, updates the DHCP binding table of the destination edge router 20B, and re-assigns the IP addresses, thereby completing the switching of the user communication path (step S412). Then, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement completion notification to the dummy DHCP server 40V (step S413). At this time, the dummy DHCP server 40V converts the received DHCPv6 re-acquisition inducement completion notification into a format that matches the existing interface of the edge control device 10, and transmits it to the edge control device 10 (step S414).

[0105] As shown in the above process, the edge control device 10 can transmit the re-acquisition inducement instruction converted to be compatible via the pseudo DHCP server 40V to the DHCP server 40. Also, the edge control device 10 can receive the re-acquisition inducement completion notification converted to be compatible via the pseudo DHCP server 40V from the DHCP server 40.

[0106] (3-3-4. Setting deletion process) The edge control device 10 executes a setting deletion process (steps S415 to S418) to delete the settings of users 1 to 4. Note that the process of steps S415 to S418 is the same as the process of steps S215 to S218 in the edge control process 1 described above, and therefore a description thereof will be omitted.

[0107] (3-3-5. Switching completion notification process) When the setting deletion process is completed, the edge control device 10 transmits a switching completion notification to the maintenance person M who will perform the maintenance relocation (step S419), and ends the process.

[0108] (3-3-6. Other) 7, if the cooperation interface between the edge control device 10 and the DHCP server 40 was incompatible at the time of the switching execution instruction process, but is later changed to be compatible, the pseudo DHCP server cooperation process using the pseudo DHCP server 40V becomes unnecessary. That is, in the process of step S409 above, the edge control device 10 transmits a DHCPv6 re-acquisition inducement instruction to the DHCP server 40 without going through the pseudo DHCP server 40V. Also, in the process of step S413 above, the DHCP server 40 transmits a DHCPv6 re-acquisition inducement completion notification to the edge control device 10 without going through the pseudo DHCP server 40V.

[0109] 4. Effects of the First Embodiment Finally, the effects of the first embodiment will be described below: Effects 1 to 5 corresponding to the processing according to the first embodiment will be described below.

[0110] [4-1. Effect 1] In the first embodiment described above, switching information related to switching of the edge router accommodating the user terminal 30 is acquired, and when the switching information is acquired, the source edge router 20A is configured to block DHCP packets and cancel multicast communication, and when the blocking of DHCP packets and the cancellation of multicast communication are configured, user setting information is input to the destination edge router 20B, and based on the switching information, the quasi-DHCP server 40V, which is a virtual server, is instructed to induce the user terminal 30 to re-acquire an IP address, a notification is received from the quasi-DHCP server 40V that the instruction to induce re-acquisition of an IP address has been received, and when a predetermined time has elapsed since the notification that the instruction to induce re-acquisition of an IP address was received, the user setting information held by the source edge router 20A is deleted. Therefore, in the first embodiment, maintenance relocation of the edge router 20 can be performed effectively.

[0111] [4-2. Effect 2] In the first embodiment described above, when the edge router 20A is connected to the DHCP server 40, which is a physical server, via a predetermined interface in a manner that allows it to respond, it instructs the DHCP server 40 to induce re-acquisition of an IP address, receives a notification from the DHCP server 40 that the inducement for re-acquisition has been completed, and deletes the user setting information held by the switching source edge router 20A when it receives the notification that the inducement for re-acquisition has been completed. Therefore, in the first embodiment, when a linking interface is introduced, switching can be performed in a short time, and maintenance relocation of the edge router 20 can be performed effectively.

[0112] [4-3. Effect 3] In the first embodiment described above, an instruction to induce re-acquisition of an IP address is given for each predetermined unit at a predetermined time interval, and the instruction to induce re-acquisition is given to the DHCP server 40 for units that the DHCP server 40 can handle, and the instruction to induce re-acquisition is given to the dummy DHCP server 40V for units that the DHCP server 40 cannot handle. Therefore, in the first embodiment, it is possible to select cooperation with an interface for each predetermined unit, and maintenance relocation of the edge router 20 can be carried out effectively.

[0113] [4-4. Effect 4] In the first embodiment described above, an instruction to induce re-acquisition of an IP address converted into a compatible format by the pseudo DHCP server 40V is transmitted to the DHCP server 40, a notification is received from the DHCP server 40 that the inducement for re-acquisition of the IP address converted into a compatible format by the pseudo DHCP server 40V has been completed, and when the notification that the inducement for re-acquisition has been completed is received, the user setting information held by the switching source edge router 20A is deleted. Therefore, in the first embodiment, even if a cooperation interface is not introduced, maintenance relocation of the edge router 20 can be effectively performed using an existing interface.

[0114] [4-5. Effect 5] In the first embodiment described above, the trigger to reacquire an IP address is instructed for each device, LAG, or user. Therefore, in the first embodiment, the communication load can be reduced by limiting the communication target and communication time, and maintenance relocation of the edge router 20 can be effectively performed.

[0115] [System configuration, etc.] The components of each device shown in the drawings according to the above embodiments are conceptual functional units and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown, and all or part of each device can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc. Furthermore, all or any part of the processing functions performed by each device can be realized by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware using wired logic.

[0116] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using a known method.In addition, the information including the processing procedures, control procedures, specific names, various data and parameters shown in the above documents and drawings can be changed as desired unless otherwise specified.

[0117] 〔program〕 It is also possible to create a program written in a computer-executable language that executes the processes executed by the edge control device 10 described in the above embodiment. In this case, the same effects as those of the above embodiment can be obtained by having a computer execute the program. Furthermore, such a program may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read and executed by a computer to realize the same processes as those of the above embodiment.

[0118] 8 is a diagram showing a computer that executes a program. As shown in the example of FIG. 8, a computer 1000 includes, for example, a memory 1010, a CPU 1020, a hard disk drive interface 1030, a disk drive interface 1040, a serial port interface 1050, a video adapter 1060, and a network interface 1070, and these components are connected by a bus 1080.

[0119] As shown in FIG. 8, the memory 1010 includes a ROM (Read Only Memory) 1011 and a RAM 1012. The ROM 1011 stores a boot program such as a BIOS (Basic Input Output System). The hard disk drive interface 1030 is connected to a hard disk drive 1090 as shown in FIG. 8. The disk drive interface 1040 is connected to a disk drive 1100 as shown in FIG. 8. A removable storage medium such as a magnetic disk or an optical disk is inserted into the disk drive 1100. The serial port interface 1050 is connected to a mouse 1110 and a keyboard 1120 as shown in FIG. 8. The video adapter 1060 is connected to a display 1130 as shown in FIG. 8.

[0120] 8, the hard disk drive 1090 stores, for example, an OS 1091, an application program 1092, a program module 1093, and program data 1094. That is, the above programs are stored, for example, on the hard disk drive 1090 as program modules in which instructions to be executed by the computer 1000 are written.

[0121] The various data described in the above embodiment are stored as program data, for example, in the memory 1010 or the hard disk drive 1090. The CPU 1020 then reads the program module 1093 and the program data 1094 stored in the memory 1010 or the hard disk drive 1090 into the RAM 1012 as needed, and executes various processing procedures.

[0122] Note that the program module 1093 and program data 1094 related to the program are not limited to being stored in the hard disk drive 1090, and may be stored in, for example, a removable storage medium and read by the CPU 1020 via a disk drive or the like. Alternatively, the program module 1093 and program data 1094 related to the program may be stored in another computer connected via a network (such as a LAN (Local Area Network) or WAN (Wide Area Network)) and read by the CPU 1020 via the network interface 1070.

[0123] The above-described embodiments and their modifications are included in the technology disclosed in this application, as well as in the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0124] 10 Edge control device (communication control device) 11 Input section 12 Output section 13 Communications Department 14 Storage section 15 Control Unit 151 Edge control section 151a Acquisition Department 151b Setting section 151c Input section 151d Instruction section 151e Reception 151f Deleted section 152 Pseudo server control unit 152a Construction Department 20, 20A, 20B Edge Router 21 User configuration information (user configuration) 30, 30A, 30B, 30C, 30D User terminal 40 DHCP Server 40V pseudo DHCP server 50, 50A, 50B User DB 60, 60A, 60B communication network 100 Edge Control System

Claims

1. an acquisition unit that acquires switching information regarding switching of an edge router that accommodates a user terminal; a setting unit that, when the acquisition unit acquires the switching information, sets the switching source edge router to block DHCP (Dynamic Host Configuration Protocol) packets and cancel multicast communication; an input unit that inputs the user's setting information to a switching destination edge router when the setting unit sets blocking of the DHCP packets and cancellation of the multicast communication; an instruction unit that instructs a pseudo DHCP server, which is a virtual server, to induce the terminal to reacquire an IP (Internet Protocol) address based on the switching information; a reception unit that receives a notification from the pseudo DHCP server that the instruction to induce re-acquisition has been received; a deletion unit that deletes the user's configuration information held by the switching source edge router when a predetermined time has elapsed since the notification of receipt of the instruction to induce re-acquisition is received; A communication control device comprising:

2. The instruction unit If the device is connected to a DHCP server, which is a physical server, via a predetermined interface, the device instructs the DHCP server to trigger the re-acquisition of the DHCP server. The reception unit receiving a notification from the DHCP server that the re-acquisition has been initiated; The deletion unit When receiving a notification that the trigger for re-acquisition has been completed, the switching source edge router deletes the user's setting information held by the switching source edge router.

2. The communication control device according to claim 1.

3. The instruction unit Instructing the trigger for reacquisition at predetermined time intervals for each predetermined unit; Instructing the DHCP server to induce the reacquisition for the unit that the DHCP server can handle; For the unit that the DHCP server cannot handle, the pseudo DHCP server is instructed to induce reacquisition.

3. The communication control device according to claim 2.

4. The instruction unit Sending to a DHCP server the instruction to induce re-acquisition, which has been converted into a format that can be handled by the pseudo DHCP server; The reception unit receiving a notification from the DHCP server that the re-acquisition inducement has been completed and converted into a format that can be handled by the pseudo DHCP server; The deletion unit When receiving a notification that the trigger for re-acquisition has been completed, the switching source edge router deletes the user's setting information held by the switching source edge router.

2. The communication control device according to claim 1.

5. The instruction unit The triggering of the reacquisition is instructed for each device, LAG (Link Aggregation Group), or user.

5. The communication control device according to claim 1, wherein the communication control device is a communication control device.

6. A communication control method executed by a communication control device, an acquisition step of acquiring switching information regarding switching of an edge router accommodating a user terminal; a setting step of setting the switching source edge router to block DHCP packets and cancel multicast communication when the switching information is acquired in the acquisition step; an input step of inputting the user's setting information to a switching destination edge router when the setting step sets blocking of the DHCP packet and cancellation of the multicast communication; an instruction step of instructing a pseudo DHCP server, which is a virtual server, to induce the terminal to reacquire an IP address based on the switching information; a receiving step of receiving a predetermined notification based on the instruction to induce re-acquisition from the pseudo DHCP server; a deletion step of deleting the user's setting information held by the switching source edge router when a predetermined time has elapsed since the notification of receipt of the instruction to induce re-acquisition has been received; A communication control method comprising:

7. an acquisition procedure for acquiring switching information regarding switching of an edge router accommodating a user terminal; a setting procedure for setting the switching source edge router to block DHCP packets and cancel multicast communication when the switching information is acquired in the acquisition procedure; an input procedure for inputting the user's setting information to a switching destination edge router when the setting procedure sets blocking of the DHCP packet and cancellation of the multicast communication; an instruction procedure for instructing a pseudo DHCP server, which is a virtual server, to induce the terminal to reacquire an IP address based on the switching information; a receiving procedure for receiving a predetermined notification based on the instruction to induce re-acquisition from the pseudo DHCP server; a deletion procedure for deleting the user's configuration information held by the switching source edge router when a predetermined time has elapsed since the notification of receipt of the instruction to induce re-acquisition has been received; A communication control program that causes a computer to execute the above.

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