JP4126859B2 - Response method, network system, and terminal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a response method, a network system, and a terminal device.
[0002]
[Prior art]
In recent years, a plurality of terminal devices such as printers, copiers, computers, and other OA devices are often used connected to a network. Each terminal device connected to the network work is assigned an address on the network, and each terminal device is uniquely identified by the assigned address. The user can access each terminal device according to the address.
[0003]
When the terminal device is relocated and reconnected to another network, a new address is assigned. In this case, even if the user accesses the address before the relocation, the user cannot communicate with the relocated terminal device. Therefore, when the terminal device is relocated, the system administrator needs to notify all users who wish to communicate with the relocated terminal device of the relocated address by a document or the like. In all terminal devices, it is necessary to re-register the relocated address of the relocated terminal.
[0004]
In order to solve this problem, there are methods using a server for a name service and a server for a directory service. These servers store a correspondence table (record) in which names of terminal devices to be managed and addresses assigned to the terminal devices are registered. When a certain device inquires about the address of the terminal device, these servers search for the record held and send back the corresponding address.
[0005]
For example, a packet transfer technique for managing addresses using a server is described in Japanese Patent Laid-Open No. 5-83260. According to the packet transfer technique described in this publication, a server for managing addresses is provided, and the change history of all addresses is managed by this server.
[0006]
[Problems to be solved by the invention]
However, according to the packet transfer technique described in the above publication, the administrator must register the relocation information in a dedicated server each time the terminal device is relocated.
[0007]
Also, according to the packet transfer technique described in the above publication, one dedicated server acts as a proxy for all the relocated terminal devices. Therefore, when a problem occurs in this dedicated server, proxy processing according to access in place of the relocated terminal device, for example, data transfer processing to a new address after relocation is interrupted.
[0008]
The present invention has been made to solve such a problem, and a first object of the present invention is to provide a response method and a network that can reduce the burden of registration when a terminal device is moved to another network. A system and a terminal device are provided.
[0009]
The second object of the present invention is to prevent the occurrence of a situation in which all proxy processing according to access is interrupted on behalf of a relocated terminal device when a failure occurs in one device. A response method, a network system, and a terminal device are provided.
[0010]
[Means for Solving the Problems]
The object of the present invention is achieved by the following configurations.
[0011]
(1) In the response method according to the present invention, when one terminal device is relocated from the own network to which a plurality of terminal devices are connected to another network, the address before relocation is represented on behalf of the relocated terminal device. To respond to access to The relocated terminal device transmits a packet including the relocated address to the own network, and a plurality of terminal devices connected to the own network receive the packet, thereby The step of acquiring an address, and each terminal device that has received the packet, when the proxy of the relocated terminal device is possible, indicates to the other terminal device connected to the local network that the proxy is to be performed And a step of selecting a terminal device in charge of the proxy of the relocated terminal device based on a notification of performing the proxy from a plurality of terminal devices that have received the packet. It is characterized by that.
[0012]
(2) When an address before the relocation of the relocated terminal device is accessed, the terminal device in charge of the relocated terminal device provides the access source with the relocated address of the relocated terminal device. To notify.
[0013]
(3) When an address before relocation of the relocated terminal device is accessed, the terminal device in charge of the relocated terminal device transfers data to the address after relocation of the relocated terminal device To do.
[0014]
(4) The terminal device in charge of the transferred terminal device acts as a proxy for a predetermined number of terminal devices or less.
[0017]
( 5 When the priority regarding proxy is higher than that of the notification source terminal device, the terminal device that has received the notification to perform proxy instructs the notification source terminal device not to perform proxy.
[0018]
( 6 The terminal device that has received the notification that the proxy is to be performed does not perform the proxy when the priority regarding the proxy is lower than the notification source terminal device.
[0019]
( 7 ) The priority regarding proxy is set according to the period during which the terminal device is continuously connected to the network.
[0020]
( 8 In the network system according to the present invention, when one terminal device is relocated from the own network to which a plurality of terminal devices are connected to another network, access to the address before relocation is made on behalf of the relocated terminal device A network system that complies with The relocated terminal device transmits a packet including the relocated address to the own network, and a plurality of terminal devices connected to the own network receive the packet, thereby determining the relocated address. Each terminal device that has acquired and received the packet notifies the other terminal devices connected to the local network that proxying is possible when the transferred terminal device can be substituted, The terminal device in charge of the relocated terminal device, from among the plurality of terminal devices that received the packet, Selected based on the notice to perform the proxy, It is characterized by that.
[0021]
( 9 The terminal device according to the present invention is Transfer On behalf of other installed terminal devices Other terminal devices A terminal device having response means for responding to access to an address before relocation, When the terminal device itself is relocated from its own network to another network, a plurality of other terminal devices connected to the own network are transmitted by transmitting packets including the relocated address to the own network. By receiving the packet, the plurality of other terminal devices acquire the address after the relocation, and the other terminal device connected to the own network to which the terminal device is connected is relocated to another network. In the case of being transferred, a packet including the relocated address of the relocated terminal device is received from the relocated terminal device, and the relocated address of the relocated terminal device is obtained and relocated. If proxying of the terminal device is possible, it notifies the other terminal devices connected to the local network that proxying is to be performed, and Which terminal device selects whether to charge a proxy between the location and the other terminal devices It is characterized by that.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0023]
FIG. 1 is a block diagram showing the overall configuration of a network system according to the present invention.
[0024]
The network system has a plurality of networks 100, 200, and 300. Each network 100, 200, 300 is a local network (LAN). In FIG. 1, each network 100, 200, 300 is connected via the Internet 400. However, unlike the present embodiment, the networks 100, 200, 300 may be directly connected via a router (not shown).
[0025]
A terminal device is connected to each network 100, 200, 300. As illustrated in FIG. 1, terminal devices 120 a and 120 b are connected to the network 100, terminal devices 220 a and 220 b are connected to the network 200, and terminal devices 320 a and 320 b are connected to the network 300. Yes. The number of terminal devices connected to each network 100, 200, 300 is not limited to the number shown in FIG.
[0026]
The terminal device 220b shown in FIG. 1 has been moved from the network 100 to the network 200. As a result of the relocation of the terminal device 220b, the address assigned to the terminal device 220b is changed from the address “1.2.0.2” before relocation to the address “1.3.0.2” after relocation. In addition, the address in this embodiment is an IP address, for example.
[0027]
Therefore, for example, when the terminal device 320a desires to access the terminal device 220b, the terminal device 320a may access the address “1.2.0.2” before the relocation of the terminal device 220b. Cannot communicate with 220b. In order to communicate with the terminal device 220b, the terminal device 320a needs to access the address “1.3.0.2” after the relocation of the terminal device 220b.
[0028]
According to the network system of the present invention, the relocated terminal device 220b transmits a post-relocation address notification to the entire network 100 connected before the relocation. The terminal responding to the address “1.2.0.2” before relocation on behalf of the relocated terminal device 220b among the plurality of terminal devices 120a and 120b connected to the network 100 that has received this relocation notification A device is appropriately selected. For example, the terminal device 120a is selected as a terminal device acting as a proxy for the transferred terminal device 220b. When the selected terminal device 120a accesses the address before the relocation of the relocated terminal device 220b, the new address “1.3.0 after the relocation of the terminal device 220b is transferred to the access source. .2 ". Alternatively, the selected terminal device 120a performs data transfer to the new address “1.3.0.2” after the relocation.
[0029]
Although FIG. 1 illustrates the case where the terminal device 220b is relocated from the network 100 to the network 200 and the terminal device 320a accesses the address before relocation of the terminal 220b, the present invention is limited to this case. I can't. The terminal device to be relocated and the terminal device that accesses the address before relocation of the relocated terminal device may be any terminal device.
[0030]
FIG. 2 is a block diagram illustrating an internal configuration of the terminal device.
[0031]
According to the present embodiment, the terminal devices 120a, 120b, 220a, 220b, 320a, and 320b have a common configuration. In FIG. 2, the internal configuration of the terminal device 220b will be described as an example.
[0032]
The CPU 221 controls the entire terminal device 220b. The nonvolatile RAM 222 stores various data indicating the presence of other terminal devices and the addresses of the terminal devices as a table. The RAM 223 temporarily stores data. The ROM 224 stores a control program.
[0033]
The time management unit 225 includes a timer. The time management unit 225 manages, for example, the remaining time of a period during which proxy processing of the transferred terminal device is performed.
[0034]
The network interface 226 is an interface for communicating with other terminal devices.
[0035]
The presence list management unit 227 mutually confirms the presence of terminal devices on the network via the network interface 226, and manages presence information as a presence list based on the confirmation result.
[0036]
The proxy response execution unit 228 acts on behalf of the relocated terminal device to access the address before relocation. In addition, if another terminal device is trying to act as a proxy for a terminal device that is already in charge of the proxy, an objection is made to instruct the other terminal device not to act as a proxy. Notice.
[0037]
The post-relocation address notification unit 229 monitors whether or not the own device itself, that is, the terminal device 220b has been relocated, and if the own device is relocated, the network to which the own device was connected before relocation, that is, the network The new address after the relocation is notified to all 100.
[0038]
The time management unit 225, the presence list management unit 227, the proxy response execution unit 228, and the post-relocation address notification unit 229 can also be realized as software executed by the CPU 221, using a dedicated logic IC or the like. It can also be configured as hardware.
[0039]
The network system configured as described above functions as follows.
[0040]
FIG. 3 is a main flowchart showing the overall processing of each terminal device. The content of the flowchart shown in FIG. 3 is stored as a control program in a memory such as the ROM 224 of each terminal device, and is executed by the CPU 221 or the dedicated IC that operates in cooperation with the CPU 221.
[0041]
First, in step S100, it is determined whether or not the device itself has been moved.
[0042]
If the device itself has been relocated (S100: YES), the process of step S200 is performed, and if it has not been relocated (S100: NO), the processes of steps S300 to S900 are performed.
[0043]
For example, as illustrated in FIG. 1, the terminal device 220b moved from the network 100 to the network 200 performs the process of step S200. On the other hand, a terminal device that has not been relocated, such as the terminal device 120a, performs the processing from step S300.
[0044]
In step S200, the new address after the relocation is notified to the network (local network) to which the own device was connected before the relocation.
[0045]
In step S300, the existence list update process is performed.
[0046]
In step S400, it is determined whether a notification of the post-relocation address transmitted from the relocated terminal device, for example, the terminal device 220b, has been received. When the notification of the address after relocation is received, the process of step S500 is performed. On the other hand, if the post-relocation address notification is not received, the process of step S900 is performed.
[0047]
In step S500, a transition process to the proxy mode is performed as a process when the notification of the address after the relocation is received. The proxy mode is a mode for performing processing according to the address before relocation on behalf of the relocated terminal device. When shifting to the proxy mode, the fact that proxy is performed (hereinafter referred to as “proxy processing declaration”) is notified to other terminal devices.
[0048]
In step S600, it is determined whether a proxy processing declaration notification has been received from another terminal device. When the notification of the proxy processing declaration is received from another terminal device for the terminal device that the device itself intends to take charge of (step S600: YES), the processing of step S700 is performed. On the other hand, when the notification of the proxy process declaration has not been received from another terminal device (step S600: NO), the process of step 800 is performed.
[0049]
In step S700, objection notification processing for instructing other terminal devices not to act is performed.
[0050]
In step S800, when the terminal device selected as the terminal device acting as the proxy for the relocated terminal device has accessed the address before relocation of the relocated terminal device, a new one after relocation to the access source is obtained. Proxy processing is performed in which the address is notified and data is transferred to the new address after the transfer.
[0051]
In step S900, processing such as deletion of unnecessary elements registered in the existence list is performed, and the process returns to step S100.
[0052]
The above processing will be described with reference to the specific example shown in FIG.
[0053]
First, when the terminal device 220b is moved from the network 100 to the other network 200, the terminal device 220b notifies the entire network 100 connected before the transfer of the new address after the transfer. This post-relocation address notification is received within the network 100.
[0054]
A terminal device acting as a proxy for the relocated terminal device 220b is selected from the plurality of terminal devices 120a and 120b connected to the network 100. As will be described later, the terminal device acting as the transferred terminal device 220b is determined by the priority determined in accordance with the high reliability or the like.
[0055]
For example, when the terminal device 120a is selected as the terminal device in charge of the terminal device 220, the terminal device 120a acts as the proxy for the terminal device 220b and the address “1.2.0 before the terminal device 220b is moved. .2 ”.
[0056]
Details of each process will be described below.
[0057]
First, processing when the own device itself is moved will be described.
[0058]
FIG. 4 is a flowchart showing the contents of the post-relocation address notification process by the relocated terminal apparatus, and shows the process contents performed by the terminal apparatus 220b in FIG. 1, for example. FIG. 4 shows the details of the processing in step S200 of FIG.
[0059]
In step S201, the post-relocation address of the own device is acquired. Each terminal device 120a, 120b, 220a, 220b, 320a, 320b monitors the setting state of its own address, and detects that its own address has been changed. For example, the terminal device 220b detects that its own address has been changed from “1.2.0.2” to “1.3.0.2”, and the relocated address “1.3.0.2”. Is obtained.
[0060]
In step S202, it is determined whether the own apparatus has been moved to another network. In other words, it is determined whether relocation has been performed within one network or relocation among a plurality of networks. This determination is made based on, for example, whether or not the network address part included in the address acquired in step S201 has changed. The network address part is an address part set for each network.
[0061]
When it is determined that the device itself has not been moved to another network (S202: NO), a return is made, and when it is determined that the device has been moved to another network (S202: YES), The process of step S203 is performed. It should be noted that the own device that is determined to have been relocated within one network can complete the setting by acquiring an address using a normal name server or the like. In this case, an address is automatically acquired based on DHCP (Dynamic Configuration Protocol).
[0062]
In step S203, the post-relocation address and the terminal-specific information are notified to the network to which the own device was connected before the relocation. The network connected before the relocation is specified according to the address before relocation stored in the nonvolatile RAM 222, in particular, the network address portion.
[0063]
More specifically, the post-relocation address and terminal specific information are notified by transmitting a post-relocation address notification packet 500 shown in FIG. 5 to the network connected before the relocation. A broadcast packet or a multicast packet is used as the post-relocation address notification packet 500 so that a plurality of terminal devices in the network connected before the relocation can receive the packet. According to the broadcast packet communication, one message can be transmitted to all devices in a specific range of the network. For example, in the case of IP (Internet Protocol), broadcast packet transmission can be instructed by setting all bits of addresses other than the network address portion to 1.
[0064]
The post-relocation address notification packet 500 includes a post-relocation address 501, a pre-relocation address 502, terminal specific information 503, and a header portion not shown.
[0065]
Here, the terminal-specific information 503 is an address that can uniquely identify each terminal device. For example, the terminal specific information 503 is a MAC address (media access control address). Here, the MAC address is an address determined for each device connected to the IEEE 802.3 standard LAN. As the terminal unique information 503, identification information combining each terminal device name and a product serial number may be used.
[0066]
In step S204, it is determined whether a proxy process start notification has been received. As described later, the proxy process start notification is a notification transmitted from the terminal device selected as the terminal device in charge of proxy in response to the start of the proxy process. When the proxy process start notification is received (step S204: YES), the process returns as it is. On the other hand, when the proxy process start notification is not received even after a certain time (step S204: NO), the process of step S205 is performed.
[0067]
In step S205, it is determined whether or not the post-relocation address notification packet 500 has been transmitted a specified number of times. When the number of transmissions of the post-relocation address communication packet 500 is less than the specified number (S205: NO), the process returns to step S203, and the post-relocation address notification packet 500 is transmitted again and the transmission is performed more than the specified number of times. (S205: YES), a return is made.
[0068]
If the proxy processing start notification is not received even after sending the address notification packet 500 after relocation for a specified number of times, a process is performed to display on the display that the proxy processing start is not confirmed, and the user is notified. You can also.
[0069]
As described above, each terminal device in the present embodiment detects that it has moved, and transmits the post-relocation address notification packet 500 in the broadcast mode to the network connected before the relocation. As a result, the relocated address is distributed and managed in a plurality of terminal devices currently connected to the network connected before the relocation.
[0070]
Next, processing on the side of receiving the post-relocation address notification packet from the transferred terminal device will be described with reference to FIGS. The processing shown below is, for example, the processing content performed by the terminal devices 120a and 120b that receive the post-relocation address notification packet from the terminal device 220b in FIG.
[0071]
FIG. 6 is a flowchart showing the contents of the existence list update process. FIG. 6 shows the details of the processing in step S300 of FIG.
[0072]
In step S301, presence information indicating the presence (connection state) of the terminal device in the same network is received. Each terminal device connected to the same network communicates presence information with each other and confirms the presence of each other. For example, the terminal devices 120a and 120b connected to the network 100 communicate presence information with each other.
[0073]
More specifically, communication of presence information between the terminal devices in each network 100, 200, 300 is performed by transmitting a terminal presence information packet within each network.
[0074]
A broadcast packet or a multicast packet is used as the terminal presence information packet. Therefore, the terminal presence information packet is transmitted only within a specific network and is not transmitted to an external network. In addition, since broadcast packets are used, the number of receiving terminals is not limited to one, and a plurality of terminal devices in the local area network can simultaneously receive one packet. For example, the terminal device 120 a illustrated in FIG. 1 transmits a terminal presence information packet only within the network 100. Therefore, the terminal presence packet transmitted by the terminal device 120a is not transmitted to the networks 200 and 300.
[0075]
FIG. 7 shows a terminal presence information packet.
[0076]
Terminal presence information packet 600 includes terminal specific information 601, current address 602, priority 603, and a header portion not shown.
[0077]
Here, the terminal unique information 601 is the same MAC address as the terminal unique information 503. The current address 602 is the current IP address.
[0078]
The priority 603 is a parameter serving as a reference when a terminal device acting as a proxy for the relocated terminal device is selected from a plurality of terminal devices, and is set for each terminal device. According to this embodiment, when a terminal device is transferred, proxy processing is performed by the terminal device in the network to which the transferred terminal device was connected before the transfer. In this case, when a plurality of terminal devices can act as a proxy, the terminal device set with a higher priority 603 takes charge of the proxy.
[0079]
The terminal device selected as the terminal device in charge of the proxy is desirably a highly reliable terminal device that is connected to the network without being relocated for a long period of time. For this reason, the priority 603 increases the reliability by increasing the continuous operation time, which is the time during which the terminal device is continuously connected to the networks 100, 200, 300, or the operation time at a certain address. High depending on
[0080]
In step S302, it is determined whether or not the terminal device whose presence has been confirmed is already registered in the presence list. The presence of the terminal device is confirmed by receiving the terminal presence information packet 600. If this terminal device is not registered in the existence list (step S302: NO), the process of step S303 is performed, and if already registered (step S303: YES), the process of step S304 is performed. It is.
[0081]
Here, FIG. 8 shows an example of the existence list.
[0082]
The presence list 700 is a table created in each terminal device based on the received terminal presence information packet 600. The created presence list 700 is stored in the nonvolatile RAM 222. In addition, the presence list 700 is managed and updated by the presence list management unit 227.
[0083]
The existence list 700 includes terminal specific information 701, current address 702, priority 703, remaining time 704, and transfer destination address 705.
[0084]
The terminal unique information 701, the current address 702, and the priority 703 are obtained by organizing the terminal unique information 601, the current address 602, and the priority 603 included in the received terminal presence information packet 600 as a table.
[0085]
The remaining time 704 is the remaining time until the information for each terminal device that is an element of the presence list is deleted from the presence list 700. The remaining time 704 is managed based on the time management unit 225. Therefore, even if the terminal device is once registered in the presence table 700, and the presence is not confirmed by the terminal presence packet 600 thereafter, the registration is sequentially deleted as an unnecessary element. As a result, a presence list reflecting the connection status of the terminal device to the latest network is created.
[0086]
The transfer destination address 705 is registered based on the post-transfer address 501 of the post-transfer address notification packet 500 described above. For example, in FIG. 8, “1.3.0.2” is registered as the transfer destination address 705 in the terminal device 220b whose terminal-specific information is “12345672”.
[0087]
In step S303 in FIG. 6, the terminal unique information 701, the current address 702, the priority 703, and the remaining time 704 of the terminal device that has been newly confirmed are newly registered in the existence list 700.
[0088]
In step S304, as a process when the presence of the terminal device already registered in the presence list 700 is confirmed by receiving the terminal presence information packet 600, the transfer destination address 705 corresponding to the corresponding terminal device is included in the presence list 700. It is determined whether or not is registered. If the transfer destination address 705 is not registered (S304: NO), the process of step S306 is performed. If the transfer destination address 705 is registered (S304: YES), the process of step S305 is performed. It is.
[0089]
In step S305, the corresponding transfer destination address is deleted. Specifically, when the terminal device that has been relocated to another network returns again to the network before relocation within a predetermined period, the process of step S305 is performed. When the relocated terminal device returns to the network before relocation, it is determined that it is no longer necessary for another device to perform proxy processing. Therefore, the transfer destination address 705 becomes unnecessary and is deleted.
[0090]
In step S306, the value of the priority 703 is updated based on the continuous operation time or the operation time at a certain address.
[0091]
As described above, a plurality of terminal devices connected to the same network perform broadcast packet communication with each other. Therefore, a plurality of terminal devices can individually hold similar presence lists. As a result, the connection state and address of the terminal device in each network are managed in a distributed manner by a plurality of terminal devices.
[0092]
FIG. 9 is a flowchart showing the contents of the transition process to the proxy mode. FIG. 9 shows details of the processing in step S500 of FIG.
[0093]
In step S501, the post-relocation address notification packet 500 transmitted from the relocated terminal device is received to obtain the post-relocation address.
[0094]
In step S502, based on post-relocation address notification packet 500, the pre-relocation address and terminal-specific information of the relocated terminal device are acquired.
[0095]
For example, the terminal devices 120a and 120b shown in FIG. 1 receive the post-relocation address notification packet 500 transmitted by the relocated terminal device 220b, thereby moving the post-relocation address “1.3.0.2”. The previous address “1.2.0.2” and the terminal specific information “12345672” are acquired.
[0096]
In step S503, it is determined whether or not the terminal device identified by the terminal specific information 501 included in the post-relocation address notification packet 500 is registered in the existence list 700. If the identified terminal device is not registered in the presence list 700 (step S503: NO), a return is made, and if it is registered in the presence list 700, the process of step S504 is performed. Note that when the terminal device is not registered in the existence list 700, the remaining time 704 is lost after the terminal device is once registered, and it is deleted.
[0097]
In step S504, it is determined whether or not the transfer destination address 705 is registered for the terminal device identified by the terminal unique information 501. If the transfer destination address 705 is registered (step S504: YES), the process of step S505 is performed. If the transfer destination address 705 is not registered (step S504: NO), the process of step 506 is performed. It is.
[0098]
In step S505, the proxy address corresponding to the corresponding transfer destination address is deleted. Specifically, once the terminal device that has been transferred to another network and is acting as a proxy is transferred to another network or the like, the process of step S505 is performed. That is, when the proxy terminal device is relocated to another network, it is necessary to update the proxy address corresponding to the transfer destination address of the terminal device. The proxy address corresponding to is deleted.
[0099]
In step S506, it is determined whether or not it is possible to shift to the proxy mode. In the present embodiment, the maximum number that one terminal device can take charge of is limited in advance. When one terminal device is allowed to act as a proxy for many terminal devices, a failure occurs in this one terminal device, so that many proxy processes, for example, data transfer to a transfer destination address, are performed. The problem of being unable to execute occurs. In this embodiment, the occurrence of this problem can be fundamentally prevented by limiting the number of terminal devices that one terminal device can serve as a proxy. This is different from the conventional technology in which all terminal devices are substituted by one proxy server (proxy server). The maximum number that one terminal device can act as a proxy is set in advance by the administrator.
[0100]
If the transition to the proxy mode is impossible (step S506: NO), a return is made. If the transition to the proxy mode is possible (step S506: YES), the process of step S507 is performed.
[0101]
In step S507, the proxy processing declaration is notified to other terminal devices connected to the same network. As a result, the terminal device capable of acting as a proxy can notify other terminal devices in advance that the proxy will be performed before actually starting the proxy of the transferred terminal device. More specifically, the notification of the proxy processing declaration is performed by transmitting the proxy processing declaration packet 800 shown in FIG. 10 to the entire network to which the transferred terminal device was connected before the transfer. Preferably, the proxy processing declaration packet 800 is a broadcast packet or a multicast packet whose reception destination is indefinite.
[0102]
The proxy processing declaration packet 800 includes terminal specific information 801 of the terminal device to be proxyed, that is, the terminal specific information 802 of the terminal device in charge of the proxy of the transferred terminal device, and the transferred terminal device. The priority 803 of the terminal device in charge of the proxy is included.
[0103]
The terminal specific information 801 and 802 are the same as the terminal specific information 701 registered in the presence list 700 and the terminal specific information 601 included in the terminal presence information packet 600. The terminal device priority 803 is the same as the priority 703 registered in the presence list 700 and the priority 603 included in the terminal presence information packet 600.
[0104]
In step S508, after the proxy processing declaration packet 800 is transmitted in step S507, it is determined whether or not an objection notification is received from another terminal device. If there is an objection from another terminal device within a certain period (step S508: YES), a return is made without starting the proxy process. On the other hand, when there is no objection from another terminal device within a certain period (step S508: NO), the process of step S509 is executed.
[0105]
In the example shown in FIG. 1, the relocated terminal device 220b transmits the relocated address notification packet 500 to the network 100 to which the relocated terminal device 220b was connected before relocation. Therefore, a plurality of terminal devices 120a and 120b connected to the network 100 can be in charge of the proxy. In this case, for example, the terminal device 120a transmits a proxy processing declaration packet 800. The other terminal device 120b that has received the proxy processing declaration packet 800 refers to the priority level 803 included in the proxy declaration packet 800, and the priority level of the local device is higher than the priority level 803 included in the received proxy declaration packet 800. If 703 is high, the objection is notified to the terminal device 120a that is the transmission source of the proxy processing declaration packet 800. Therefore, when the terminal device 120a receives the objection notification, the terminal device 120b, which is the objection notification source, does the proxy processing without starting the proxy process.
[0106]
A plurality of terminal devices 120a and 120b may also transmit the proxy processing declaration packet 800 to each other. In this case, the terminal device that has transmitted the proxy processing declaration packet 800 having the higher priority 803 starts the proxy processing. That is, when a terminal processing declaration packet 800 having a higher priority 803 than the proxy processing declaration packet 800 transmitted by itself is received from another terminal device, the terminal apparatus stops the processing without performing a proxy. In other words, the proxy processing declaration packet having a higher priority than the proxy processing declaration packet transmitted by itself functions in the same manner as the objection notification described above.
[0107]
In step S509, the post-relocation address acquired by the post-relocation address notification 500 is registered as a proxy address that functions as the transfer destination address 705.
[0108]
In step S510, proxy processing is started, and proxy processing start notification is transmitted to the relocated terminal device.
[0109]
FIG. 11 is a flowchart showing the content of the objection notification process. FIG. 11 shows the details of the processing in step S700 of FIG.
[0110]
In step S701, the proxy processing declaration packet 800 transmitted by another terminal device is received. For example, the proxy processing declaration packet 800 is transmitted into the network 100 by the terminal device 120b shown in FIG. As a result, the proxy processing declaration packet 800 is received by the terminal device 120a.
[0111]
In step S702, the terminal specific information 801 of the device to be represented is confirmed. The confirmation is performed by referring to the contents of the proxy processing declaration packet 800. For example, the terminal device 120a confirms the terminal unique information “1234572” of the terminal device 220b to be proxyed based on the proxy processing declaration packet 800 from the terminal device 120b.
[0112]
In step S703, it is determined whether a proxy address that functions as the transfer destination address 705 for the terminal specific information is registered. When the proxy address is not registered (step S703: NO), the process returns as it is, and when it is registered (step S703: YES), the process of step S704 is performed.
[0113]
In step S704, for the terminal device for which the proxy address has already been registered and for which the self is responsible, the notification source of the proxy declaration packet 800 is processed as processing when the proxy processing declaration packet 800 transmitted by another terminal device is received. The objection is notified to the terminal device. The objection notification is similar to the proxy processing declaration packet 800 shown in FIG. 10, the terminal specific information 801 of the terminal device to be proxyed, the terminal specific information 802 of the terminal device in charge of the proxy of the transferred terminal device, and The priority 803 of the terminal device in charge of the proxy of the transferred terminal device is included. However, in the case of an objection notification, since the recipient is determined, the objection can be notified by a unicast packet instead of a broadcast packet.
[0114]
The case where the terminal device 120a shown in FIG. 1 is already in charge of the proxy of the terminal device 220b will be described as an example. When the other terminal device 120b transmits the proxy processing declaration packet 800 related to the terminal device 220b, The terminal device 120a that has received the proxy processing declaration packet 800 notifies the terminal device 120b of an objection to instruct not to perform proxying.
[0115]
In addition, in FIG. 11, although the proxy address has already been registered and the terminal device for which the self is in charge is described, the processing when the proxy processing declaration packet 800 transmitted by another terminal device is received has been described. The present invention is not limited to this case. For example, when the proxy processing declaration packet 800 is received from another terminal device, it is possible to determine whether or not to notify the objection based on the priority comparison regardless of whether or not the proxy address is registered.
[0116]
Also in this case, it is first determined whether or not the own device can proxy the terminal device to be proxyed. As a result of the determination, if the proxy is possible, the priority 703 of the own device is compared with the priority 803 of another terminal device acquired based on the proxy processing declaration packet 800. As a result of the comparison, when the self-priority is higher than the terminal device that is the transmission source of the proxy processing declaration packet 800, an objection is notified.
[0117]
As described above, according to the processing shown in FIGS. 9 and 11, the terminal device acting as the transferred terminal device is selected from the plurality of terminal devices that have received the post-relocation address notification packet 500. A plurality of terminal devices capable of proxying each other transmits a proxy processing declaration packet 800, and a terminal device to be proxyed is selected by comparing which priority is higher. Alternatively, when a terminal device with a low priority transmits a proxy processing declaration packet, the terminal device with a higher priority can make an objection notification. The terminal device that performs the proxy can also be selected by combining the transmission of the proxy processing declaration packet and the objection notification.
[0118]
FIG. 12 is a flowchart showing the contents of proxy response processing by the terminal device selected as the terminal device acting as a proxy for the transferred terminal device. FIG. 12 shows the details of the processing in step S800 of FIG.
[0119]
In step S801, it is confirmed that access has been made.
[0120]
In step S802, it is determined whether the confirmed access is an access to a proxy address. When the confirmed access is not access to the proxy address but access to the address of a normal terminal device that has not been relocated (step S802: NO), normal connection is performed as shown in step S803. It is. On the other hand, if the confirmed access is an access to a proxy address, the process of step S804 is performed.
[0121]
For example, when the terminal device 120a in FIG. 1 is selected as a terminal device acting as a proxy for the terminal device 220b, the terminal device 120a not only accesses its own address but also before the relocated terminal device 220b is relocated. The access to the address “1.2.0.2” is also accepted.
[0122]
In step S804, the moved address is notified to the access source. For example, when the terminal device 120a of FIG. 1 is selected as a terminal device acting as a proxy for the terminal device 220b, the terminal device 120a sends the address “1.3.0 after the relocation of the terminal device 220b to the access source. .2 ". More specifically, the post-relocation address notification is performed by transmitting a post-relocation address reply packet 900 shown in FIG. 13 to the access source. This post-relocation address reply packet 900 is for urging the access source to reconnect to the post-relocation address. The post-relocation address reply packet 900 is a unicast packet that specifies the receiving destination.
[0123]
The post-relocation address reply packet 900 includes a post-relocation address 901 and a remaining time 902 for performing data transfer processing. The post-relocation address 901 is the same as the post-relocation address 501 included in the post-relocation address notification packet 500 transmitted from the relocated terminal device. The remaining time 902 for performing data processing is the remaining time 704 for performing data transfer processing.
[0124]
As a result, the user who uses the access source terminal device can know that the terminal device has been moved. In addition, the user can know the new address after the transfer of the terminal device and the period during which the service for transferring the data to the new address of the transfer destination can be enjoyed.
[0125]
The relocated address return packet 900 includes an instruction for causing the access source to respond when the access source can reconnect to a new address.
[0126]
In step S805, it is determined whether a response from the access source has been received. If there is a response without an error (step S805: YES), it is determined that the reconnection process has been completed at the access source, and the process ends (step S806). On the other hand, if there is no response such as an error (step S805: NO), it is determined that reconnection processing, that is, the address cannot be changed at the access source, and processing in step S807 is performed.
[0127]
In step S807, the data from the access source is relayed, and the data is transferred to the new address of the relocated terminal device. That is, the terminal device that makes a proxy response functions in the same manner as a proxy server for accessing a request for an access destination on behalf of a client. For example, when the terminal device 120a shown in FIG. 1 is accessed with respect to the address “1.2.0.2” before the relocation of the relocated terminal device 220b, the relocation of the relocated terminal device 220b is performed. The data is transferred to the address “1.3.0.2”.
[0128]
In FIG. 12, a case has been described in which the post-relocation address reply packet 900 is transmitted to the access source, and whether or not to perform data transfer processing (step S807) is determined depending on the presence or absence of a response. However, the present invention is not limited to this case. It is also possible to omit the transmission of the address reply packet 900 after the relocation (steps S804 and S805) and immediately perform data transfer processing.
[0129]
If the access source terminal device accessing the address before relocation has a browser that can understand HTML (Hypertext Markup Language), the relocation device having the structure shown in FIG. Instead of the address reply packet 900, an after-relocation address reply packet described in HTML can be transmitted to the access source. In this case, the post-relocation address reply packet described in HTML is transmitted based on HTTP (Hypertext Transfer Protocol). The browser that has received the relocated address reply packet described in HTML can directly access the relocated terminal device based on the URL (Uniform Resource Locator) included in the relocated address reply packet. In this case, since a general browser can be used, a special configuration for reconnection is not required.
[0130]
FIG. 14 is a flowchart showing the contents of unnecessary element deletion processing. FIG. 14 shows the details of the processing in step S900 of FIG.
[0131]
In step S901, the element number i is set to 1. Here, the element corresponds to each terminal device registered in the existence list 700.
[0132]
In step S902, the i-th element of the existence list 700, that is, the terminal-specific information 701 of the i-th terminal device is acquired.
[0133]
In step S903, the remaining time 704 of the i-th element is acquired.
[0134]
In step S904, it is determined whether or not the remaining time 704 of the i-th element remains. If remaining time 704 remains (step S904: YES), the process of step S905 is performed. On the other hand, if the remaining time 704 does not remain (step S904: NO), the process of step S906 is performed.
[0135]
In step S905, the value of the remaining time 704 of the i-th element is updated. Specifically, when the i-th element is a terminal device connected to the same network as its own device, the remaining time 704 is determined according to the elapsed time since the last existence of the terminal device was confirmed. Less. However, when the presence of the terminal device is confirmed, the remaining time 704 returns to the initial value. Therefore, as long as the existence of the terminal device is confirmed, the i-th element is not deleted from the existence list. On the other hand, when the i-th element is a terminal device relocated to another network, the remaining time gradually decreases from the time when the data transfer process is started.
[0136]
For example, the remaining time 704 corresponding to the terminal device 120a shown in FIG. 1 is updated according to the elapsed time since the presence of the terminal device 120a is confirmed by transmitting the terminal presence information packet 600 in the network 100. Is done. On the other hand, the remaining time 704 corresponding to the terminal device 220b is updated according to the elapsed time after the terminal device 220b is moved to the network 200 and the data transfer processing is started by the terminal device 120a or 120b.
[0137]
Note that the initial value of the remaining time 704, that is, the initial value of the remaining time until each element is deleted from the presence list 700 when the presence is not confirmed, and the initial value of the period for performing data transfer processing are managed in advance. Set by the user.
[0138]
In step S906, it is determined whether a transfer destination address corresponding to the i-th element is registered. If the transfer destination address is registered (step S906: YES), the process of step S907 is performed. On the other hand, when the transfer destination address is not registered (step S906: NO), the process of step S908 is performed.
[0139]
In step S907, as a process when the remaining time 704 does not remain and the transfer destination address is registered, the proxy address corresponding to the transfer destination address is deleted. As a result, the period for performing the data transfer process on behalf of the relocated terminal device ends.
[0140]
In step S908, the i-th element is deleted from the existence list 700. The element is deleted from the presence list 700 when a period for proxying the transferred terminal device has elapsed or when the presence of the terminal device cannot be confirmed over a long period of time.
[0141]
In step S909, it is determined whether or not there is the next element in the existence list 700. When there is a next element (step S909: YES), as shown in step S910, i = i + 1 is incremented, and the value of i is incremented, and the process returns to step S903. On the other hand, if there is no next element, a return is made.
[0142]
As described above, according to the network system of the present embodiment, address management and proxy processing of relocated terminal devices are performed by a plurality of terminal devices without depending on a single dedicated server. Can do. Therefore, even if one terminal device fails, it is possible to prevent all proxy processing from being disabled.
[0143]
In addition, according to the present invention, each terminal device has both a function of notifying the post-relocation address when the terminal device is relocated and a function of performing a proxy on behalf of another proxy terminal device. For this reason, in each terminal device, the hardware configuration and software configuration related to the response process can be shared.
[0144]
Further, in the above description, the maximum number of surrogates that can be handled by one terminal device by the administrator, the initial value of the remaining time until each element is deleted from the existence list, and the period for performing the data transfer process The case where the initial value is set has been described. However, the present invention is not limited to this case. As shown in FIG. 15, a policy server 1000 may be provided. Here, the policy server 1000 is a server that centrally manages the functions of the devices connected to the network. By setting a network operation policy on a single server, the setting information is automatically reflected on each device. The policy server 1000 according to the present embodiment has a maximum proxy number that can be handled by one terminal device, an initial value of the remaining time until each element is deleted from the presence list, and an initial value of a period for performing data transfer processing. Is set as the operation policy uniformly throughout the network system.
[0145]
The operation policy of the policy server 1000 is reflected in both the network before and after the terminal device is moved.
[0146]
In the above description, each terminal device transmits an address change notification (step S200), updates the presence list (step S300), transitions to proxy mode (step S500), and objections in the order shown in FIG. Although cases have been described in which the notification (step S700), proxy response (step S800), and unnecessary element deletion (step S900) processes are executed, the order in which these processes are performed is limited to that shown in FIG. I can't. It is also possible to perform each process in parallel.
[0147]
Further, the present invention does not exclude the adoption of a name server or a DNS server for a part of the network system. In particular, as described above, when a terminal device is relocated within one local network, the address change is managed using a name server, DNS server, etc., while the terminal device is relocated to another local network. In this case, the response method of the present invention can be applied.
[0148]
Furthermore, although the case where the present invention is applied to all terminal devices included in the network system has been described in the above description, the present invention is not limited to this case. Some terminal devices connected to the network system according to the present invention may be ordinary terminal devices.
[0149]
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.
[0150]
【The invention's effect】
As described above, according to the present invention, when one terminal device is relocated from its own network to another network, the relocated terminal device has a plurality of terminals whose addresses after relocation are connected to its own network. Since the terminal device that notifies the device and acts as the proxy for the relocated terminal device is selected from the plurality of notified terminal devices, each time the terminal device is relocated to another network, It is no longer necessary to register addresses and the like on the server, and the burden of registration associated with relocation is reduced.
[0151]
Further, according to the present invention, it is possible to prevent occurrence of a situation in which all proxy processing according to access is interrupted in place of a transferred terminal device when a problem occurs in one device.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of a network system.
FIG. 2 is a block diagram showing an internal configuration of a terminal device.
FIG. 3 is a main flowchart showing the overall processing of each terminal device.
FIG. 4 is a flowchart showing details of post-relocation address notification processing;
FIG. 5 is a diagram schematically showing a post-relocation address notification packet.
FIG. 6 is a flowchart showing the contents of a presence list update process.
FIG. 7 is a diagram schematically showing a terminal presence information packet.
FIG. 8 is a diagram illustrating an example of a presence list.
FIG. 9 is a flowchart showing the contents of a transition process to a proxy mode.
FIG. 10 is a diagram schematically showing a proxy processing declaration packet.
FIG. 11 is a flowchart showing details of objection notification processing;
FIG. 12 is a flowchart showing the contents of proxy response processing.
FIG. 13 is a diagram schematically showing a post-relocation address reply packet.
FIG. 14 is a flowchart showing details of unnecessary element deletion processing;
FIG. 15 is a block diagram of a network system when a policy server is used.
[Explanation of symbols]
100, 200, 300 ... network,
120a, 120b, 220a, 220b, 320a, 320b... Terminal device,
400 ... Internet,
500 ... Address notification packet after relocation,
501: Address after relocation,
600 ... terminal presence information packet,
700 ... existence list,
800 ... Proxy processing declaration packet,
900: Address reply packet after relocation.

Claims (9)

When one terminal device is relocated from its own network to which a plurality of terminal devices are connected to another network, the response method responds to access to the address before relocation on behalf of the relocated terminal device,
The relocated terminal device transmits a packet including the relocated address to the own network, and a plurality of terminal devices connected to the own network receive the packet, thereby Obtaining an address;
Each terminal device that has received the packet, when proxying the relocated terminal device is possible, notifying other terminal devices connected to the own network to proxy,
A response method , comprising: a step of selecting a terminal device in charge of the transferred terminal device from a plurality of terminal devices that have received the packet based on a notification that the proxy is to be performed. .   When access is made to the address of the relocated terminal device before the relocation, the terminal device acting as a proxy for the relocated terminal device notifies the access source of the relocated address of the relocated terminal device. The response method according to claim 1, wherein:   When an address before the relocation of the relocated terminal device is accessed, the terminal device in charge of the relocated terminal device performs data transfer to the relocated address of the relocated terminal device. The response method according to claim 1.   The response method according to claim 1, wherein the terminal device in charge of the transferred terminal device acts as a proxy for a predetermined number of terminal devices or less per device. The terminal device that has received the notification that the proxy is performed has a higher priority regarding the proxy than the notification source terminal device, and instructs the notification source terminal device not to perform the proxy. The response method according to claim 1 , wherein: 2. The response method according to claim 1 , wherein the terminal device that has received the notification that the proxy is performed does not perform the proxy when the proxy-related priority is lower than the notification source terminal device. The response method according to claim 5 or 6 , wherein the priority related to the proxy is set according to a period during which the terminal device is continuously connected to the network. When one terminal device is relocated from its own network to which a plurality of terminal devices are connected to another network, the network system responds to access to the address before relocation on behalf of the relocated terminal device,
The relocated terminal device transmits a packet including the relocated address to the own network, and a plurality of terminal devices connected to the own network receive the packet, thereby determining the relocated address. Acquired,
Each terminal device that has received the packet notifies other terminal devices connected to the local network that proxying is performed when the transferred terminal device can be substituted,
A network system, wherein a terminal device in charge of a transferred terminal device is selected from a plurality of terminal devices that have received the packet based on a notification that the proxy is to be performed . A terminal device having a response unit for responding to access the address of the previous relocation proxy to another terminal apparatus other terminals that are moved set,
When the terminal device itself is relocated from its own network to another network, a plurality of other terminal devices connected to the own network are transmitted by transmitting packets including the relocated address to the own network. To obtain the address after relocation to the other plurality of terminal devices,
When another terminal device connected to the own network to which the terminal device is connected is relocated to another network, the packet including the relocated address of the relocated terminal device is relocated. Received from the terminal device, obtain the relocated address of the relocated terminal device,
If the transferred terminal device can be substituted, the other terminal device connected to the local network is notified that the proxy is to be performed, and between the local device and the other terminal device. The terminal device is characterized in that it selects which terminal device is in charge of proxy .

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