JP7110739B2 - Communication control device, communication control program and network communication system - Google Patents

Description

The present invention relates to a communication control device, a communication control program, and a network communication system.

Conventionally, for example, in government offices or hospitals, multiple networks were used, such as separating a network for handling highly confidential information such as personal information from a network for handling less confidential information such as office work. They are often used differently. Further, for example, when companies are merged by M&A (Mergers and Acquisitions), etc., different networks may be used for different departments even though they are the same company on the same floor in the building.

In this case, installing an image forming apparatus such as a multifunction peripheral (MFP) or a printer for each network increases the management cost, and installing a plurality of image forming apparatuses increases the occupied area of the floor. Therefore, it is required to reduce the number of installed image forming apparatuses and connect a plurality of networks to one image forming apparatus.

Here, in a network communication system in which packet information transmitted via a plurality of networks is processed by communication equipment such as one (or a plurality of) image forming apparatuses, information equipment connected to each network and an image forming apparatus It is preferable to periodically or irregularly perform maintenance on a relay processing device that relays communication with a communication device such as a communication device. During this maintenance, the relay processing device and the network are disconnected to perform the maintenance.

However, if the processing status of the communication device for the job of the information device connected to the network to be disconnected is unknown, the network is disconnected even though the processing (job) of the information device is being processed on the communication device side. Then, a communication failure occurs, causing inconveniences such as the processing to stop in the middle of the processing or the information to disappear. For this reason, in a network communication system in which packet information transmitted via a plurality of networks is processed by one (or a plurality of) communication devices, maintenance of the relay processing device is expected to be difficult. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. An object of the present invention is to provide a communication control device, a communication control program, and a network communication system that enable maintenance of a relay processing device without requiring maintenance.

In order to solve the above-described problems and achieve the object, the present invention provides communication control of transmission/reception information between at least one communication device and a network device provided in at least one of a plurality of networks. and a storage unit that stores session information established between the communication device and the network device. drop the new establishment request, monitor the communication between the communication device and the network device based on the session information stored in the storage unit, and complete the communication between all the communication devices and the network device and a control unit for executing maintenance when the maintenance is performed. During maintenance, if the received packet is a UDP packet, an SNMP packet, and is information indicating the state of the communication device, the control unit proxies the maintenance state as a proxy for the communication device. respond.

According to the present invention, in a network communication system in which packet information transmitted via a plurality of networks is processed by one (or a plurality of) communication devices, it is possible to maintain relay processing devices without causing communication failures. It has the effect of being able to

FIG. 1 is a system configuration diagram of a network communication system according to an embodiment. FIG. 2 is a block diagram showing the configuration of a network control unit provided in the network communication system according to the embodiment. FIG. 3 is a diagram showing an example of a network setting screen in the network communication system according to the embodiment. FIG. 4 is a diagram showing an example of a maintenance setting screen in the network communication system according to the embodiment. FIG. 5 is a flow chart showing the flow of maintenance processing of the network control unit in the network communication system according to the embodiment. FIG. 6 is a flow chart showing the flow of maintenance availability determination operation in the network communication system according to the embodiment. FIG. 7 is a flow chart showing the flow of processing by the network control unit during maintenance in the network communication system according to the embodiment. FIG. 8 is a sequence diagram showing the operation of each unit in the network communication system according to the embodiment when maintenance of the interface box is started while each MFP is communicating via the interface box.

A network communication system according to an embodiment will be described below.

(Overview)
A network communication system according to an embodiment monitors a communicating session in a network communication system in which a plurality of networks are separated by relay processing devices so as not to communicate with each other. Then, established sessions are not blocked, newly established communication is blocked, and after processing of all established sessions is completed, the relay function of the relay processing device is stopped.

As a result, it is possible to prevent the occurrence of a communication failure and enable the maintenance of the relay processing device, thereby preventing inconveniences such as interruption of processing or loss of information in the middle of information processing. .

(System configuration)
FIG. 1 is a system configuration diagram of a network communication system according to an embodiment. As shown in FIG. 1, the network communication system of the first embodiment includes a main MFP_M (Multifunction Peripheral), an interface box (an example of a communication control device) 1, and a plurality of networks Net_A0 to Net_C0. , Net_A1 to Net_C1, and Net_I.

MFP_M is an example of a communication device. The communication device is not particularly limited as long as it is capable of network communication, even if it is other than the multifunction peripheral MFP_M. For example, any device such as a projector compatible with network communication, an electronic whiteboard or electronic blackboard compatible with network communication, or the like may be used. Also, in this example, the multifunction peripheral MFP_M and the interface box 1 are shown as physically different devices, but the two are integrated by, for example, providing the interface box 1 as an expansion board for the multifunction peripheral MFP_M. may be

MFP_M is connected to multiple networks (Net_A0, Net_B0, Net_C0) via interface box 1 . The network interface of the multifunction peripheral MFP_M has, for example, a MAC address of "00-00-5E-00-53-22".

Networks Net_A0, Net_B0, and Net_C0 are connected to networks Net_A1, Net_B1, and Net_C1 via routers R_A, R_B, and R_C, respectively. Network Net_I is also connected to network Net_C0 and network Net_C1 via router R_C. Networks Net_C0 and Net_C1 are also connected to the Internet via router R_C and network Net_I. In this example, the network Net_A and the network Net_B are not connected to the Internet in consideration of communication security, but they may be connected to the Internet.

Here, the networks connected to the multifunction peripheral MFP_M are divided into a Net_A system grouped by networks Net_A0 and Net_A1, a Net_B system grouped by networks Net_B0 and Net_B1, and a Net_C system grouped by networks Net_C0, Net_C1 and Net_I. ing. The networks of each system are separated so that IP (Internet Protocol) communication cannot be performed. In this example, the explanation is based on the assumption that IP (Internet Protocol) communication is not possible between the networks of each system, but communication between the networks of each system is possible according to security requirements. may be

Personal computer devices PC_A0, PC_B0 and PC_C0 are connected to networks Net_A0, Net_B0 and Net_C0, respectively. Also, a personal computer device PC_A1, a server device SV_A1, and a multifunction peripheral MFP_A are connected to the network Net_A1. Also, a personal computer device PC_B1 and a server device SV_B1 are connected to the network Net_B1. A server device SV_B2 is connected to the network Net_B1 via a router R_B2. Also, a personal computer device PC_C1, a server device SV_C1, and a multifunction peripheral MFP_C are connected to the network Net_C1.

Note that the personal computer device PC_A0 and the like, the server device SV_A1 and the like, the multifunction peripheral MFP_A and the multifunction peripheral MFP_C are examples of network devices.

Each personal computer device such as the personal computer device PC_A1 sends a print request and device information using SNMP (simple network management protocol) to the MFP_M. The multi-function peripheral MFP_M transfers the file information formed by the scanning process to the server device SV_A1 or the like. Note that the print request, the transmission of the device information by SNMP, the transfer of the scanned file information, and the like described in this example are examples, and other communications may be used.

The interface box 1 restricts communication between the network Net_A system, the network Net_B system, and the network Net_C system, and then restricts the communication between the network Net_A system and the multifunction peripheral MFP_M, and the communication between the network Net_B system and the multifunction peripheral MFP_M. and communication between the network Net_C and the multifunction peripheral MFP_M.

(Configuration of interface box)
FIG. 2 is a diagram showing a schematic configuration of the controller of the interface box 1. As shown in FIG. As shown in FIG. 2, the controller of the interface box 1 has a network control section 11 (an example of a control section), a storage section 12, a transmission/reception section A to a transmission/reception section C, and a transmission/reception section M. FIG. As the storage unit 12, a ROM (read-only memory), a RAM (random-access memory), a HDD (hard disk drive), or the like can be used.

By executing a network control application program (network control AP) stored in the storage unit 12, the network control unit 11 controls the multifunction peripheral MFP_M and the information devices connected to each network (multifunction peripheral, personal computer device, and server device).

In addition, the network control unit 11 executes the network control AP to monitor sessions in communication between the multifunction peripheral MFP_M and the information devices connected to each network. Then, established sessions are not blocked, newly established communication is blocked, and after processing of all established sessions is completed, the relay function of the relay processing device is stopped. This enables maintenance of the relay processing device (stopping the device, changing settings for the device, etc.) while preventing the occurrence of communication failure.

The network control AP may be provided by recording file information in an installable format or an executable format on a computer-readable recording medium such as a CD-ROM or flexible disk (FD). Also, the network control AP may be provided by being recorded on a computer-readable recording medium such as a CD-R, a DVD (Digital Versatile Disk), a Blu-ray (registered trademark) disk, or a semiconductor memory. Also, the network control AP may be provided by being installed via a network such as the Internet. Also, the network control AP may be provided by being preliminarily incorporated in a ROM or the like in the device.

The transmitting/receiving units A to C and M receive and transmit packet information transmitted via the network. As the transmitting/receiving units A to C and the transmitting/receiving unit M, for example, a network interface for performing Ethernet (registered trademark) communication can be used. In addition, other network interfaces such as an interface compatible with a PCI Express card or a USB (Universal Serial Bus) interface may be used. Further, the transmitting/receiving units A to C and the transmitting/receiving unit M are illustrated as wired interfaces, but may be wireless interfaces.

In addition to the network control AP described above, the storage unit 12 stores a "setting table" that stores the network addresses of each network and the IP addresses set to each device of the system. The storage unit 12 also stores a “session table” that indicates a session that is stored immediately before maintenance (suspension or setting change) of the interface box 1 is performed.

(setting table)
Table 1 below shows an example of the network address of each network stored in the "setting table". It should be noted that the "setting table" is preferably stored in, for example, a non-volatile memory.

As shown in Table 1, the network address of network Net_A0 is "192.168.1.0/24". The network address of network Net_A1 is "192.168.10.0/24". The network address of network Net_B0 is "172.16.1.0/24". The network address of network Net_B1 is 172.16.10.0/24". The network address of network Net_C0 is "10.0.1.0/24". The network address of network Net_C1 is "10.0.10.0/24". The network address of network Net_I is "203.0.113.0/29". Network Net_I is a segment for connecting to the Internet.

As shown in Table 1, the network addresses of each network Net_A0, Net_A1, Net_B0, Net_B1, Net_C0, Net_C1, and Net_I are set so as not to overlap. Actually, even if it is other than such a setting example, it is sufficient that the IP addresses of the server devices that directly communicate with the MFP_M do not overlap. Also, even if the IP addresses of the server devices that communicate directly are duplicated, static NAPT (Network Address Port Translation) settings may be made.

Next, Table 2 below shows an example of the IP address of each device in the system stored in the "setting table".

As shown in Table 2, the IP address of the MFP_M is "192.168.1.20/24" and the default gateway is "192.168.1.1/24". The interface box 1 has a total of three IP addresses "192.168.1.10/24", "172.16.1.10/24" and "10.0.1.10/24". ing. Also, the IP addresses of the default gateways of the interface box 1 are "192.168.1.1/24", "172.16.1.1/24", and "10.0.1.1/24". It has become.

The IP address of the personal computer PC_A0 is "192.168.1.100/24", and the IP address of the default gateway is "192.168.1.1/24". The IP addresses of router R_A are "192.168.1.1/24" and "192.168.10.1/24".

The IP address of the personal computer PC_A1 is "192.168.10.100/24", and the IP address of the default gateway is "192.168.10.1/24". The IP address of the server device SV_A1 is "192.168.10.11/24", and the IP address of the default gateway is "192.168.10.1/24".

The IP address of the MFP_A is "192.168.10.20/24", and the IP address of the default gateway is "192.168.10.1/24". The IP address of the personal computer PC_B0 is "172.16.1.100/24", and the IP address of the default gateway is "172.16.1.1/24".

The IP addresses of router R_B are "172.16.1.1/24" and "172.16.10.1/24". The IP address of the personal computer PC_B1 is "172.16.10.100/24", and the IP address of the default gateway is "172.16.10.1/24". The IP address of the server device SV_B1 is "172.16.10.11/24" and the default gateway is "172.16.10.1/24".

The IP addresses of router R_B2 are "172.16.10.5/24" and "192.168.10.1/24". The IP address of the server device SV_B2 is "192.168.10.11/24", and the IP address of the default gateway is "192.168.10.1/24". That is, the IP address of server device SV_B2 is the same IP address as the IP address of server device SV_B1.

The IP address of the personal computer PC_C0 is "10.0.1.100/24", and the IP address of the default gateway is "10.0.1.1/24". Also, the IP addresses of the router R_C capable of transmitting packet information (an example of transmission/reception information) to the Internet are "10.0.1.1/24" and "10.0.10.1/24". and "203.0.113.2/29", and the IP address of the default gateway is "203.0.113.1/29". The IP address of the personal computer PC_C1 is "10.0.10.100/24", and the IP address of the default gateway is "10.0.10.1/24".

The IP address of the server device SV_C1 is "10.0.10.11/24", and the IP address of the default gateway is "10.0.10.1/24". Also, the IP address of the multi-function peripheral MFP_C is "10.0.10.20/24", and the IP address of the default gateway is "10.0.10.1/24".

As can be seen from Table 2, one IP address is assigned to each of the MFP, personal computer device, and server device to enable communication via the network. A router is assigned a number of IP addresses corresponding to the networks to which it is connected. Logically, the server device and the router may be one unit, or may be redundantly configured by a plurality of devices.

(session table)
Next, Table 3 below shows an example of session information of sessions established at the time of performing maintenance (suspension or setting change) of the interface box 1, stored in the "session table". Note that the memory that stores the “session table” may be, for example, a volatile memory.

In this Table 3, the local IP address/port (local IP addr/port) is the IP address and port of the MFP_M or the IP address and port of the interface box 1 . On the other hand, the remote IP address/port (remote IP addr/port) is the local IP address, the IP address of the device opposite the port, and the port.

The protocol indicates ICMP (Internet Control Message Protocol)/TCP (Transmission Control Protocol)/UDP (User Datagram Protocol) or the like. In the case of TCP, there is a concept of session, and data is transmitted after establishing a session. On the other hand, in the case of UDP, there is no concept of session establishment in the transport layer.

The first row of Table 3 indicates that the UDP packet is in the CONNECTED state. The network control unit 11 manages that communication has been performed for a certain period of time after the UDP packet has passed, and permits reverse communication to pass. For UDP, there is actually no notion of a session, so there is no need to manage it.

The second row of Table 3 indicates a session when a file is being sent from the multifunction peripheral MFP_M to the server device SV_C1 using the SMB (Server Message Block) protocol. Further, the third row of Table 3 shows a session when IP facsimile (IP-FAX) is transmitted from MFP_A to MFP_M. The fourth row of Table 3 shows a session when IP-FAX is sent from MFP_M to MFP_A.

A TCP communication session is completed by an RST packet (reset packet) or a FIN packet (finish packet). Moreover, the network control unit 11 determines that the session is completed when there is no communication for a certain period of time. The network control unit 11 erases the session information illustrated in Table 3, which indicates that the session has been completed, from the session table. As a result, the session information during the session is stored in the session table.

(Maintenance operation of the interface box)
Since the interface box 1 operates based on the set setting values, it is necessary to reflect the changed settings in the processing of the network control unit 11 when the settings are changed. This reflection may or may not affect network communication, depending on the content of the setting change. However, when the network settings or the like are changed, it is necessary to temporarily cut off the communication that the interface box 1 is forwarding.

Examples of changes to the network settings include the network settings of the interface box 1 set via the network setting screen shown in FIG. 3, and the network settings of the interface box 1 set via the maintenance setting screen shown in FIG. There are maintenance control settings, etc. The network settings of the interface box 1 set via the network setting screen shown in FIG. 3 may be set remotely or locally. When the network settings are changed via this network setting screen, network communication disconnection occurs in the interface box 1 as the network settings are reflected.

A timeout (maximum waiting time) can be set in the maintenance control settings of the interface box 1 that are set via the maintenance setting screen shown in FIG. By setting the value to "0", it is also possible not to generate a timeout. Further, the operation method can be changed by changing the transmission of the maintenance instruction to the MFP_M between "Yes (valid)" and "No (invalid)". Also, the SNMP offline response can be changed between "yes (valid)" and "no (invalid)", and it is possible to change whether the interface box 1 makes a proxy response.

Furthermore, it is possible to select whether to drop (Drop) or reset (RST) the new connection processing method during maintenance. These setting values are settings that do not require disconnection of network communication. Initially, the timeout was set to "0 minutes", but later it is possible to change the timeout to "1 minute".

"Drop" is a process of intentionally blocking a packet or unintentionally causing a packet to disappear or be lost.

As described above, when the network settings or the like are changed, it is necessary to temporarily cut off the communication that the interface box 1 is forwarding. , which may take a long time. For example, when it is necessary to start the operating system (OS) of the interface box 1 when reflecting the value, a long-time communication disconnection occurs. Due to this communication disconnection, communication between the multi-function peripheral MFP_M and other devices becomes impossible, and in some cases data loss may occur during communication.

In the maintenance of the interface box 1, maintenance of the interface box 1 has been performed with the multifunction peripheral MFP_M in a non-communicating state so far in order to prevent loss of data. However, since the multifunction peripheral MFP_M and the interface box 1 are operated by different control units (CPUs), it is necessary to operate the multifunction peripheral MFP_M and the interface box 1 respectively, requiring complicated operations.

For this reason, in the network communication system of the embodiment, setting values are reflected in the interface box 1 in a state where communication between the multifunction peripheral MFP_M and other devices is stopped. As a result, the interface box 1 can be maintained without any troublesome operation and data loss can be prevented.

(maintenance processing)
The flowchart of FIG. 5 is a flowchart showing the flow of maintenance processing in the network control unit 11. As shown in FIG. In the flowchart of FIG. 5, the network control unit 11 transitions to the maintenance state at the timing when the maintenance start operation is detected (step S1). After transitioning to the maintenance state, the network control unit 11 determines whether or not maintenance can be performed (steps S2 and S3). The operation of determining whether maintenance is possible or not will be described later with reference to the flowchart of FIG. If it is determined that maintenance can be performed (step S3: Yes), the network control unit 11 reflects the setting (step S4). Note that a network disconnection occurs when the settings are reflected.

On the other hand, if it is determined that maintenance cannot be performed (step S3: No), the network control unit 11 waits for a certain period of time, such as 10 seconds (step S5), and if the time has not expired (step S6: No). , the process is returned to step S2, and the decision as to whether or not maintenance is possible is made again. On the other hand, if the time has expired (if a certain period of time has passed: step S6: Yes), the process proceeds to step S4 to forcibly reflect the settings. As a result, the maximum maintenance time can be determined, and maintenance can be performed in a planned manner while reducing the impact on the user to some extent.

(Operation to determine whether maintenance is possible)
FIG. 6 is a flow chart showing the flow of the operation for determining whether maintenance is possible in step S2 described above. In determining whether or not maintenance can be performed, the network control unit 11 first executes a connection determination process (step S11). As a result of this connection determination process, it is determined whether maintenance is possible (step S12: Yes) or not (step S12: No).

Based on the number of TCP connections stored in the session table of the storage unit 12, the network control unit 11 determines whether maintenance is possible. Specifically, the network control unit 11 determines that maintenance is possible when the number of TCP connections becomes "0", for example. The presence or absence of UDP communication can be ignored. As a result, even in the presence of UDP packets, if there are no TCP sessions, the maintenance mode can be entered and the maintenance time can be shortened. Note that the network control unit 11 may determine that it is possible to shift to the maintenance mode after there is no communication, including UDP communication.

(Processing of network control unit during maintenance)
FIG. 7 is a flow chart showing the processing flow of the network control unit 11 during maintenance. Upon receiving the packet, the network control unit 11 checks whether the interface box 1 is currently under maintenance (steps S21 and S22). If it is determined that the current state is not the maintenance state (step S22: No), the network control unit 11 controls transfer of the received packet to the designated device (step S28).

On the other hand, if it is determined that the interface box 1 is currently under maintenance (step S22: Yes), the network control unit 11 determines whether the received packet is a new TCP session packet or a UDP packet. (step S23). If it is determined that the packet is neither of the packets (step S23: No), the network control unit 11 determines whether or not the TCP session has been closed (step S26). When determining that the TCP session is not closed, the network control unit 11 transfers the received packet to the specified device (step S28).

On the other hand, if it is determined that the TCP session has been closed (step S26: Yes), the network control unit 11 performs processing for deleting the TCP session from the session table of the storage unit 12, that is, subtraction processing of the number of sessions. (Step S27), the received packet is transferred to the designated device (Step S28).

On the other hand, when it is determined in step S23 that the received packet is a new TCP session packet or a UDP packet (step S23: Yes), the network control unit 11 determines whether the received packet is an SNMP packet. is determined (step S24). If it is determined that the packet is not an SNMP packet (step S24: No), the network control unit 11 drops the packet (step S29). Note that, as described with reference to FIG. 4, the network control unit 11 can also transmit a reset signal instead of a drop depending on settings.

The network control unit 11 also outputs "hr Device Status", which is a UDP packet and is an SNMP packet, indicating the status of the printer, such as running, warning, down, etc., described in RFC3805 (Printer MIB v2), for example. "hr Printer Status" indicating the state of idle, printing, warm-up, etc.; ), instead of the multifunction device MFP_M, a proxy response is made to the device that is the source of the received packet that the device is in an unusable state (step S25). This allows the user to know from the display of the printer driver that the printer is currently unavailable.

(Maintenance operation during communication)
FIG. 8 is a sequence diagram showing the operation of each part when the maintenance of the interface box 1 is started while the MFP_M and the MFP_B are performing IP-FAX. In FIG. 8, when the user operates the MFP_A to perform IP-FAX transmission (step S31), a TCP session is established with the network control unit 11 via the transmission/reception unit A of the interface box 1. (step S32, step S33). Also. Along with this, a TCP session is established between the network control unit 11 and the multifunction device MFP_M via the transmission/reception unit M (steps S34 and S35).

When a TCP session is established between MFP_A and MFP_M, IP-FAX data is transmitted from MFP_A to MFP_M via network control unit 11 (steps S36 to S39). .

Assuming that the administrator designates execution of maintenance from the user interface (UI) of the interface box 1 while IP-FAX communication is being performed between the MFP_A and the MFP_M in this way (step S40 , step S41). Although the administrator operates the UI of the interface box 1 to specify the execution of maintenance, it is also possible to specify the execution of maintenance by remote operation via a network. Alternatively, local settings such as an operation panel may be used.

When execution of maintenance is specified, the network control unit 11 shifts to the maintenance state (step S42), and determines whether maintenance is possible (step S43). At this time, the interface box 1 instructs the MFP_M to shift to maintenance (steps S44 and S45). By this maintenance transition instruction, the multifunction peripheral MFP_M recognizes that the interface box 1 is in the maintenance state, and transitions to a state in which it does not accept new print instructions, IP-FAX jobs, etc. (maintenance transition: step S46). It should be noted that the output of the instruction to shift to maintenance and the shift to maintenance of the multifunction peripheral MFP_M are not necessarily performed at the time of maintenance, and it is sufficient if the interface box 1 has shifted to the maintenance state.

When the interface box 1 is in the maintenance state and the user instructs the MFP_M to execute printing (steps S47 to S49), the network control unit 11 of the interface box 1 establishes a new TCP connection. drop (step S50). As a result, the print execution request made via the personal computer PC is rejected. Instead of dropping the packet for establishing the TCP connection, it may be reset (RST) (see FIG. 4). By resetting, the personal computer PC can detect that printing is currently disabled without waiting for timeout.

Next, when the user instructs to check the printer status because printing cannot be executed (step S51), the printer driver of the personal computer PC sends an SNMP request as a printer status acquisition request to the MFP_M. Send. This printer status acquisition request is transmitted to the network control section 11 via the transmission/reception section A of the interface box 1 (steps S52 and S53). In this case, since the printer is under maintenance, the network control unit 11 makes a proxy response of the multifunction peripheral MFP_M to notify the user's personal computer PC that the printer is offline (step S62).

Next, when the IP-FAX communication session is completed, the TCP session between the multifunction peripherals MFP_Ato MFP_M is closed (steps S54 to S57). As a result, the network control unit 11 deletes the established TCP session stored in the session table of the storage unit 12 . In this state, data loss does not occur even if communication is interrupted. Therefore, when the TCP session being connected is deleted from the session table, the network control unit 11 determines that maintenance is possible by determining whether maintenance is possible (step S58), and performs the setting reflection operation (step S59).

It should be noted that "reflection of settings" means that the network control unit is updated based on the settings specified by the user or the like based on the network setting screen described using FIG. 3 or the maintenance setting screen described using FIG. 11 is operable, the setting values of the network control AP and the like are rewritten.

When the reflection of such settings is completed, the network control unit 11 instructs the multifunction peripheral MFP_M to return from the maintenance state (step S60). As a result, the multifunction peripheral MFP_M can accept a new job (step S61). Note that this return instruction is not essential, as is the maintenance transfer instruction.

(Effect of Embodiment)
As is clear from the above description, in the network communication system of the embodiment, the network control unit 11 of the interface box 1 monitors the communicating session, does not block the established session, and newly establishes the session. The interface box 1 is maintained after the communication to be attempted is cut off and the processing of all established sessions is completed.

By performing maintenance on the interface box 1 after the processing of the established session is completed, the interface box 1 can be maintained without any communication failure.

In addition, the network control unit 11 determines whether or not maintenance of the interface box 1 can be executed based on the number of TCP sessions being connected. Specifically, when the number of TCP sessions stored in the session table of the storage unit 12 becomes "0", it is determined that maintenance is possible. As a result, it is possible to prevent the inconvenience of delaying maintenance (reflection of settings, etc.) due to unnecessary UDP packets.

In addition, the network control unit 11 does not have to be aware of the presence of network devices on the way by dropping new packets when shifting to the maintenance state. Alternatively, when the network control unit 11 shifts to the maintenance state, by resetting a new packet, the user's personal computer side cannot communicate with the MFP_M immediately after starting communication. can be detected.

Further, when the network control unit 11 shifts to the maintenance state, it determines whether or not maintenance can be performed. When it is determined that maintenance cannot be performed, the network control unit 11 performs maintenance after a certain period of time has elapsed (FIG. 5: step S3, step S5 to step S6). This makes it possible to perform maintenance in a planned manner.

In addition, when performing maintenance, the network control unit 11 notifies the MFP_M that the maintenance state will be entered ( FIG. 8 : Steps S44 to S46). can be maintained.

Further, when receiving an SNMP request, the network control unit 11 makes a proxy response of the maintenance status as a proxy of the multifunction device MFP_M ( FIG. 8 : step S62). As a result, the user can recognize the maintenance status via, for example, a printer driver.

Finally, the above-described embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be embodied in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. In addition, the embodiments and modifications of the embodiments are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Further, the present invention can be implemented by an engineer having ordinary knowledge in the field of information processing technology by means of a device configured by connecting ASICs (Application Specific Integrated Circuits) or conventional circuit modules. be.

Also, each function described in the above embodiments can be realized by one or more processing circuits (Circuits). The "processing circuit" includes a processor programmed by software to execute each function, an ASIC designed to execute each function, and hardware such as circuit modules.

1 interface box 11 network control unit 12 storage unit A transmission/reception unit B transmission/reception unit C transmission/reception unit M transmission/reception unit MFP_A MFP MFP_M MFP Net_A0 network Net_A1 network Net_B0 network Net_B1 network Net_C0 network Net_C1 network Net_l network R_A router R_B router R_C router

JP 2009-217841 A

Claims (10)

A communication control device for controlling communication of transmission/reception information between at least one communication device and a network device provided in at least one of a plurality of networks,
a storage unit that stores session information established between the communication device and the network device;
During maintenance performed by stopping communication between the communication device and the network device, a new session establishment request is dropped, and based on the session information stored in the storage unit, the communication device and the network device a control unit that monitors communication between network devices and performs maintenance when communication between all the communication devices and the network devices is completed ;
When the received packet is a UDP packet, an SNMP packet, and information indicating the state of the communication device at the time of the maintenance, the control unit performs maintenance on behalf of the communication device. A communication control device characterized in that it makes a proxy response of the state of 2. The communication control apparatus according to claim 1, wherein said control unit determines whether or not maintenance can be executed based on the number of TCP sessions being established among the session information in said storage unit. 3. The communication control device according to claim 1, wherein the control unit drops or resets new packets during the maintenance. The control unit determines whether or not the maintenance can be performed during the maintenance, and when it is determined that the maintenance cannot be performed, the maintenance is performed after a certain period of time has elapsed. 4. The communication control device according to any one of items 3. The communication control apparatus according to any one of claims 1 to 4, wherein the control unit notifies the communication device that the maintenance state will be entered during the maintenance. When the communication device is a printer, the information indicating the state of the communication device includes: running, warning, down, idle, printing, warming up, offline, out of paper, running out of toner, and paper jam. The communication control device according to any one of claims 1 to 5, comprising any one of: The communication control device according to any one of claims 1 to 6, wherein said control unit ignores the presence or absence of UDP communication included in said session information and determines whether or not maintenance is possible. 7. The controller according to any one of claims 1 to 6, wherein in the session information, the control unit determines that the transition to the maintenance mode is possible after there is no communication between the communication device and the network device, including UDP communication. or the communication control device according to claim 1. A communication control program for a computer that controls communication of transmission and reception information between at least one communication device and a network device provided in at least one of a plurality of networks,
said computer,
a storage control unit that controls storage of session information established between the communication device and the network device in a storage unit;
During maintenance performed by stopping communication between the communication device and the network device, a new session establishment request is dropped, and based on the session information stored in the storage unit, the communication device and the network device function as a control unit that monitors communication between network devices and performs maintenance when communication between all the communication devices and the network devices is completed ;
When the received packet is a UDP packet, an SNMP packet, and information indicating the state of the communication device at the time of the maintenance, the control unit performs maintenance on behalf of the communication device. A communication control program characterized in that it responds by proxy to the state of at least one communication device;
a network device provided in at least one of a plurality of networks;
a communication control device for controlling communication of transmission/reception information between the communication device and the network device;
The communication control device is
a storage unit that stores session information established between the communication device and the network device;
During maintenance performed by stopping communication between the communication device and the network device, a new session establishment request is dropped, and based on the session information stored in the storage unit, the communication device and the network device a control unit that monitors communication between network devices and performs maintenance when communication between all the communication devices and the network devices is completed ;
When the received packet is a UDP packet, an SNMP packet, and information indicating the state of the communication device at the time of the maintenance, the control unit performs maintenance on behalf of the communication device. A network communication system characterized by : a proxy response of the state of

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