JP2009253743A - Communication system, transmission device, and transmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and effectively deal with a software fault in a communication system wherein each of transmission devices constituting a network is logically divided into a plurality of virtual transmission devices and each of the virtual transmission devices is configured to be operated by a routing software prepared individually. <P>SOLUTION: A transmission device receives a signal, determines a transfer destination of the signal in accordance with a prescribed protocol, and transmits the signal to the transfer destination. The transmission device is logically divided into a plurality of virtual transmission devices. Among the plurality of virtual transmission devices, a first virtual transmission device is operated by routing software of a first version. Among the plurality of virtual transmission devices, a second virtual transmission device is operated by a second routing software newer than the first version. A quantitative magnitude relation of signal processing resources assigned to the first and the second virtual transmission devices is inverted before and after a software fault occurs in routing due to the second routing software. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transmission apparatus, a control method, and a communication system using a technology for virtually dividing a signal processing resource of a communication apparatus.

  In communication systems and information systems, how to deal with system failures due to hardware and / or software failures is a very important issue. As a method of preventing a system failure, there is a method of redundancy such as duplication of hardware. However, it is not always possible to provide extra hardware.

On the other hand, there is a virtualization technology in which one computer is divided into a plurality of virtual computers, and a separate operating system (OS) or application is prepared for each of them (see Non-Patent Document 1 for this). In the virtualization technology, hardware resources such as a processor, a memory, a disk, and a network interface are logically divided. Each divided resource is assigned to a virtual computer called a virtual machine, and each virtual computer behaves like an independent computer. A virtual machine appears to be multiple computers, so even if the hardware is not actually duplicated, it appears as if the hardware is duplicated. Thereby, the tolerance with respect to a system failure can be improved. A virtualization technology called "VMWare VMotion" tries to avoid a failure by moving a running virtual machine to other hardware without downtime when a failure occurs in the system.
Rosenblum M., Garfinkel T, "Virtual machine monitors: current technology and future trends", IEEE Computer Volume 38 Issue 5, May 2005 pp.39-47

  In recent information communication systems, bugs are increasing due to the enlargement of software scale. In order to provide new services, functions are frequently added to existing software, and new bugs often occur due to the addition of the functions. In this way, failures caused by software have been increasing especially recently. If the cause of the failure is software, even if you try to deal with it by making the hardware redundant, the software used is the same, so the same failure may occur on all redundant hardware There is. In the worst case, there is a possibility that the system will be down, and the burden on the system to prevent it will be considerably increased.

  The problem of the present invention is that each of the transmission devices constituting the network is logically divided into a plurality of virtual transmission devices, and each of the virtual transmission devices is operated by routing software prepared individually. It is a simple and effective way to deal with software failures in a communication system.

  In the present invention, a transmission apparatus that transmits signals between communication nodes of a network is used. The transmission apparatus includes means for receiving a signal, means for determining a transfer destination of the received signal according to a predetermined protocol, and means for transmitting the received signal to the transfer destination. The transmission apparatus is logically divided into a plurality of virtual transmission apparatuses. A first virtual transmission device of the plurality of virtual transmission devices operates with a first version of routing software. A second virtual transmission device among the plurality of virtual transmission devices operates with second routing software that is newer than the first version. The quantitative relationship between the signal processing resources allocated to the first and second virtual transmission apparatuses is reversed before and after a software failure occurs in routing by the second routing software.

  According to the present invention, it is possible to easily and effectively cope with a software failure in the communication system as described above.

  A transmission apparatus according to an aspect of the present invention is configured to allocate a calculation resource, a storage resource, and a transmission resource to configure a plurality of virtual transmission apparatuses, and to change the amount of resources allocated to each virtual transmission apparatus, When a software failure occurs, a virtualization control unit is provided for minimizing the allocated resource amount of the failed virtual transmission device and increasing the allocated resource amount of other virtual transmission devices.

  According to such an invention, there is an effect of preventing a system down due to a software failure.

  In the transmission apparatus according to an aspect of the present invention, the virtual transmission apparatuses each have different versions of routing software, and when normal, data transmission is performed by the virtual transmission apparatus that retains the latest version of the routing software. When a software failure occurs in a virtual transmission device holding a version of routing software, the amount of resources allocated to the virtual transmission device holding the latest version of routing software is minimized, and other versions of routing software A virtualization control unit that increases the allocated resource amount of the virtual transmission apparatus that holds the wear.

  According to such an invention, there is an effect that software redundancy can be ensured without developing a plurality of pieces of software having the same specification on different development lines.

  In the transmission device according to an aspect of the present invention, the virtual transmission devices each have different versions of routing software, and when normal, data transmission is performed by a virtual transmission device that has the latest version of routing software. When a software failure occurs in a virtual transmission device that holds a new version of routing software, the amount of resources allocated to the virtual transmission device that holds the newest version of routing software is minimized. Increase the amount of resources allocated to the virtual transmission device that holds the old version of routing software, and sequentially allocate resources to the virtual transmission device that holds the old version of routing software until normal operation can be confirmed. It comprises a virtualization control unit which gradually increased.

  According to such an invention, there is an effect that it is possible to operate with the newest version that does not include a bug that causes a failure.

  A transmission device according to an aspect of the present invention includes a failure detection unit that detects a failure in each of the virtual transmission devices, and notifies the virtualization control unit when the failure detection unit detects a failure, and the virtualization The control unit determines that the failure is caused by software if a failure detection is notified from only one virtual transmission device, and if the failure detection is notified from all virtual transmission devices, the failure caused by hardware It is judged that.

  According to this invention, when a failure is detected, there is an effect that it can be determined whether the failure is caused by hardware or software.

  A communication system according to an aspect of the present invention includes a transmission device, and the transmission device communicates only with a virtual transmission device that holds the same version of software in another transmission device, and is used for control. When the virtualization control unit detects a failure, the virtualization control unit notifies the other transmission device using the control virtual transmission device, and notifies the other transmission device of the failure detection. When received, the allocated resource amount of the virtual transmission device holding the failed version of the routing software is minimized, and the allocated resource amount of other virtual transmission devices is increased.

  According to this invention, when a software failure occurs, there is an effect that the operation can be continued by downgrading the routing software of the transmission apparatus of the entire network.

  A communication system according to an embodiment of the present invention includes a transmission device, and the virtual transmission device of the transmission device further includes untransmitted data held in the own device when a failure is detected, having different versions of software. The other virtual transmission device that has transferred to the virtual transmission device and received the untransmitted data transmits the untransmitted data to the other transmission device using its own version of routing software.

  According to this invention, when a software failure occurs, it is possible to continue communication without losing untransmitted data that remains in the virtual transmission apparatus.

  A control method according to an aspect of the present invention includes a step of allocating computing resources, storage resources, and transmission resources to configure a plurality of virtual transmission devices, a step of changing the amount of resources allocated to each virtual transmission device, Including a step of minimizing an allocated resource amount of the failed virtual transmission device and increasing an allocated resource amount of another virtual transmission device when a software failure occurs.

  According to such an invention, there is an effect of preventing a system down due to a software failure.

  How much or how the minimized resource amount is determined may be appropriately determined according to the application. As an example, the minimized resource amount may be determined from the viewpoints of the degree of calculation processing load, the information storage amount, the transmission / reception amount, and the like. For example, the minimized resource amount may be determined from the viewpoint of an operation processing load that can transfer a packet according to a certain reading protocol. For example, the minimized resource amount may be determined from the viewpoint of the information storage amount that can maintain the routing table. For example, the minimized resource amount may be determined from the viewpoint of a transmission / reception amount that can transmit / receive a predetermined control packet (for example, a message indicating a change in the main virtual transmission device). Further, the minimized resource amount may be determined so that the switching time is as short as possible when a certain version of routing software is switched to an older version of software. For example, if an old version of routing software is started for the first time when a failure of a new version occurs, a lot of time is spent switching between the old and new versions. If resources are allocated to an old version of routing software to some extent, the time required for switching can be reduced. Further, the minimized resource amount may be determined from the viewpoint of ensuring that an old version of routing software can operate. This is because, when a failure occurs in a new version of routing software, if it is attempted to check whether the old version of the routing software operates, the time required for switching between the old and new versions becomes longer.

  Several embodiments will be described below, but the division of each embodiment is not essential to the present invention, and two or more embodiments may be used as necessary. Although specific numerical examples will be described to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified.

  The configuration of the communication system according to the first embodiment of the present invention will be described with reference to FIG. The communication system 100 includes a network 101 and a plurality of terminals 102. The network 101 includes a plurality of transmission devices 103. A plurality of terminals are connected to the network 101 wirelessly such as a wired network 101 such as FTTH (Fiber To The Home) or a mobile phone, and they can communicate with each other.

  The configuration of the transmission apparatus 103 according to the present embodiment will be described with reference to FIG. FIG. 2 is a functional block diagram of the transmission apparatus 103 according to the present embodiment. The transmission apparatus 103 includes a virtualization control unit 201, a failure detection unit 203, a routing unit 204, and a network interface unit 205.

  FIG. 3 shows a hardware configuration of the transmission apparatus 103 according to the present embodiment. The transmission device 103 is configured to include a calculation resource 301 such as a CPU, a storage resource 302 such as a memory, and a transmission resource 303 such as a network interface. The virtualization control unit 201 in FIG. 2 is realized by a calculation resource 301 and a storage resource 302. The failure detection units 203a to 203c are realized by the calculation resource 301 and the storage resource 302. The routing units 204a to 204c are realized by the calculation resource 301 and the storage resource 302. The network interface units 205a to 205c are realized by the transmission resource 303. The illustrated resource (resource) is merely an example, and other resources may be used.

  The failure detection unit 203, the routing unit 204, and the network interface unit 205 in FIG. For example, in FIG. 2, the failure detection unit 203 is divided into three failure detection units 203a to 203c. The routing unit 204 is divided into three routing units 204a to 204c. The network interface unit 205 is divided into three network interface units 205a to 205c. The failure detection unit 203a, the routing unit 204a, and the network interface unit 205a constitute a virtual transmission device 202a. Similarly, the virtual transmission device 202b is configured by the failure detection unit 203b, the routing unit 204b, and the network interface unit 205b. Furthermore, the virtual transmission device 202c is configured by the failure detection unit 203c, the routing unit 204c, and the network interface unit 205c. Although three virtual transmission apparatuses are shown in FIG. 2, the number is not limited as long as resources (that is, capabilities) of the failure detection unit 203, the routing unit 204, and the network interface unit 205 allow. Further, there is no limitation on the amount of resources allocated to each virtual transmission apparatus. For example, if the total amount of resources is 100, it is possible to prepare 10 virtual transmission apparatuses with a resource amount of 10.

  The virtualization control unit 201 controls resource allocation of the failure detection unit 203, the routing unit 204, and the network interface unit 205, and controls how the virtual transmission apparatus 202 is configured. The virtualization control unit 201 also controls the amount of resources allocated to each virtual transmission device. The virtualization control unit 201 sets one of the virtual transmission devices as the main virtual transmission device 202x, and in addition to the main virtual transmission device information (information indicating which virtual transmission device is the main, the resource allocation ratio May be included). In this embodiment, many resources are allocated to the main virtual transmission apparatus. The virtualization control unit 201 is configured to pass data received from the terminal 102 or the adjacent transmission device 103 to the network interface unit 205x of the main virtual transmission device 202x.

  Further, the virtualization control unit 201 uses the failure information from each of the failure detection units (202a, 202b, 202c) to determine whether the failure is caused by software or hardware. If there is a failure notification from all the virtual transmission devices, it is determined that there is a failure in the hardware shared by all the virtual transmission devices. If the failure notification is received only from a specific virtual transmission device, it is determined that there is a failure in software unique to the virtual transmission device. However, other techniques for detecting software faults may be used.

  Each of the virtual transmission apparatuses 202a to 202c is configured by receiving resource allocation of the failure detection unit, the routing unit, and the network interface unit, and operates independently of other virtual transmission apparatuses.

  Each of the failure detection units 203a to 203c is configured to detect a failure that has occurred in each virtual transmission apparatus. The failure detection method may be, for example, a method based on Internet Control Message Protocol (ICMP). When detecting the failure, the failure detection units 203a to 203c notify the virtualization control unit 201 of the failure information and transmit a main virtual transmission device change message to the other adjacent transmission devices 103. The main virtual transmission device change message indicating that the main transmission device has been changed includes the version of the routing software of the main virtual transmission device after the change.

  Further, when a certain transmission apparatus receives a main virtual transmission apparatus change message from another transmission apparatus, the failure detection units 203a to 203c notify the virtualization control unit 201 of the failure information and other adjacent transmission devices The main virtual transmission device change message is forwarded to the transmission device 103 (in this way, receiving the main virtual device change message instead of motivating the failure notification from each failure detection unit to the virtualization control unit 201) The content may be notified directly to the virtualization control device 201). However, if the received main virtual transmission device change message has been sent from its own device in the past or has already been received, notification of failure information, transfer of the main virtual transmission device change message, etc. Not done. When a failure is detected or when a main virtual transmission device change message is received, data received and not yet transferred is configured to be transferred to another virtual transmission device of the same transmission device.

  The routing units 204a to 204c transmit and receive control packets through the network interface unit, and perform path control for data transmission (typically specifying a transfer destination of received data). The routing unit holds routing software that performs route control. The routing software follows some routing protocol. The routing protocol may be an existing protocol such as Border Gateway Protocol (BGP) or Open Shortest Path First (OSPF), or another protocol.

  The network interface units 205a to 205c are configured to transmit and receive packets to and from virtual transmission apparatuses on other physical transmission apparatuses.

  The operation of the transmission apparatus according to this embodiment will be described with reference to FIG. 4-11. In this embodiment, the transmission device 103 is divided into a plurality of virtual transmission devices by a virtualization technique. Each virtual transmission apparatus has a different version of routing software installed in the routing unit. In addition, one virtual transmission device among a plurality of virtual transmission devices is used for network control. In the example of FIG. 4, the virtual transmission device 402a is assigned for network control, and the virtual transmission device 402b has installed the first version (ver1) of routing software. The virtual transmission device 402c has the second version (ver2) of routing software installed. The virtual transmission device 402d has the third version (ver3) of routing software installed. For convenience of explanation, the version number is newer as the number is larger, but another designation method may be adopted (in short, it is only necessary to distinguish the old and new version order). In this case, the network control virtual transmission apparatus 402a need only have a function of transmitting and receiving the main virtual transmission apparatus change message, as will be described later. Rather, it is desirable that the virtual transmission device for network control is configured simply without having a complicated function so that a software failure is unlikely to occur. In this embodiment, network control is performed using one of the virtual transmission devices, but as shown in FIG. 5, a network control unit 206 may be prepared independently of the virtual transmission device. In this case, the network control unit 206 is connected to the network control unit 206 of another transmission apparatus, and configures a control network 1101 independent of the network 101 as shown in FIG.

  The size of each of the virtual transmission devices 402a-d shown in FIG. 4 corresponds to the resource allocation amount, and many resources are allocated to ver3 which is the latest version. In FIG. 4, three versions of software of ver1, ver2, and ver3 are used, but the number of virtual transmission apparatuses is not limited as long as the transmission apparatus 103 has resources. However, if the number of virtual transmission devices is large, the consumption of resources increases, so it is desirable to make the number necessary and sufficient.

  Software (especially routing software in this embodiment) is repeatedly upgraded due to bug handling (bug fix), function addition, and the like. When upgrading, usually the old version of the software is uninstalled and the new version of the software is installed. However, in this embodiment, when a new version of software is introduced, the virtualization control unit 401 prepares a new virtual transmission device, and the new version of software is installed in the routing unit of the new virtual transmission device. In this case, the old virtual transmission apparatus in which the old version of software is installed is maintained without being deleted. However, the amount of resources allocated to the old virtual transmission device is reduced. In FIG. 4, when new ver4 software is introduced, the virtualization control unit 401 newly prepares a virtual transmission device 402e and installs the ver4 routing software therein. The virtual transmission device 402b with the oldest version of the routing software is deleted, and the corresponding resources are released. The resource amount allocated to the virtual transmission device 402d having the ver3 routing software is reduced, and the resource amount of the virtual transmission device 402e is set to the maximum. The resulting state is shown in FIG.

  Each virtual transmission device 402 communicates with a virtual transmission device having the same version of software in other transmission devices, but does not communicate with versions having different versions of software. Instead of installing different versions of software, different vendors or development lines can create and install a plurality of software of the same specification. This is because if the vendors and development lines are different, the same bugs are less likely to occur, and an improvement in resistance to software failures can be expected. However, software development costs may increase.

  A detailed operation example will be described with reference to FIG. In this operation example, a software failure has occurred in the transmission apparatus 103b during data transmission from the terminals 102a to 102b. Assume that the transmission apparatus 103 is configured as shown in FIG. Also, the virtual transmission device 402d, which is the main virtual transmission device, uses many resources of the transmission device 103, and normal data transmission / reception is performed using the virtual transmission device 402d. All the virtual transmission devices 402a to 402d are operating independently. The virtual transmission devices 402a to 402c have lower resources than the virtual transmission device 402d, so the capacity is low, but the data transmission itself is possible (the resources are allocated to such an extent that such a minimum operation is possible). Yes.)

  First, the terminal 102a transmits data to the transmission apparatus 103a to which the data is connected (S601 in FIG. 8). As shown in FIG. 1, typically, the data of the terminal 102a reaches the terminal 102b via the transmission devices 103a, 103b and 103c. When the transmission device 103a receives data from the terminal 102a, the virtualization control unit 401 of the transmission device 103a passes the data to the virtual transmission device 402d set as the main virtual transmission device. Upon receiving the data, the routing unit of the virtual transmission device 402d calculates the next transfer destination of the data. The virtual transmission device 402d transmits data to the transmission device 103b which is the next transfer destination (S602).

  When the transmission device 103b receives the data, the virtualization control unit 401 of the transmission device 103b passes the data to the virtual transmission device 402d set as the main virtual transmission device. In this embodiment, some kind of software failure has occurred in the transmission apparatus 103b. Therefore, the failure detection unit of the virtual transmission device 402d detects such a software failure (S603).

  The operation (S604 to S605) of the transmission device 103b when the failure detection unit of the virtual transmission device 402d detects a failure will be described with reference to FIG. When the failure detection unit of the virtual transmission device 402d of the transmission device 103b detects a failure, the virtualization control unit 401 is notified that a failure has occurred (S801 in FIG. 9). Upon receiving the notification of the failure, the virtualization control unit 401 confirms the failure status of the other virtual transmission devices 402a to 402c. When it can be confirmed that a failure has occurred only in the virtual transmission device 402d, the virtualization control device 401 determines that the failure is a software failure. In this case, the virtual transmission device 402c that holds the software of the version (ver2) immediately before the software version (ver3) of the virtual transmission device 402d becomes the main virtual transmission device (S802). On the other hand, the virtualization control device 401 reduces the resource amount allocated to the virtual transmission device 402d and increases the resource amount allocated to the virtual transmission device 402c (S803). As a result, the transmission apparatus 103b looks as shown in FIG. In this way, the main virtual transmission device is changed from 402d to 402c.

  In addition, when it is determined that a failure has occurred in all of the plurality of virtual transmission apparatuses and the failure is caused by hardware, it cannot be avoided as described above. In this case, conventional techniques such as duplexing may be used in combination.

  Next, data that has been received by the main virtual transmission apparatus 402d but has not yet been transferred is transferred from the virtual transmission apparatus 402d to 402c (S804). These data are transferred by the virtual transmission device 402c. Further, the main virtual transmission device change message is transmitted to the adjacent transmission devices 103a, 103c, 103d, and 103e using the virtual transmission device 402a (S805). However, as mentioned in FIG. 5, when the network control unit 206 is provided in the transmission device independently of each virtual transmission device, the network control unit 206 transfers the main virtual device to another transmission device via the control network 1101. A transmission device change message may be transmitted.

  The operation (S606 to S611) when the transmission apparatuses 103a, 103c, 103d, and 103e receive the main virtual transmission apparatus change message will be described with reference to the flowchart of FIG.

  When the transmission apparatuses 103a, 103c, 103d, and 103e receive the main virtual transmission apparatus change message (S901), the main virtual transmission apparatus change message is transmitted by the own apparatus or has already been received. It is determined whether or not there is (S902). If it has been sent or has already been received, the main virtual transmission device change message is discarded and the process ends. When the main virtual transmission device change message is not transmitted by itself but is not already received, the same processing as that of the transmission device 103b is performed. That is, the main virtual transmission apparatus is switched from the current 402d of ver3 to the virtual transmission apparatus 402c that holds the previous version (ver2) of software (S903). Furthermore, the resource amount allocated to the virtual transmission device 402d (ver 3) is reduced, and the resource amount allocated to the virtual transmission device 402c (ver 2) is increased (S904). If there is data that has been received by the virtual transmission device 402d (ver3) but has not yet been transferred, the data is transferred to another virtual transmission device 402c (ver2) of the same transmission device (S905). Then, the main virtual transmission device change message is transferred to another adjacent transmission device (S906). In this way, in all transmission apparatuses in the network, the virtual transmission apparatus 402c having the old version (ver2) of routing software becomes the main virtual transmission apparatus in each transmission apparatus. As described above, it should be noted that in this embodiment, communication is performed only between virtual transmission devices having the same version of the routing protocol.

  If any transmission device detects any software failure for ver2, the main virtual transmission device of each transmission device is set to the virtual transmission device 402b having the routing software of ver1 through the same procedure. The A similar process is repeated until the oldest version held in each transmission apparatus is reached. When normal operation is confirmed with any version of software from the oldest version to the oldest version of the latest version, the flow of FIG. 11 ends. This corresponds to S610 in FIG.

  When the normal operation is confirmed (S610 in FIG. 8), the virtualization control unit 401 of the transmission device 103b transfers the data using the virtual transmission device 402c (in this example, data transmission by the ver2 routing software is performed normally). Assuming it was operational.) The routing unit of the virtual transmission device 402c of the transmission device 103b calculates the next transfer destination of data. The virtual transmission device 402c transmits data to the transmission device 103c which is the next transfer destination (S611). When the transmission device 103c receives the data, the virtualization control unit 401 of the transmission device 103c passes the data to the virtual transmission device 402c set as the main virtual transmission device. Upon receiving the data, the routing unit of the virtual transmission device 402c calculates the next transfer destination of the data. In the case of the network topology as shown in FIG. 1, since the next transfer destination is the destination terminal 102b, the virtual transmission device 402c transmits data to the terminal 102b (S612).

  As described above, even when a software failure occurs, data can be transmitted easily and quickly to a target destination, and the system throughput is not significantly reduced.

  According to the present embodiment, when a software failure occurs, the routing software of the transmission apparatus of the entire network can be downgraded to continue the operation quickly, and data can be transmitted normally even when a software failure occurs. Conventionally, there has been a method in which a plurality of identical hardware is prepared in one transmission apparatus, different versions of routing software are installed in each transmission apparatus, and switching is performed when a failure occurs (hereinafter referred to as a conventional method). Considering the case where 10 software versions are multiplexed, the conventional transmission system requires 10 identical hardware, which is not an efficient solution. In this embodiment, since a plurality of software can be installed in one piece of hardware (transmission device), the same effect can be obtained with one piece of hardware. Further, in addition to software failure, hardware duplication may be performed in order to cope with hardware failure. In this case, in the conventional method, since each hardware having each version of routing software is duplicated, as many as 20 pieces of hardware are required. However, in the transmission apparatus in this embodiment, only two pieces are required. The same effect can be obtained with hardware. Thus, this embodiment is advantageous in that it can cope with a software failure with a very small number of hardware.

  FIG. 12 shows the configuration of a communication system according to the second embodiment of the present invention. The communication system 1300 in the present embodiment is particularly different from the first embodiment in that the management device 1301 is installed in the network 101.

  FIG. 13 shows the configuration of the management device 1301. A management apparatus 1301 according to this embodiment includes a management control unit 1402, a management information storage unit 1403, and a network interface unit 1404.

  The management control unit 1402 is configured to manage the version of the main virtual transmission device of the transmission device in the network 101.

  The management information storage unit 1403 holds a table 1501 as shown in FIG. This table includes identification information (transmission device ID) of the transmission device and items of software versions used in the main virtual transmission device of the transmission device. The management control device 1402 manages the version of the main virtual transmission device set by each transmission device in the network 101 using information stored in the management information storage unit 1403. In FIG. 14, a resource allocation situation as shown in FIG. 7 is assumed.

  The network interface unit 1404 is configured to be connected to and communicate with a virtual transmission device (for example, 402a in FIG. 4) for controlling the transmission device. The network interface unit 1404 has a function of receiving a main virtual transmission apparatus change message from the transmission apparatus and a function of transmitting the main virtual transmission apparatus change message to the transmission apparatus.

  When the management control unit 1402 receives a main virtual transmission device change message from a certain transmission device 103, the management control unit 1402 updates the table 1501 of the management information storage unit 1403. Specifically, the management control unit 1402 changes the main virtual transmission version (for example, ver3) of the transmission apparatus at the transmission source to the version (for example, ver2) specified by the main virtual transmission apparatus change message in the table 1501. change. When the management control unit 1402 receives the main virtual transmission device change message, the management control unit 1402 transmits the main virtual transmission device change message to all the transmission devices other than the transmission device of the transmission source, and rewrites the table 1501. The versions of the main virtual transmission devices of the transmission devices in the network 101 are the same (for example, all versions are changed from ver3 to ver2).

  The transmission apparatus 103 according to the present embodiment has some differences in the functions of the virtual transmission apparatuses 202a to 202c compared to the first embodiment. When a failure is detected in the virtual transmission device, the failure detection units 203a to 203c of the virtual transmission device in the first embodiment notify the virtualization control unit 201 of the failure information and to other adjacent transmission devices The main virtual transmission device change message was sent. However, the failure detection units 203a to 203c of the virtual transmission device according to the present embodiment transmit a main virtual transmission device change message to the management device 1301 in addition to notifying the virtualization control unit 201 of the failure information. .

  Further, the failure detection units 203a to 203c of the virtual transmission device in the first embodiment notify the virtualization control unit 201 of failure information when receiving a main virtual transmission device change message from another transmission device, The main virtual transmission device change message is transferred to another adjacent transmission device. However, the failure detection units 203a to 203c of the virtual transmission device in the present embodiment receive the main virtual transmission device change message from the management device 1301, and notify the virtualization control unit 201 of the failure information. The management device 1301 is also configured to perform path control of the main virtual transmission device change message.

  The operation of the transmission apparatus according to the present embodiment will be described with reference to FIGS. As in the case of the first embodiment, the transmission device 103 is divided into a plurality of virtual transmission devices by a virtualization technique. The routing unit of each virtual transmission apparatus has different versions of routing software installed. In addition, one virtual transmission device among a plurality of virtual transmission devices is used for network control. In the example of FIG. 4, the virtual transmission device 402a is assigned for network control, and the virtual transmission device 402b has installed the first version (ver1) of routing software. The virtual transmission device 402c has the second version (ver2) of routing software installed. The virtual transmission device 402d has the third version (ver3) of routing software installed. For convenience of explanation, the version number is newer as the number is larger, but another designation method may be adopted (in short, it is only necessary to distinguish the old and new version order). In this case, the virtual transmission device 402a for network control need only have a function of transmitting and receiving the main virtual transmission device change message. Rather, it is desirable that the virtual transmission device for network control is configured simply without having a complicated function so that a software failure is unlikely to occur. In this embodiment, network control is performed using one of the virtual transmission devices, but as shown in FIG. 5, a network control unit 206 may be prepared independently of the virtual transmission device. In this case, the network control unit 206 is connected to the network control unit 206 of another transmission apparatus, and configures a control network 1101 independent of the network 101 as shown in FIG.

  The size of each virtual transmission apparatus shown in FIG. 4 corresponds to the resource allocation amount, and many resources are allocated to ver3 which is the latest version. In FIG. 4, three versions of software of ver1, ver2, and ver3 are used, but the number of virtual transmission apparatuses is not limited as long as the transmission apparatus 103 has resources. However, if the number of virtual transmission devices is large, the consumption of resources increases, so it is desirable to make the number necessary and sufficient.

  Software (especially routing software in this embodiment) is repeatedly upgraded due to bug handling (bug fix), function addition, and the like. Usually, the old version of the software is uninstalled and the system is updated by allowing the new version of software to be installed. However, in this embodiment, when a new version of software is introduced, the virtualization control unit 401 prepares a new virtual transmission device, and the new version of software is installed in the routing unit of the new virtual transmission device. In this case, the old virtual transmission apparatus in which the old version of the software is installed is maintained without being uninstalled. However, the amount of resources allocated to the old virtual transmission device is reduced. In FIG. 4, when new ver4 software is introduced, the virtualization control unit 401 newly prepares a virtual transmission device 402e and installs the ver4 routing software therein. The virtual transmission device 402a with the oldest routing software version is deleted, and the corresponding resources are released. The resource amount allocated to the virtual transmission device 402d having the ver3 routing software is reduced, and the resource amount of the virtual transmission device 402e is set to the maximum. The resulting state is shown in FIG.

  Each virtual transmission device 402 communicates with a virtual transmission device having the same version of software in other transmission devices, but does not communicate with versions having different versions of software. Instead of installing different versions of software, different vendors or development lines can create and install a plurality of software of the same specification. This is because if the vendors and development lines are different, the same bugs are less likely to occur, and an improvement in resistance to software failures can be expected. However, software development costs may increase.

  A detailed operation example will be described with reference to FIG. Also in this operation example, a software failure has occurred in the transmission apparatus 103b during data transmission from the terminals 102a to 102b. Assume that the transmission apparatus 103 is configured as shown in FIG. Also, the virtual transmission device 402d, which is the main virtual transmission device, uses many resources of the transmission device 103, and normal data transmission / reception is performed using the virtual transmission device 402d. All the virtual transmission devices 402a to 402d are operating independently. The virtual transmission devices 402a to 402c have lower resources than the virtual transmission device 402d, so the capacity is low, but the data transmission itself is possible (the resources are allocated to such an extent that such a minimum operation is possible). Yes.)

  First, the terminal 102a transmits data to the transmission device 103a (S1501). As shown in FIG. 12, typically, data of the terminal 102a reaches the terminal 102b via the transmission apparatuses 103a, 103b, and 103c. When the transmission device 103a receives data from the terminal 102a, the virtualization control unit 401 of the transmission device 103a passes the data to the virtual transmission device 402d set as the main virtual transmission device. Upon receiving the data, the routing unit of the virtual transmission device 402d calculates the next transfer destination of the data. The virtual transmission device 402d transmits data to the transmission device 103b which is the next transfer destination (S1502).

  When the transmission device 103b receives the data, the virtualization control unit 401 of the transmission device 103b passes the data to the virtual transmission device 402d set as the main virtual transmission device.

  When the transmission device 103b receives the data, the virtualization control unit 401 of the transmission device 103b passes the data to the virtual transmission device 402d set as the main virtual transmission device. In this embodiment, some kind of software failure has occurred in the transmission apparatus 103b. Therefore, the failure detection unit of the virtual transmission device 402d detects such a software failure (S1503).

  The operation (S1504 to S1505) of the transmission device 103b when the failure detection unit of the virtual transmission device 402d detects a failure will be described with reference to FIG. When the failure detection unit of the virtual transmission device 402d of the transmission device 103b detects a failure, the virtualization control unit 401 is notified that a failure has occurred (S801 in FIG. 9). Upon receiving the notification of the failure, the virtualization control unit 401 confirms the failure status of the other virtual transmission devices 402a to 402c. When it can be confirmed that a failure has occurred only in the virtual transmission device 402d, the virtualization control device 401 determines that the failure is a software failure. In this case, the main virtual transmission device is switched to the virtual transmission device 402c that holds the software (ver2) that is the previous version of the software version (ver3) of the virtual transmission device 402d (S802). On the other hand, the virtualization control device 401 reduces the resource amount allocated to the virtual transmission device 402d and increases the resource amount allocated to the virtual transmission device 402c (S803). As a result, the transmission apparatus 103b looks as shown in FIG. In this way, the main virtual transmission device is changed from 402d to 402c.

  In addition, when it is determined that a failure has occurred in all of the plurality of virtual transmission apparatuses and the failure is caused by hardware, it cannot be avoided as described above. In this case, conventional techniques such as duplexing may be used in combination.

  Next, the data that has been received by the virtual transmission device 402d but has not yet been transferred is transferred from the virtual transmission device 402d to the 402c (S804). These data are transferred by the virtual transmission device 402c. Further, the main virtual transmission device change message is transmitted to the adjacent transmission devices 103a, 103c, 103d, and 103e using the virtual transmission device 402a (S805). However, as mentioned in FIG. 5, when the network control unit 206 is provided in the transmission device independently of each virtual transmission device, the network control unit 206 transfers the main virtual device to another transmission device via the control network 1101. A transmission device change message may be transmitted.

  The management device 1301 that has received the main virtual transmission device change message updates the management table 1501. In the table 1501 of the management information storage unit 1403, the software version of the main virtual transmission device of the transmission source device 103b of the main virtual transmission device change message is changed to the version specified in the main virtual transmission device change message. (S1506 in FIG. 16). Then, the main virtual transmission device change message is transmitted to all transmission devices (103a, 103c, 103d, 103e in the illustrated example) other than the transmission device 103b that is the transmission source (S1507), and all the tables 1501 are rewritten. It is done.

  Upon receiving the main virtual transmission device change message, the transmission devices 103a, 103c, 103d, and 103e change the main virtual transmission device in the same manner as the transmission device 103b. Specifically, the main virtual transmission device is switched from the virtual transmission device 402d, which is the current main virtual transmission device, to the virtual transmission device 402c that holds the version of the routing software indicated by the main virtual transmission device change message (S1508). ~ S1511). In this case, the resource amount assigned to the virtual transmission device 402d is reduced, and the resource amount assigned to the virtual transmission device 402c is increased. If there is data that has been received by the main virtual transmission apparatus 402d before switching but has not yet been transferred, the data is transferred to a new main virtual transmission apparatus in the same transmission apparatus. Thus, in all transmission apparatuses in the network, the virtual transmission apparatus having an old version of routing software becomes the main virtual transmission apparatus.

  If any transmission device detects any software failure for ver2, the main virtual transmission device of each transmission device is set to the virtual transmission device 402b having the routing software of ver1 through the same procedure. The A similar process is repeated until the oldest version held in each transmission apparatus is reached. When normal operation is confirmed with any version of software from the oldest version to the oldest version of the latest version, the flow proceeds to the next step.

  When the normal operation is confirmed (S1512), the virtualization control unit 401 of the transmission device 103b transfers the data using the virtual transmission device 402c (in this example, data transmission by the routing software of ver2 can operate normally). I'm assuming it was.) The routing unit of the virtual transmission device 402c of the transmission device 103b calculates the next transfer destination of data. The virtual transmission device 402c transmits data to the transmission device 103c which is the next transfer destination (S1513). When the transmission device 103c receives the data, the virtualization control unit 401 of the transmission device 103c passes the data to the virtual transmission device 402c set as the main virtual transmission device. Upon receiving the data, the routing unit of the virtual transmission device 402c calculates the next transfer destination of the data. In the case of the network topology as shown in FIG. 12, since the next transfer destination is the destination terminal 102b, the virtual transmission device 402c transmits data to the terminal 102b (S1514).

  Thus, even when a software failure occurs, data can be transmitted normally. Since the management device 1301 is prepared separately according to the present embodiment, in addition to the effects of the first embodiment, the version of the main virtual transmission device of the transmission device in the network 101 is centrally managed by the management device 1301. can do. In addition, when a failure occurs in a plurality of versions of software, the management device 1301 can match them, and an appropriate version that can be used can be quickly specified to the transmission device.

  Next, a third embodiment of the present invention will be described. Although this embodiment includes a management device as in the second embodiment, the functions thereof are slightly different.

  Also in this embodiment, the management apparatus is configured as shown in FIG. The management device 1301 includes a management control unit 1402, a management information storage unit 1403, and a network interface unit 1404.

  The management control unit 1402 is configured to manage the version of the main virtual transmission device of the transmission device in the network 101.

  The management information storage unit 1403 holds a table 1801 as shown in FIG. This table is very different from that of the second embodiment. The table includes transmission device identification information (transmission device ID), software versions currently used in the main virtual transmission device of each transmission device, and a plurality of software versions held in each transmission device. The management control device 1402 manages the version of the main virtual transmission device set by each transmission device in the network 101 using information stored in the management information storage unit 1403.

  The network interface unit 1404 is configured to be connected to and communicate with a virtual transmission device (for example, 402a in FIG. 4) for controlling the transmission device. The network interface unit 1404 has a function of receiving a main virtual transmission apparatus change message from the transmission apparatus and a function of transmitting the main virtual transmission apparatus change message to the transmission apparatus.

  When the management apparatus receives the main virtual transmission apparatus change message, the management apparatus transfers the main virtual transmission apparatus change message to all transmission apparatuses other than the transmission apparatus that is the transmission source. The management device maintains the same version of the main virtual transmission device of the transmission device in the network 101 by rewriting the table 1801. The management device refers to the stored version list in the table 1801, and when any transmission device does not hold the version indicated by the received main virtual transmission device change message, the main virtual transmission indicating a version different from that version It is also possible to create and send a device change message. For example, it is assumed that the transmission apparatus 103b creates a main virtual transmission apparatus change message for requesting to change the software version of the main virtual transmission apparatus from ver4 to ver3 and transmits it to the management apparatus. When the table 1801 is configured as shown in FIG. 17, the software of ver3 is not held (not supported) in the transmission apparatus 103d. In this case, it is impossible to perform communication using version ver3 software between all the transmission apparatuses. Therefore, the management apparatus of the present embodiment creates a main virtual transmission apparatus change message for requesting to change the software version of the main virtual transmission apparatus from ver4 to ver2 with reference to the retained version list in the table 1801. Sent to a transmission device (including source). This is because the ver2 version is maintained by all transmission devices.

  According to the present embodiment, it is possible to easily and quickly make an appropriate change of the software version (change from ver4 to ver2). According to the present embodiment, in addition to the effects of the first and second embodiments, even when a group of software versions (software sets) held in each transmission apparatus are different, they are held in common. By appropriately instructing the current version, the version of the main virtual transmission device of each transmission device can be kept the same easily and quickly.

  Although the present invention has been described above with reference to specific embodiments, each embodiment is merely illustrative, and those skilled in the art will appreciate various variations, modifications, alternatives, substitutions, and the like. Let's go. Although specific numerical examples have been described in order to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The division of each embodiment is not essential to the present invention, and two or more embodiments may be used as necessary. For convenience of explanation, an apparatus according to an embodiment of the present invention has been described using a functional block diagram, but such an apparatus may be realized by hardware, software, or a combination thereof. The present invention is not limited to the above embodiments, and various modifications, modifications, alternatives, substitutions, and the like are included in the present invention without departing from the spirit of the present invention.

It is a figure showing the structure of the communication system which concerns on 1st Example of this invention. It is a functional block diagram showing the structure of the transmission apparatus which concerns on the 1st Example of this invention. It is a figure which shows the hardware constitutions of the transmission apparatus which concerns on the 1st Example of this invention. It is a functional block diagram showing the structure of the transmission apparatus which concerns on the 1st Example of this invention. It is a functional block diagram showing the structure of the transmission apparatus which concerns on the 1st Example of this invention. It is a figure showing the structure of the communication system which concerns on 1st Example of this invention. It is a functional block diagram showing the structure of the transmission apparatus which concerns on the 1st Example of this invention. It is a sequence diagram which shows operation | movement of the system which concerns on the 1st Example of this invention. It is a flowchart which shows operation | movement of the transmission apparatus which concerns on 1st Example of this invention. It is a functional block diagram showing the structure of the transmission apparatus which concerns on the 1st Example of this invention. It is a flowchart which shows operation | movement of the transmission apparatus which concerns on 1st Example of this invention. It is a figure showing the structure of the communication system which concerns on the 2nd Example of this invention. It is a functional block diagram showing the structure of the control apparatus which concerns on the 2nd Example of this invention. It is a figure showing the structure of the table which the control apparatus which concerns on 2nd Example of this invention hold | maintains. It is a figure showing the structure of the communication system which concerns on the 2nd Example of this invention. It is a sequence diagram which shows operation | movement of the system which concerns on the 2nd Example of this invention. It is a figure showing the structure of the table which the control apparatus which concerns on the 3rd Example of this invention hold | maintains.

Explanation of symbols

100 communication system
101 network
102 terminals
103 Transmission equipment
201 Virtualization control unit
202 Virtual transmission equipment
203 Fault detection unit
204 Routing part
205 Network interface
301 computational resources
302 Accumulated resources
303 Transmission resources
401 Virtualization control unit
402 Virtual transmission equipment
1101 Control network
1300 Communication system
1301 Management device
1402 Management control unit
1403 Management information storage
1404 Network interface
1501 tables

Claims (10)

A transmission device for transmitting signals between communication nodes of a network,
Means for receiving a signal;
Means for determining a transfer destination of the received signal according to a predetermined protocol;
Means for transmitting the received signal to the transfer destination;
The transmission device is logically divided into a plurality of virtual transmission devices,
A first virtual transmission device of the plurality of virtual transmission devices operates with a first version of routing software;
A second virtual transmission device of the plurality of virtual transmission devices operates with second routing software newer than the first version;
The transmission apparatus in which the quantitative relationship between the signal processing resources allocated to the first and second virtual transmission apparatuses is reversed before and after a software failure occurs in routing by the second routing software. The transmission device includes a virtual control unit that controls a plurality of virtual transmission devices,
Each of the plurality of virtual transmission devices has a failure detection unit that detects the presence or absence of a failure and notifies at least the virtual control unit that a failure has occurred,
The virtual control unit determines whether the failure is a hardware failure or a software failure according to whether or not all of the plurality of virtual transmission apparatuses report that there is a failure. The transmission device described.   The transmission apparatus according to claim 1 or 2, wherein any one of the plurality of virtual transmission apparatuses functions as a main virtual transmission apparatus and can use more signal processing resources than other virtual transmission apparatuses.   The message indicating that the main virtual transmission apparatus is changed due to a software failure occurring in the second virtual transmission apparatus is notified to a predetermined communication node in the network. 4. The transmission apparatus according to any one of items 1 to 3.   One virtual transmission device among the plurality of virtual transmission devices is used for receiving a message indicating that the main virtual transmission device has been changed at the communication node from a communication node other than the transmission device. Item 5. The transmission device according to Item 4.   The transmission apparatus according to claim 1, wherein after a software failure occurs in the second virtual transmission apparatus, the amount of signal processing resources allocated to the second virtual transmission apparatus is minimized. .   7. The transmission apparatus according to claim 6, wherein the signal processing resource amount to be minimized is a minimum necessary level for transmitting and receiving packets in accordance with routing software of a virtual transmission apparatus in which a software failure has occurred. The transmission apparatus is logically divided into a plurality of virtual transmission apparatuses, and a first virtual transmission apparatus of the plurality of virtual transmission apparatuses operates with a first version of routing software, and the plurality of virtual transmission apparatuses The second virtual transmission apparatus is a method for transmitting a signal between communication nodes of a network by a transmission apparatus in a communication system that is operated by second routing software that is newer than the first version. And
Receiving a signal from a communication node in the transmission apparatus;
Determining a communication node to which the signal is transferred;
Transmitting the signal to the transfer destination;
The quantitative relationship between the signal processing resources allocated to the first and second virtual transmission apparatuses is reversed before and after a software failure occurs in routing by the second routing software. Transmission equipment. A communication system having a network including a plurality of transmission devices, each transmission device,
Means for receiving a signal;
Means for determining a transfer destination of the received signal according to a predetermined protocol;
Means for transmitting the received signal to the transfer destination;
And the transmission device is logically divided into a plurality of virtual transmission devices,
A first virtual transmission device of the plurality of virtual transmission devices operates with a first version of routing software;
A second virtual transmission device of the plurality of virtual transmission devices operates with second routing software newer than the first version;
A communication system in which the quantitative relationship between signal processing resources allocated to the first and second virtual transmission apparatuses is reversed before and after a software failure occurs in routing by the second routing software. The communication system further includes a management device separately from the plurality of transmission devices,
In each transmission device, any one of a plurality of virtual transmission devices functions as a main virtual transmission device, and the main virtual transmission device can use more signal processing resources than other virtual transmission devices,
The management device receives a message indicating that the main virtual transmission device has been changed due to a software failure occurring in the second virtual transmission device of any of the transmission devices, and receives another transmission The communication system according to claim 9, wherein the communication system is transferred to a device.

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