WO2009139306A1

WO2009139306A1 - Communication system and redundant configuration management method

Info

Publication number: WO2009139306A1
Application number: PCT/JP2009/058548
Authority: WO
Inventors: 裕司鈴木
Original assignee: 日本電気株式会社
Priority date: 2008-05-15
Filing date: 2009-05-01
Publication date: 2009-11-19
Also published as: TW200952399A; JP2009278436A

Abstract

A redundant device stores configuration information, including IP addresses and routing information used for transferring user data, and session information for each device in use. Then, in the event that a problem occurs with any of the devices in use, the redundant device continues the transfer of user data in place of said device in use based on the stored configuration information and the session information corresponding to the device in use where the problem occurred.

Description

Communication system and redundant configuration management method

The present invention relates to a communication system having an N + α redundant configuration and a redundant configuration management method thereof.

Next-generation high-speed wireless communication adopting Mobile WiMAX (Worldwide Interoperability for Microwave Access) etc. has high mobility for mobile terminals using Mobile IP (Internet Protocol) technology standardized by the Internet Engineering Task Force (IETF). Service is provided.

Mobile WiMAX is also expected to provide services to large-scale users who own a large number of mobile terminals in order to support wireless communication in a wide range of wireless areas and high-speed movement. Therefore, Home Agent compatible with mobile WiMAX, which manages location information for each mobile terminal, and relays user data transmitted and received between the mobile terminal and the network such as the Internet, includes a large number of movements used by large-scale users. A device configuration that manages location information for each terminal and realizes large-capacity data transfer is desired.

In addition, since Mobile WiMAX provides connection services to the Internet etc. even to mobile terminals moving at high speed as described above, Home Agent is required to have high reliability capable of always providing stable services. Furthermore, for Home Agent, an inexpensive system configuration that can flexibly cope with an increase in the number of users and an increase in traffic volume is desired.

Therefore, a Home Agent compatible with mobile WiMAX is often constructed by combining a plurality of PC (Personal Computer) -based user data transfer devices operating under a general-purpose OS such as Linux.

In general, reliable systems that can be operated continuously even if a failure occurs are N (N is a positive integer) number of current (ACT) devices and α (α is a positive integer) number of redundant This can be realized by an N + α redundant configuration provided with an SBY) system device. In particular, in a communication system requiring higher reliability, a one-to-one redundant configuration in which one SBY system device is deployed corresponding to one ACT system device is adopted.

In a system of such an N + α redundant configuration, if a failure occurs in any of the N ACT system devices (hereinafter referred to as ACT system devices) operating at all times, an SBY system device (hereinafter SBY system devices) ) Will continue to provide services on behalf of the failed ACT device. The system of the one-to-one redundant configuration and the system of the N + 1 redundant configuration where α = 1 are described in, for example, JP-A-2005-333243.

In the case where the Home Agent compatible with mobile WiMAX has the above-described N + α redundant configuration, in the ACT system device, session registration / deletion dynamically occurs in the mobile IP network at the time of operation, so the session state changes as needed. Therefore, it has conventionally been considered impossible for the SBY system device to rapidly take over the session state of the ACT system device in which the failure has occurred.

Furthermore, when a failure occurs in any of the ACT devices, the SBY device identifies an ACT device (hereinafter referred to as a failure device) in which the failure has occurred, and is used by the failure device to provide a service. Further, setting information such as an IP address, routing information, and information on a terminal group to be registered in a session is acquired, the setting information is registered in the own apparatus, and switching is made to an ACT system that operates on behalf of the faulty apparatus.

Therefore, it takes a long time for the SBY system apparatus to take over the operation of the failure apparatus, and there is a problem that the interruption time of the connection service to the Internet etc. provided to the user becomes long. In particular, when the communication system such as Home Agent is configured with a plurality of PC-based user data transfer devices operating on a general-purpose OS such as Linux, the information communication between user data transfer devices also uses a general-purpose IP protocol As a result, the SBY system device takes a long time to acquire setting information including a large amount of IP addresses and routing information used by the fault device. A configuration may be considered in which dedicated hardware is provided to share setting information, session information, and the like between the ACT system device and the SBY system device, but this increases the cost of the communication system.

In a communication system that requires users to provide a high-capacity data transfer service, such as Home Agent compatible with Mobile WiMAX, and an inexpensive configuration is required, service interruption at the time of failure occurs without increasing costs. There is a need for a fast switching method from SBY devices to ACT devices with session handover that minimizes time.

Therefore, an object of the present invention is to provide a communication system capable of minimizing the service interruption time when a failure occurs without causing an increase in cost.

In order to achieve the above object, the communication system of the present invention comprises a plurality of constantly operating devices operating at all times, and at least one redundant device replacing the currently used device in which a failure has occurred. A plurality of user data transfer devices for transferring user data generated in each session;
A database in which setting information including an IP address used for transferring the user data and routing information is stored for each of the user data transfer devices;
A management device that manages setting information for each of the user data transfer devices;
Have
The redundant device is
It is configured to hold setting information of all of the currently used apparatuses and session information indicating the state of the session.

On the other hand, the redundant configuration management method according to the present invention includes, for each user, a plurality of active devices operating at all times, and at least one redundant device replacing the active device in which a failure has occurred. A redundant configuration management method in a communication system comprising a plurality of user data transfer devices for transferring user data generated in a session, comprising:
The redundant system device holds setting information including an IP address and routing information used for transfer of the user data, and session information indicating a state of a session for each of the active systems.
When a failure occurs in any of the currently used devices, the redundant device is held by its own device based on the setting information and session information corresponding to the currently used device where the failure has occurred. It is a method of continuing the transfer of the user data in place of the currently used device in which the failure has occurred.

FIG. 1 is a block diagram showing a configuration example of a communication system of the present invention. FIG. 2 is a sequence diagram showing an operation example of the communication system shown in FIG.

The present invention will now be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example of a communication system of the present invention.

As shown in FIG. 1, the communication system 1 of the present invention realizes, for example, a Home Agent compatible with mobile WiMAX, and N + 1 user data transfer devices 2 for transferring user data generated in a session for each user. and ₁ to _{2 N + 1,} monitors the status of each user data transfer device ₂ 1 _{- 2 N + 1,} and the management unit 3 that manages the setting information of the user data transfer device ₂ ₁ every _{2 N + 1,} the user data transfer device _{2 1} And a database 4 in which setting information for each of _{2N + 1} is stored. The N + 1 user data transfer devices 2 ₁ to 2 _{N + 1} and the management device 3 are connected to each other via the layer 2 switch (L2SW) 5. The user data transfer devices 2 ₁ to 2 _{N + 1} are connected to the mobile IP network via the layer 2 switch 5.

The management device 3 monitors the states of the system data setting device 31 which transmits the setting information stored in the database 4 to each of the user data transfer devices 2 ₁ to 2 _{N + 1} at the time of system activation, and the user data transfer devices 2 ₁ to 2 _{N + 1.} And a device management unit 32 that detects the presence or absence of a failure.

For example, a computer such as a workstation server is used in the management device 3, and information such as configuration information of the communication system 1 and an IP address used for information communication in the communication system 1 are registered in advance. The configuration information of the communication system 1 includes information indicating the number of user data transfer devices 2 ₁ to 2 _{N + 1} , the user data transfer device operating as an ACT system device, and the device number of the user data transfer device operating as an SBY system device. Contains.

When each user data transfer device in the communication system 1 is activated, the management device 3 transmits corresponding setting information to the user data transfer devices 2 ₁ to 2 _{N + 1} and all the user data transfer devices 2 ₁ to 2 _It monitors the operation of _{N + 1} and determines whether or not a failure occurs.

The user data transfer devices 2 ₁ to 2 _{N + 1} are PC-based communication devices that operate on a general-purpose OS (Operating System) such as Linux, and store processing devices including a CPU and programs and data for operating the CPU. Storage device. In the user data transfer devices 2 ₁ to 2 _{N + 1} , N user data transfer devices 2 ₁ to 2 _N are used as ACT devices, and one user data transfer device 2 _{N + 1} is used as an SBY device. Hereinafter, the term ACT device refers to the user data transfer devices 2 ₁ to 2 _N, and the term SBY refers to the user data transfer device 2 _{N + 1} .

For example, the operator of the communication system 1 assigns the above-described apparatus-specific setting information to the ACT system apparatus. The setting information for each ACT system device is stored in the database 4 connected to the management device 3 and is transmitted from the system setting unit 31 provided in the management device 3 to each ACT system device at the time of system startup.

When the ACT device receives setting information from the management device 3 after device activation, the ACT device provides communication service (connection service to the Internet, etc.) to the mobile terminal of the user based on the setting information.

By the way, since it is unclear which ACT system device is to be replaced by the SBY system device, the SBY system device provided in the conventional communication system does not have the setting information necessary for providing the service even after the start of the device. The SBY system apparatus included in the communication system 1 of the present invention acquires setting information of N ACT system apparatuses from the management apparatus 3 at the time of apparatus startup and holds the setting information.

When provision of service to the user is started by the communication system 1 shown in FIG. 1 and registration of location information is requested from the mobile terminal of the user, the ACT system device performs the user processing by the mobile terminal simultaneously with registration processing of the location information. Create a session to use for data transfer. At this time, each ACT device transmits session information indicating the state of the session of the own device to the SBY device.

The SBY system apparatus has a memory area for storing session information for each of N ACT system apparatuses, receives session information corresponding to the state of each session from each ACT system apparatus, and corresponds to the ACT system apparatus Session information in association with each other. As a result, the SBY system apparatus matches the session information of each ACT system apparatus held by the SBY system with the session state of each ACT system apparatus.

The management device 3 monitors the operation state of the user data transfer devices 2 ₁ to 2 _{N + 1} , and when a failure occurs in any ACT system device, the device management unit 32 detects the occurrence of the failure.

When the management device 3 detects a failure that has occurred in the ACT system device, the management device 3 instructs the SBY system device to switch from the SBY system to the ACT system, which includes information on the device number of the ACT system device where the failure has occurred. While transmitting the switching notification, the operation of the ACT related device where the failure has occurred is reset and disconnected from the communication system.

When receiving the switching notification from the management device, the SBY device registers the setting information of the failed ACT device with the own device, validates the session information corresponding to the ACT device, and provides the service to the user. Start.

Here, when the SBY system apparatus switches to the ACT system apparatus, if the SBY system apparatus registers setting information in its own apparatus using an API (Application Program Interface) provided by the OS, it is based on the setting information. It takes time for the operation to become effective. Therefore, in the present invention, the SBY system apparatus stores setting information of all ACT system apparatuses in a kernel area which is a memory area used by an OS (Operating System). In this way, for example, the setting information of the ACT system device specified by only one command specifying the device number can be reflected on the own device. Therefore, the time until the operation based on the setting information becomes effective is shortened.

When switching to an ACT system device, the SBY system device of the present invention does not need to acquire setting information and session information from another device, and is specified from the management device 3 using only information held by the own device. The operation of the ACT system device can be taken over. Therefore, the SBY device can quickly take over the operation of the ACT device specified by the management device 3 and the state of the session, so that the service interruption time at the time of failure occurrence is minimized, and the user fails Provide services that are not aware of the occurrence of

When the SBY system device is activated later than the ACT system device, the SBY system device can not acquire session information related to the session created by the ACT system device before activation. Therefore, the session information held by the SBY system device may not match the session state of the ACT system device.

However, in the mobile IP protocol, location information of each mobile terminal is periodically transmitted, and session information indicating update of a session is periodically sent to the SBY device from an ACT device providing a service to the mobile terminal. Is sent. Therefore, even if the session information held by the SBY apparatus immediately after startup does not match the session state of the ACT apparatus, the SBY apparatus does not match the position information transmitted from the mobile terminal. The state of the session of the ACT system device providing the service to the mobile terminal can be matched with the session information corresponding to the ACT system device.

Next, the operation of the communication system of the present invention will be described using FIG.

FIG. 2 is a sequence diagram showing an operation example of the communication system shown in FIG.

As shown in FIG. 2, first, when the communication system is activated, the management device 3 starts the state monitoring of the (N + 1) each user data transfer devices by the state management unit 32.

Subsequently, the management apparatus 3 sequentially transmits setting information corresponding to each of the ACT system devices by the system setting unit 31. At this time, the management device 3 also transmits setting information of each ACT system device to the SBY system device, and the SBY system device associates the ACT system device with the corresponding setting information and stores it in the memory area of the own device. .

The ACT system device having received the setting information registers the setting information in the own device and starts service for the user. Upon receiving a session start request from a user, an ACT-based device that has started the service creates a session used by the user (mobile terminal), and transfers user data of the user. Also, when the session update signal (position information update signal) is received from the user, the session state is updated. Every time a session is created or updated, the ACT device transmits session information indicating the state of the session to the SBY device.

The SBY device stores the session information received from the ACT device in association with the device number of the ACT device.

The SBY device updates the held session information for each ACT device based on the session information transmitted from the ACT device. As a result, the SBY system device matches the session information held for each ACT system device with the state of the session of each ACT system device.

When the deletion of the session is requested by the user, the ACT device deletes the session and transmits session information indicating the deletion of the session to the SBY device. When the SBY system device receives session information indicating deletion of a session, the SBY system device deletes session information corresponding to the ACT system device.

Here, when a failure occurs in an arbitrary ACT device (the user data transfer device # 1 in the example shown in FIG. 2), the management device 3 detects the occurrence of the failure by the device management unit 32, and the SBY device A switching notification is sent to instruct switching from the SBY system to the ACT system including the device number of the faulty device. Also, the management device 3 forcibly resets the operation of the faulty device by the device management unit 32 in order to physically disconnect the faulty device from the communication system.

The SBY device receiving the switching notification from the management device 3 fetches the setting information of the ACT device specified from the management device 3 held in the kernel area into the own device based on the device number included in the switching notification. The session information of the ACT system device is validated, and a switching completion notification indicating the completion of switching from the SBY system to the ACT system is transmitted to the management device 3.

Thereafter, the old SBY system apparatus newly switched to the ACT system starts service for the user using the same setting information (IP address and routing information) and session information as the failed apparatus operating as the ACT system. In addition, since creation, update, and deletion of sessions are also executed by the old SBY system device that has newly transitioned to the ACT system, transfer processing of user data using an existing session created by the faulty device continues without interruption. it can.

In the present invention, the session information is transmitted from the ACT system device to the SBY system device when a session is created or updated, so in a large-scale communication system that accommodates a large number of users, the SBY from a large number of ACT system devices. Session information is simultaneously transmitted to the system device, which may cause congestion in the SBY system device.

As a technique for avoiding such a problem, there is replication in which session information is transmitted from an ACT system device to an SBY system device at predetermined cycles that do not depend on the occurrence of a session or update. However, when session information is transmitted from all ACT devices to SBY devices, congestion occurs in the SBY devices as described above. Therefore, it is preferable to limit the number of ACT devices that simultaneously transmit session information, and to divide the session information of all the ACT devices into a plurality of times for transmission to the SBY device. Alternatively, the management device instructs each ACT system device to transmit timing of session information so that the replication cycle of each ACT system device does not overlap, and each ACT system device transmits session information according to the instruction from the management device. It is also good.

In the above description, the features of the present invention are illustrated by taking the communication system of N + 1 redundant configuration as an example, but the present invention can be applied to a communication system of N + α redundant configuration including a plurality of SBY devices (α units). However, in this case, since the ACT device needs to transmit session information to a plurality of SBY devices, the processing load of the ACT device may increase by the number of SBY devices.

According to the present invention, since the SBY system apparatus holds setting information for each ACT system apparatus in the kernel area, the SBY system apparatus can be switched at high speed to an ACT system apparatus serving as a substitute for a failure apparatus. In addition, the SBY device fails as the SBY device maintains the session information of the ACT device by updating the session information of the ACT device as triggered by the creation or update of the session in the ACT device. You can take over the session you were creating quickly. Therefore, the interruption time of the service at the time of the occurrence of the failure can be minimized, and the service can be provided without the user being aware of the occurrence of the failure.

Further, according to the present invention, an inexpensive communication system consisting of PC-based communication devices can be constructed, and communication service can be continued with one SBY device even if a failure occurs in any of a plurality of ACT devices. A telecommunications carrier that provides telecommunications services can reduce capital investment.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. The configuration and details of the present invention can be variously modified within the scope of the present invention and understood by those skilled in the art.

This application claims priority based on Japanese Patent Application No. 2008-128423 filed on May 15, 2008, the entire disclosure of which is incorporated herein.

Claims

A plurality of devices for transferring user data generated in each session of a user, comprising a plurality of active devices operating at all times and at least one redundant device replacing the active device in which a failure has occurred. A user data transfer device,
A database in which setting information including an IP address used for transferring the user data and routing information is stored for each of the user data transfer devices;
A management device that manages setting information for each of the user data transfer devices;
Have
The redundant device is
A communication system holding setting information of all the active devices and session information indicating the state of the session.
The management device is
At the time of activation of the user data transfer device, the setting information corresponding to each device is transmitted to the device of the active system, and the setting information of each device of the active system is transmitted to the device of the redundant system. The communication system according to claim 1.
The device for current use is
The session information is transmitted to the redundant system device in response to creation or update of the session in its own device,
The redundant device is
The communication system according to claim 1 or 2, wherein session information received from each active system device is stored in association with each active system device.
A plurality of devices for transferring user data generated in each session of a user, comprising a plurality of active devices operating at all times and at least one redundant device replacing the active device in which a failure has occurred. A redundant configuration management method in a communication system comprising a user data transfer device, comprising:
The redundant system device holds setting information including an IP address and routing information used for transfer of the user data, and session information indicating a state of a session for each of the active systems.
When a failure occurs in any of the currently used devices, the redundant device is held by its own device based on the setting information and session information corresponding to the currently used device where the failure has occurred. The redundant configuration management method continues the transfer of the user data in place of the currently used device in which the failure has occurred.
At the time of activation of the user data transfer device, the setting information corresponding to each device is transmitted to the device of the active system, and the setting information of each device of the active system is transmitted to the device of the redundant system. A redundant configuration management method according to claim 4.
The device of the current use system transmits the session information to the device of the redundant system upon generation or update of the session in the own device.
The redundant configuration management method according to claim 4 or 5, wherein the redundant system device holds session information received from each active system device in association with each active system device.
A user data transfer apparatus for transferring user data generated in a session for each user, which is an alternative apparatus to an always-on system, which is an active system.
A storage device for holding setting information including an IP address and routing information used for transfer of the user data, and session information indicating a state of a session for each device of the active system;
When a failure occurs in any of the devices for current use, the current use for which the failure has occurred based on setting information and session information corresponding to the device for current use in which the failure has occurred, held in the storage device A processing unit that continues the transfer of the user data on behalf of a system unit;
User data transfer device having:
8. The user data transfer apparatus according to claim 7, wherein the memory area holding setting information of the currently used apparatus is a kernel area.