JP2010087936A - Communication apparatus, communication system employing same and operation control method of communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a communication apparatus capable of continuing processing without cutting a communication path in communication. <P>SOLUTION: The communication apparatus includes a plurality of user planes 102-104 of redundant configuration including a user data processing function and a control plane 105 provided in common for the plurality of user planes and including a control function. The control plane 105 includes a holding section 205 for holding information required for maintaining a communication path 109 between each of the user planes 102-104 and mobile terminals 100, 101 and if any failure occurs on the active user plane, the information required for maintaining the communication path of such a faulty user plane is succeeded to any reserve user plane. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication device, a communication system using the communication device, and an operation control method for the communication device, and more particularly to a redundancy system in the communication system.

  In an RNC (Radio Network Controller) of a radio access network in a mobile communication system standardized by 3GPP (Third Generation Partnership Project), a control plane for processing control signals and user data are processed. There is a user plane.

  Here, referring to Patent Document 1, a so-called C / U separation configuration in which the control (C) plane and the user (U) plane are separated, and a plurality of users having a redundant configuration with respect to one control plane. A system with a plane installed is disclosed. In this case, if one of the multiple user planes is used as a standby system and the remaining user planes are used as active systems, and congestion occurs in the active system, a part of the processing is switched over to the standby system and taken over. It has become.

  Further, referring to Patent Document 2, a system in which a redundant configuration of first and second protocol processing units (corresponding to a user plane) is provided for one control unit (corresponding to a control plane) in the RNC is disclosed. Has been. In this configuration, when it is necessary to switch the processing from the first protocol processing unit to the second protocol processing unit, the secret information currently being communicated is transferred from the first protocol processing unit to the second protocol processing unit. So that communication can be continued.

JP 2004-048209 A JP 2005-347983 A

  In a communication system in which a plurality of user planes having a redundant configuration is provided for one control plane as described above, a case where one of the active user planes becomes a failure will be considered. In this case, in the technique of the above-mentioned patent document, the processing is taken over to the spare or the second user plane. However, in order to maintain the currently communicating line, the information for that is used as the current working fault. It is necessary to take over from the user plane to the spare or the second user plane.

  However, since the current user plane is a failure, there is a great risk that information for maintaining the communication path is also destroyed and lost, so the line cannot be maintained and is disconnected. Therefore, it is necessary to re-establish the communication path again.

  An object of the present invention is to provide a communication device capable of continuing communication without disconnecting a communication path during communication, a communication system using the communication device, and an operation control method for the communication device.

  A communication apparatus according to the present invention includes a plurality of redundant user planes having a user data processing function, and a control plane having a control function provided in common to the plurality of user planes, and the control plane includes the user plane A holding unit for holding information necessary for maintaining a communication path between each of the planes and the mobile terminal is provided. When a failure occurs in the current user plane, information necessary for maintaining the communication path of the failed user plane is stored. It is characterized by taking over to a spare user plane.

  A communication control method according to the present invention is an operation control method for a communication apparatus including a plurality of redundant user planes having a user data processing function and a control plane provided in common to the plurality of user planes and having a control function. In the control plane, a step of holding information necessary for maintaining a communication path between each of the user planes and a mobile terminal, and a communication path of the failed user plane when a failure occurs in the active user plane And the step of handing over information necessary for maintenance to a spare user plane.

  A communication system according to the present invention includes the communication device described above.

  A program according to the present invention causes a computer to execute an operation of a communication apparatus including a plurality of redundant user planes having a user data processing function and a control plane provided in common to the plurality of user planes and having a control function. A process for controlling the control plane to hold information necessary for maintaining a communication path between each of the user planes and a mobile terminal, and when a failure occurs in an active user plane, And a process of handing over information necessary for maintaining the communication path of the failed user plane to a spare user plane.

  According to the present invention, information for maintaining the communication path with the mobile terminal of the active user plane is always held in the control plane, and when the active user plane becomes a failure, Since the information for maintaining the communication path of the changed user plane is taken over to the standby user plane, there is an effect that the maintenance of the communication path with the mobile terminal can be continued in the standby user plane.

  In the following, embodiments of the present invention will be described. Prior to that, the principle of the present invention will be described with reference to FIG. 1 for better understanding of the present invention. FIG. 1 is a schematic system configuration diagram for explaining the principle of the present invention, and shows only a portion related to the present invention.

  Referring to FIG. 1, the present invention includes mobile terminals 100 and 101 and a communication device 108. The communication device 108 has the above-described C / U separation configuration and the user plane has a redundant configuration. . That is, the communication apparatus 108 has a plurality of user planes 102 to 104 and a control plane 105 common to the user planes 102 to 104. This control plane 105 performs processing of various control signals and management of a plurality of user planes 102-104.

  Each of the mobile terminals 100 and 101 makes a communication path establishment request to the user plane of the communication apparatus 108 when communicating with a not-shown opposite apparatus. At this time, the mobile terminals 100 and 101 are equally distributed to a plurality of user planes. A communication path establishment request is made. For example, the communication path is established by selecting a connection-destination user plane by the round robin method.

  When a mobile terminal establishes a communication path with one active user plane and a failure occurs in the user plane, information necessary for maintaining the communication path managed by the failed user plane is It will be destroyed. As a result, the communication path is disconnected, and it is necessary to start establishment of the communication path again.

  Therefore, in the present invention, information necessary for maintaining the currently established communication path is managed by the state management table 205 provided in the control plane 105, and when a failure occurs in the user plane, the user plane is moved. Information necessary for maintaining the communication path established between the terminal and the terminal is read from the state management table 205 of the control plane 105, and is taken over to another spare user plane. This makes it possible to continue maintaining the communication path with the mobile terminal in the standby user plane.

  Note that the information necessary for maintaining the communication path is clarified in an embodiment described later.

  Next, an embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic system configuration diagram to which the embodiment of the present invention is applied. In FIG. 1 and FIG. 2, equivalent parts are denoted by the same reference numerals. The configuration shown in FIG. 2 is a network configuration for providing a mobile communication network service of a mobile phone via a wireless local area network (WLAN) standardized by 3GPP.

  This system includes a plurality of mobile terminals 100, 101, an IPsec (IP (Internet Protocol) security protocol) terminating device 108, an application server 106, and an authentication server 107.

  The IPsec terminator 108 is a tunnel terminator of IPsec SA (Security Association) 109 that is stretched between the own device and the mobile terminals 100 and 101. Since a public line such as the Internet is used for the network between the mobile terminal and the IPsec terminator, it is necessary to ensure secure communication by this IPsec SA109. For this purpose, the IPsec termination device 108 is a device provided at the boundary between a network (mobile communication network) in the mobile communication carrier and the Internet.

  The user data encrypted by IPsec in the mobile terminal is decrypted by the IPsec terminator 108 and transferred to the application server 106 of the mobile communication network provided ahead. Further, the IPsec terminator 108 accesses an authentication server (AAA: Authentication Authorization Accounting) 107 in order to perform authentication processing when establishing an IPsec SA.

  The application server 106 is a device that processes user data transmitted from a mobile terminal. For example, the application server 106 is a device that performs processing conforming to the SIP protocol (Session Initiation Protocol) for communication control used in an IP phone or the like. . The authentication server 107 is a server that manages the connection state (subscriber information) of the mobile terminal, and executes the authentication process of the mobile terminal during the IKE (Internet Key Exchange) process.

  One of the device configurations for realizing the IPsec terminal device 108 is the C / U separation structure as described above, and this device adopts this C / U separation structure and has a control signal processing function. The control plane is separated from the user plane having a user data transfer processing function. The user plane is provided with N + 1 redundant devices (N is an integer equal to or greater than 1) 102 to 104 (2 + 1 in this example), and a common control for the plurality of user planes 102 to 104 is provided. It is assumed that a plane 105 is provided.

  The user planes 102 to 104 in the IPsec termination apparatus 108 serve as IPsec tunnel termination gateways. Further, the user planes 102 to 104 update the latest information of SPD (Security Policy Database) and SAD (Security Association Database), which are database information necessary for maintaining the IPsec SA 109, to the state management table 202 to 104, respectively. Each of them is held at 204.

  Each information of SAD and SPD held by each user plane is updated when IPsec SA is established by IKE processing. User data encrypted by IPsec is encrypted by referring to and updating each information of SAD and SPD. Each information of SPD and SAD is linked by SPI (Security Parameter Index) given to each IPsec SA.

  In addition, a sequence number stored in the SAD is a value that is updated each time an IPsec packet encryption process is performed. This sequence number is a number for indicating the order of the encrypted packets.

  The control plane 105 manages the user planes 102 to 104, and performs access to the authentication server 107, which is performed when the IPsec SA is established, on behalf of the user plane. The control plane 105 is assumed to hold the latest information held in the state management tables 202 to 204 of the user planes 102 to 104 in the state management table 205.

  When each of the mobile terminals 100 and 101 establishes IPsec SAs for the user planes 102 to 104 of the IPsec terminator 108, the mobile terminals 100 and 101 evenly spread the IPsec SAs for N + 1 user planes. For example, when a mobile terminal obtains an IP address of an IPsec termination device using DNS (Domain Name System), it selects a connection-destination user plane in a round-robin manner for N + 1 user planes. Realized.

  Next, the operation of the embodiment of the present invention will be described. FIG. 3 is a connection diagram of the control plane 105 and the user planes 102 to 104 in FIG. 2 and the contents of the state management tables 205 and 202 to 204 held in these.

  Each state management table 202 to 204 managed in each of the user planes 102 to 104 has an entry of IPsec SA units (SPI units), and SAD information (including a sequence number) is provided for each of these entries. And SPD information.

  The state management table 205 managed by the control plane 105 is No. It has a plurality of entries indicated by 1, 2, 3,. Each entry includes SAD information (including sequence number) and SPD information of each IPsec SA unit (SPI unit) of all user planes, as well as a user plane number indicating which user plane the information is, Operation status information indicating which state the user plane is in the active system / standby system / failure system, and an IP address allocated to the user plane are held.

  FIG. 4 is a sequence diagram showing an operation procedure of the N + 1 redundancy system shown in FIG. 2. The normal operation will be described with reference to FIGS. The numbers of the user planes 102 to 104 are # 1 to # 3, respectively.

  Assume that one mobile terminal 100 establishes IPsec SA through the user plane 102 (# 1) (506, 507). At this time, an authentication sequence to the authentication server (AAA) 107 is also performed through the control plane 105 (not shown in the sequence diagram). At this time, in the state management table 202 of the user plane 102 (# 1), the entry information corresponding to the established IPsec SA is recorded as SPI information 1, SAD information SAD1, and SPD information SPD1. .

  After establishing the IPsec SA, the user plane 102 (# 1) transfers the SPD information and SAD information of the established IPsec SA to the control plane 105 (508). The transferred SPD information and SAD information are stored in the No. of the status management table 205 of the control plane 105. 1 entry.

  Similarly, another mobile terminal 101 establishes an IPsec SA via the user plane 103 (# 2), and this IPsec SA information is stored in the No. of the status management table 205 of the control plane 105. Suppose that it is recorded in the second entry (509 to 511).

  Here, it is assumed that the mobile terminal 100 transmits user data to the application server 106 using IPsec SA (512). At this time, the user plane 102 (# 1) uses its own state management table 202 to decrypt the user data encrypted by IPsec (513). Thereafter, the user plane 102 (# 1) transfers the updated sequence number to the control plane 105 (514), and transmits user data to the application server 106 (515).

  The control plane 105 that has received the updated sequence number receives the No. of its own state management table 205. Update the sequence number of one entry.

  Similarly, when the mobile terminal 101 transmits user data to the application server 106 via the user plane 103 (# 2) using IPsec SA, the same operation as described above is performed (516 to 519). Up to this point, the sequence of the normal state and the state of the state management table of FIG. 3 are obtained.

  Next, with reference to the sequence diagram of FIG. 5 and FIGS. 6 and 7, the operation when a failure occurs in one active user plane and the takeover to the standby user plane will be described. Here, it is assumed that the user plane 102 (# 1) has a device failure (606). At this time, the user plane 102 (# 1) deletes its own IP address so that a new IPsec SA cannot be established (607).

  Subsequently, the user plane 102 (# 1) transmits a user plane device failure notification to the control plane 105 (609). Finally, the user plane 102 (# 1) is restarted, and the contents of the held state management table 202 are also discarded (609).

  The control plane 105 that has received the device failure notification from the user plane 102 (# 1) sets the entry corresponding to the user plane number # 1 in its state management table 205 as No. 1. By setting to 3, the operation system user plane is switched from the user plane 102 (# 1) to the user plane 104 (# 3) (610). Here, no. The user plane number of the 1 entry is changed from # 1 to # 3.

  Subsequently, the control plane 105 changes the user plane number of the entry corresponding to the standby user plane 104 (# 3) in its operation state management table 205 to # 1, and changes the operation state to failure. . Here, no. In the entry 3, these change processes are performed. Through this series of processes, the user plane 104 (# 3) which is a standby system is used as a new operational system.

  The control plane 105 that has changed the contents of the state management table 205 has the SPD information of all SPIs originally held by the user plane 102 (# 1) with respect to the user plane 104 (# 3) that is a new operational system. , SAD information (including sequence number) and IP address are transferred (611). Here, No. of the status management table 205 of the control plane 105 is displayed. The contents of the 1 entry are transferred to the user plane 104 (# 3).

  The user plane 104 (# 3) that received the SPD information, SAD information (including the sequence number), and IP address of all the SPIs originally held by the user plane 102 (# 1) manages the contents of itself. This is held in the table 204 (see 204 in FIG. 6). As a result, the contents of the state management table 102 of the failed user plane 102 (# 1) are all transferred to the user plane 104 (# 3), and the IPsec SA stretched by the user plane 102 (# 1) is Maintained. By this series of processing, the handover is completed (612).

  It is assumed that after the takeover processing is completed, the mobile terminal 100 transmits user data to the application server using IPsec SA (613). Since the IP address A of the user plane in which the mobile terminal 100 has established the IPsec SA has been taken over by the user plane 104 (# 3), the user plane 104 (# 3) receives the IPsec-encrypted data. Become.

  The data encrypted by IPsec is decrypted by the user plane 104 (# 3) using the state management table 204 of the user plane 104 (614). Thereafter, the user plane 102 (# 1) transfers the updated sequence number to the control plane 105 (615), and transmits user data to the application server 106 (616). Upon receiving the updated sequence number, the control plane 105 receives the No. in its own state management table 205. Update the sequence number of one entry.

  Also, when the faulty user plane 102 (# 1) is recovered from the fault, No. in the status management table 205 of the control plane 105 is set. 3 is used as a backup system, the user plane 102 (# 1) is used as a new backup system (see FIG. 7).

  As described above, the mobile terminal 100 can continue the processing without disconnecting the application layer session during communication while maintaining the IPsec SA.

  In other words, in the above embodiment, information for maintaining IPsec SAs of a plurality of active user planes is always held in the control plane, and when one of the active user planes becomes a failure, Information necessary for maintaining the IPsec SA of the operation user plane that has failed is configured to be taken over from the control plane to the standby user plane. Therefore, it is possible to maintain the IPsec SA with the mobile terminal in the standby user plane, and as a result, it is possible to continue the processing without disconnecting the application layer session during communication.

  In the above embodiment, the example applied to the IPsec terminator has been described. However, the present invention is not limited to this. In general, the present invention is widely applied to communication devices having a C / U separation structure and a redundant configuration of the U (user) plane. It is clear that we can do it. The operation sequences shown in FIGS. 4 and 5 can of course be configured such that the procedure is stored in advance in a recording medium as a program and is read and executed by a computer.

It is the schematic for demonstrating the principle of this invention. 1 is a schematic system configuration diagram showing an embodiment of the present invention. It is a figure which shows the example of the content of the state management table at the time of normal in embodiment of this invention. It is an operation | movement sequence diagram at the normal time in embodiment of this invention. It is an operation | movement sequence diagram at the time of the failure generation in embodiment of this invention. It is a figure which shows the example of the content of the state management table at the time of failure occurrence in embodiment of this invention. It is a figure which shows the example of the content of the state management table after the failure recovery in embodiment of this invention.

Explanation of symbols

100, 101 Mobile terminal 102-104 User plane
105 Control plane
106 Application server
107 Authentication server
108 Communication device (IPsec terminator)
109 communication path (IPsec SA)
202 to 205 Status management table

Claims (11)

Including a plurality of redundant user planes having a user data processing function, and a control plane having a control function provided in common to the plurality of user planes,
The control plane has a holding unit that holds information necessary for maintaining a communication path between each of the user planes and a mobile terminal. When a failure occurs in the current user plane, the communication path of the failed user plane A communication device characterized in that information necessary for maintenance of data is handed over to a spare user plane.   The communication apparatus according to claim 1, wherein the communication path is taken over by the spare user plane. The communication device is an IPsec (security protocol) termination device, and the communication path is an IPsec SA (Security Association) that needs to ensure secure communication,
3. The communication apparatus according to claim 1, wherein the information is SAD (Security Association Database) information and SPD (Security Policy Database) information.   4. The communication apparatus according to claim 3, wherein the SAD information includes a sequence number of a packet when user data is encrypted based on the IPsec.   The communication apparatus according to claim 4, wherein the sequence number is constantly updated and held in the holding unit of the control plane.   A communication system comprising the communication device according to claim 1. An operation control method for a communication apparatus including a plurality of redundant user planes having a user data processing function and a control plane having a control function provided in common to the plurality of user planes,
In the control plane,
A step of holding information necessary for maintaining a communication path between each of the user planes and the mobile terminal, and a reserve of information necessary for maintaining the communication path of the failed user plane when a failure occurs in the current user plane; To the user plane. The communication device is an IPsec (security protocol) termination device, and the communication path is an IPsec SA (Security Association) that needs to ensure secure communication,
8. The method according to claim 7, wherein the information is SAD (Security Association Database) information and SPD (Security Policy Database) information.   9. The method according to claim 8, wherein the SAD information includes a sequence number of a packet when user data is encrypted based on the IPsec.   The method according to claim 9, wherein the sequence number is held in the holding unit of the control plane while being constantly updated. A program for causing a computer to execute an operation of a communication device including a plurality of redundant user planes having a user data processing function and a control plane provided in common to the plurality of user planes and having a control function. ,
Processing for controlling the control plane to hold information necessary for maintaining a communication path between each of the user planes and a mobile terminal, and a communication path of the failed user plane when a failure occurs in an active user plane And a step of transferring information necessary for maintenance to a spare user plane.

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