JP2011010187A - Communication network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce hardware and the number of IP addresses for monitoring.SOLUTION: A control apparatus for monitoring a device to be monitored includes: an active system server including a first control unit in an active state and a first alive monitor in a standby state for monitoring whether the device to be monitored is alive; a standby system server including a second control unit in the standby state and a second alive monitor in the active state for monitoring whether the device to be monitored is alive; and a packet distribution device which is connected with the device to be monitored via a first communication network and connected with each of the servers via a second communication network, translates a second transmission source address, in the second communication network, of a packet from the second alive monitor toward the device to be monitored into a first transmission source address in the first communication network for transmission to the device to be monitored, translates a transmission destination address of a response packet into the second transmission source address for transmission to the standby system server.

Description

  The present invention relates to a communication system network, and more particularly, to a communication network system that performs life / death monitoring of an application using a higher-level protocol by a redundant device.

  High reliability is required for a system that always provides services, and various maintenance devices exist. The life and death monitoring device, which is a type of maintenance device, is a device that monitors the operating status of each device that is constantly operating in the communication system network. The basic operation is to confirm the vitality of the monitored object by sending a signal to the monitored object and receiving the response. In addition, if there is some abnormality (monitoring target is down, signal does not reach due to network failure, etc.) and the response cannot be received, the system maintenance person is notified.

  A Ping response is used to monitor the life and death of devices connected to the IP network (see, for example, Patent Document 1).

  The Ping response is used as an echo request used in the Internet Control Message Protocol (ICMP) and a communication confirmation method in an IP network using the echo response. Advantages of using the Ping response include high versatility. In a system configured with an IP network, most devices support the network layer protocol ICMP referred to in the OSI model, so the device can be monitored by a Ping response without special settings for the monitoring target. You can also check network communication.

  Further, in order to improve reliability in a system that always provides a service, it is a frequently performed means to make important devices in the system redundant (for example, Patent Document 2). For devices with asynchronous redundancy, the active server and standby server are one: one redundant configuration (1 + 1 redundant configuration) or N: one redundant configuration (N + 1 redundant configuration) The active server indicates a server whose main function is in the Active state (ACT), and the standby server indicates a server whose main function is in the Standby state (SBY).

JP 2007-336221 A Japanese Patent Laid-Open No. 8-186619

  In recent years, life and death monitoring capable of monitoring up to the application level has been demanded. However, in the alive monitoring by the Ping response, even if the operation status of the device can be confirmed, the operation status of the application on the device cannot be confirmed.

  Since life-and-death monitoring at the application level cannot use a general-purpose method such as a Ping response, it is necessary to construct a life-and-death monitoring application for each application used by the system. As a result, it is often the case that a device dedicated to alive monitoring is installed in the system.

  In addition, in an asynchronously redundant apparatus, there is a problem that the standby server is not used and hardware resources cannot be effectively utilized unless a failure occurs in the active server.

  The present invention has been made to solve the above-described problems, and it is possible to reduce the number of hardware resources and external IP addresses without impairing the function of a redundantly configured device. An object is to obtain a communication network system that can be used.

  The communication network system of the present invention includes a monitoring target device that executes an application, a first control unit in an active state, and a first alive monitoring unit in a standby state that monitors the monitoring target device on an application level. A second server (standby) including a first server (active server) including the second control unit in the standby state and a second life / death monitoring unit in the active state that monitors the monitoring target device at the application level. System server) and the monitoring target device via the first communication network, connected to the first server and the second server via the second communication network, and the second of the second server The second transmission source address in the second communication network of the first packet directed to the monitoring target device from the alive monitoring unit is sent to the first communication network. The first transmission source address is converted and transmitted to the monitoring target device, and the transmission destination address of the response packet corresponding to the first packet from the monitoring target device is converted to the second transmission source address and second. A control device having a packet distribution device for transmitting to the server.

  In another desirable aspect of the present invention, the packet distribution device has an ID table for storing the second transmission source address in response to reception of the first packet, and receives the packet via the first communication network. The second packet is sent to the first server and the second server according to whether or not the transmission destination address of the second packet including the response packet is stored in the ID table as the second transmission source address. Is selectively transmitted to either of these.

  According to still another preferred aspect of the present invention, in response to the transition of the first control unit of the first server from the active state to the standby state, the second server activates the second control unit from the standby state. The first life and death monitoring unit is changed from the standby state to the active state, and the first server is changed from the standby state to the active state.

  According to the present invention, a computer used as a conventional life and death monitoring apparatus is unnecessary by causing a standby server to perform life and death monitoring. Also, by sharing the IP address assigned to the alive monitoring device with the IP address of the standby server, the number of IP addresses to be used can be reduced.

It is an example of a communication network system. It is an example of a structure of a base station control apparatus. It is a structural example of a packet distribution apparatus. It is a structural example of an active server. It is a structural example of a standby server. It is a structural example of an accounting / authentication server. It is a structural example of a home agent. It is a structural example of a maintenance center. It is a sequence diagram for alive monitoring. It is a sequence diagram when a response message is not received in alive monitoring. It is a structural example of a monitoring table. It is a structural example of an ID table. It is a flowchart of a packet distribution process. It is a sequence diagram of redundant switching operation. It is a message processing sequence diagram accompanying redundancy switching.

  FIG. 1 is an example of a communication network system. The communication network system includes a radio base station 20, a base station controller 30, a charging / authentication server 40, a home agent 50 connected to the core network 70, and a maintenance center 60 that maintains the base station 20 and the base station controller 30. .

  The base station 20 forms a wireless communication area (cell) corresponding to the wireless transmission power and communicates wirelessly with the wireless terminal 10 located in the wireless communication area.

  The authentication / billing server 40 is connected to the base station controller 30, and authenticates the radio terminal 10 via the base station controller 30 when the radio terminal 10 establishes communication with the core network 70.

  The home agent 50 is connected to a core network 70 such as the Internet or a public communication network, for example, relays a transmission packet from the wireless terminal 10 to the core network 70, and receives a packet addressed to the wireless terminal 10 received from the core network 70. Relay to the radio terminal 10 via the base station control device 30 and the base station 20.

  The maintenance center 60 is connected to the base station 20 and the base station control device 30, and performs maintenance and management of the base station 20 and the base station control device 30.

  Here, in order to simplify the drawing, one base station 20 and one base station control device 30 are arranged, but there are a plurality of base station control devices 30, and each base station control device 30 has a plurality of base station control devices 30. The base station 20 can be controlled. Similarly, a plurality of accounting / authentication servers 40 and home agents 50 may exist.

  FIG. 2 is a configuration example of the base station control device 30. The base station control device 30 includes an active server 31, a standby server 32, and a packet distribution device 33.

  FIG. 3 is a configuration example of the packet distribution device 33. The packet distribution device 33 includes a processor 330, a communication interface 1 (331) with the base station 20, a communication interface 2 (332) with the active server 31, a communication interface 3 (333) with the standby server 32, billing / authentication It has a communication interface 4 (334) with the server 40 and the home agent 50, a communication interface 5 (335) with the maintenance center 60, and a memory 336, which are connected by a bus. On the memory 336, a packet transfer processing unit 337, a message buffer 338, and an ID table 600 are arranged.

  4 is a configuration example of the active server 31. The active server 31 includes a processor 310, a communication interface 311 with the packet distribution device 33, an HDD 312, and a memory 313, which are connected by a bus. The memory 313 includes a call control unit 314, an alive monitoring unit 315 that monitors the standby server 32, a failure monitoring unit 316, and a monitoring table 500A.

  FIG. 5 is a configuration example of the standby server 32. When the standby server 32 forms, for example, 1 + 1 redundancy with the active server 31, the same block configuration diagram is used except for the processing units arranged on the memory. This embodiment can also be applied to a case where N + 1 redundancy is configured by N active servers 31 and one standby server 32.

  The standby server 32 includes a processor 320, a communication interface 321 with the packet distribution device 32, an HDD 322, and a memory 323, which are connected by a bus. In the memory 323, a call control unit 324, an alive monitoring unit 325 that monitors the active server 31, a failure monitoring unit 326, and a monitoring table 500B are arranged.

FIG. 6 is a configuration example of the accounting / authentication server 40. The accounting / authentication server 40 includes a communication interface 41 with the base station control device 30, a memory 42, a processor 44, and an HDD 45, which are connected by a bus. On the memory 42, a processing program of the accounting / authentication unit 43 is arranged. ,
FIG. 7 is a configuration example of the home agent 50. The home agent 50 includes a communication interface 1 (51) with the base station control device 30, a memory 52, a communication interface 2 (54) with the core network 70, a processor 55, and an HDD 56, which are connected by a bus. . In the memory 52, an application processing program of the home agent 50 is arranged. Here, this processing program is called a main processing 53.

  FIG. 8 is a configuration example of the maintenance center 60. A communication interface 61 between the base station 20 and the base station control device 30, a memory 62, a processor 64, an HDD 65, and an input / output device 67 are connected, and these are connected by a bus.

  FIG. 9 is a sequence diagram in which the life and death monitoring unit 325 of the standby server 32 performs life and death monitoring (application execution and life monitoring) on the main process 53 in the home agent 50 at the application level. The alive monitoring unit 325 uses an upper protocol MIPv4 (Mobile Internet Protocol v4).

  A monitoring table 500B used by the standby server 32 in this alive monitoring sequence will be described. FIG. 11 shows a configuration example of the monitoring table 500. The monitoring table 500B of the standby server 32 and the monitoring table 500A of the active server 31 have the same configuration. The monitoring table 500B includes the monitoring type 501 that is the type of the monitoring target, the number 502 that identifies the monitoring target, the status 503 of the monitoring target, and the IP address of the monitoring target. In the IP address 504 column, predetermined data is registered in advance. The monitoring table 500A of the active server 31 is not used when the active server 31 is in the operating state, but is used after the active server 31 is switched to the standby state and the standby server 32 is switched to the operating state.

  The alive monitoring unit 325 transmits an MIPv4 specification Registration Request message to the IP address of the home agent 50 (IP address of the communication interface 1 (51)) (SQ01). The Registration Request message includes the internal IP address of the standby server 32 (IP address of the communication interface 321) as the source IP address, the IP address of the home agent 50 as the destination IP address, and a time stamp as an example of Identification. .

  A Registration Request message (packet) from the alive monitoring unit 325 of the standby server 32 passes through the packet distribution device 33. In other words, the Registration Request message is relayed by distributing the destination by the packet distribution device 33. FIG. 12 is a configuration example of an ID table 600 used when the packet distribution device 33 relays a message or response packet. The ID table 600 includes columns for a communication protocol 601, an identification 602, a communication interface 603, an internal IP address 604 that is a transmission source IP address, and an external IP address 605 that is an IP address of the packet distribution device 33.

  The packet distribution device 33 that has received the Registration Request message from the alive monitoring unit 325 of the standby server 32 identifies the received communication interface. Since it is the communication interface 3 (333) connected to the standby server 32, the received Registration Request message is analyzed, and each of the communication protocol 600, Identification 601, communication interface 603, and internal IP address 604 of the transmission source of the ID table 600 is analyzed. In the column, register the analysis result as a new record. Subsequently, the transmission source IP address of the Registration Request message is rewritten to the external IP address of the communication interface 4 (334) of the packet distribution device 33 (SQ02), and transferred to the home agent 50 (SQ03).

  The main process 53 of the home agent 50 analyzes the received Registration Request message and generates a Registration Reply message (packet) (SQ04). The generated Registration Reply message is transmitted to the packet distribution device 32 (SQ05). In the Registration Reply message, the external IP address of the communication interface 4 (334) of the packet distribution device 33 as the transmission destination IP address, and the external IP address of the home agent 50 as the transmission source IP address (IP address of the communication interface 1 (51)) The same value as the Identification of the Registration Request message is included as the Identification of the MIPv4 specification.

  The packet distribution device 32 analyzes the received Registration Reply message, and searches the ID table 600 using the protocol that received the Registration Reply message and the Identification included in the Registration Reply message as keys (SQ06). If there is a record with matching Identification, rewrite the Registration Reply destination IP address to the value of the internal IP address 604 of the searched record, and send a Registration Reply message from the communication interface shown in the communication interface 603 of the searched record. Transfer (SQ07). Delete the searched record in the ID table 600. Here, the Registration Reply message uses the destination IP address as the IP address of the communication interface 321 of the standby server 32, and the alive monitoring unit of the standby server 32 that has transmitted the Registration Request message via the communication interface 3 (333). Forwarded to 325.

  The alive monitoring unit 325 that has received the Registration Reply message from the packet distribution device 33 determines that the home agent 50 that is the transmission destination of the Registration Request message is operating normally, and sets the monitoring target state 503 in the monitoring table 500B to `` “Normal” is stored (SQ08).

  FIG. 10 is a simplified sequence diagram when the alive monitoring unit 325 of the standby server 32 does not receive the corresponding Registration Reply message (response message) within a predetermined time after transmitting the Registration Request message.

  If the alive monitoring unit 325 does not receive the corresponding Registration Reply message within a predetermined time (timeout time) T after sending the Registration Request message (SQ01, SQ03: equivalent to SQ01 to SQ03 in FIG. 9), it times out. The Registration Request message is retransmitted (SQ13, SQ14). If the Registration Reply message is not received even after repeating a predetermined number of retransmissions, it is determined that the home agent 50 that transmitted the Registration Request message as a monitoring target or its main process 53 is not operating normally, and the monitoring table 500B “Abnormal” is stored in the status 503 of the monitoring target (SQ15). The life and death monitoring unit 325 of the standby server 32 transmits a TRAP (SNMPv2) message to the maintenance center 60 via the packet distribution device 33 (SQ16, SQ17), and the home agent 50 is normally sent to the maintenance center 60. Notify that it is not working.

  FIG. 13 is a flowchart showing a packet distribution process 700 when the packet distribution device 33 receives a message such as a Registration Request message.

  When the packet distribution device 33 receives the message (step 701), the transmission source of the message is either internal (active server 31 and standby server 32) or external (base) based on the type of communication interface that received the message. Station 20, authentication / billing server 40, home agent 50 and maintenance center 60) (step 702). Internal / external indicates internal / external of the base station control device 30.

  If the message source is internal, it is determined whether the message destination IP address is an internal IP address or an external IP address (step 703). The internal IP address / external IP address is an IP address used for communication corresponding to the inside / outside of the base station controller 30.

  If the message destination IP address is an external IP address, it is determined whether the source IP address is the internal IP address of the standby server 32 (step 704).

  When a message from the internal IP address of the standby server 32 is sent from the inside to the outside, the protocol type, Identification, communication interface, source internal IP address of the received message, destination An external IP address is registered (step 705).

  The internal IP address of the transmission source is rewritten to the external IP address of the communication interface of the packet distribution device 33 that transmits the message (step 706), and the message is transmitted (step 707).

  In step 704, when a message is sent from the active server 31 to the outside (when the transmission source IP address is not the internal IP address of the standby server 32), information is not registered in the ID table 600, but the transmission source IP The address is rewritten to the external IP address (step 706), and the message is transmitted (step 707).

  In step 703, if the transmission destination is internal, the message is transferred without rewriting the original IP address of the transmission destination / transmission source because the message is from inside to inside.

In step 702, if the transmission source is external, the message is analyzed based on the protocol type, and the identification is extracted in correspondence with the protocol type. The record of the ID table 600 is searched using the combination of the protocol type and the identification as a key, and it is determined whether the corresponding record is registered (step 708).
If registered, it can be determined that the message is a reply message (response) to the message sent from the alive monitoring unit 325 of the standby server 32 to the outside. The transmission destination IP address of the message is rewritten to the internal IP address 604 indicating the standby server 31B (step 709). The corresponding record in the ID table 600 is deleted (step 710), and a message is transmitted (step 707).

  In step 708, if the identification of the received message is not registered in the ID table 600, it is determined that the received message is not a response to the message from the alive monitoring unit 325 of the standby server 32, and the destination IP address is The internal IP address indicating the active server 31 on which the call control unit 314 is operating is rewritten (step 711), and a message is transmitted (step 707).

  FIG. 14 is a sequence diagram of the redundant switching operation. Redundant switching is switching the active server 31 to the standby system and the standby server 32 to the active system. However, along with the redundancy switching, the alive monitoring unit 315 of the active server 31 changes from the standby state (SBY) to the active state (ACT), and the alive monitoring unit 325 of the standby server 32 changes from the active state (ACT) to the standby state ( SBY).

  Here, redundant switching when the failure monitoring unit 316 of the active server 31 detects a failure will be described as an example. The failure monitoring unit 316 that has detected the failure transmits a switching request to the call control unit 314 and the packet distribution device 33 of the active server 31 (SQ20, SQ30). The packet distribution device 33 that has received the switching request transfers the switching request to the alive monitoring unit 325 of the standby server 32, and receives a message not related to the switching received until the switching is completed, as a message buffer. Accumulate in 338 (SQ31).

  Upon receiving the switching request, the call control unit 314 transfers the call control data necessary for operation possessed by the call control unit 314 of the active server 31 to the call control unit 324 of the standby server 32 (SQ21), and from ACT to SBY (SQ22). Further, a switching request is transmitted to the call control unit 324 of the standby server 32 via the packet distribution device 33 (SQ23, SQ24). The call control unit 324 that has received the switching request makes a transition from SBY to ACT (SQ25). The call control unit 324 that has become ACT transmits a switching completion notification to the packet distribution device 33 (SQ26), and the packet distribution device 33 transfers the switching completion notification to the call control unit 314 (SQ27).

  On the other hand, the alive monitoring unit 325 of the standby server 32 that has received the switching request transmits a data transfer request to the monitoring table 500B (SQ32), and transfers the monitoring information of the monitoring table 500B to the monitoring table 500A (SQ33). The alive monitoring unit 325 receives the data transfer completion notification from the monitoring table 500B (SQ34), and transitions from ACT to SBY (SQ35). Although the monitoring table 500B has been described as performing data transfer, a processing program for notifying the data transfer of the monitoring table 500B and the completion of data transfer is actually prepared. The alive monitoring unit 325 transmits a state transition completion notification to the alive monitoring unit 315 of the active server 31 via the packet distribution device 33 (SQ36, SQ37). The alive monitoring unit 315 of the active server 31 that has received the state transition completion notification transitions from SBY to ACT (SQ38). The alive monitoring unit 315 that has become ACT transmits a switching completion notification to the packet distribution device 33 (SQ39), and the packet distribution device 33 transfers the switching completion notification to the alive monitoring unit 325 (SQ40).

  The packet distribution device 33 that has received the switching completion notification from both the call control unit 324 and the alive monitoring unit 315 receives the communication interface 2 (332) and the communication interface stored in the communication interface 603 of each record existing in the ID table 600. 3 (333) is replaced, and the internal IP address corresponding to this replacement is also replaced (SQ50). After updating the ID table 600, a switch completion notification is transmitted to the failure monitoring unit 316 (SQ51). After redundancy switching is completed, the message stored in the message buffer 338 during the switching operation is processed.

  FIG. 15 is a diagram illustrating an example of a message processing sequence associated with redundancy switching.

  Before redundancy switching, a registration request message 801 is transmitted from the alive monitoring unit 325 to the home agent 50 via the packet distribution device 33. In the Registration Request message 801, Identification is 100, the destination IP is the IP address of the home agent 50, and the source IP address is the internal IP address xx.xx.xx.xx of the standby server 32.

  In the packet distribution device 33, registration request message information is stored as shown in the ID table 600 </ b> A of FIG. 15 by the packet distribution processing of FIG. 13, and the Registration Request message 802 is transmitted to the home agent 50.

  Here, when the redundant switching 803 occurs in the base station control device 30 and the processing shown in FIG. 14 is executed, the information is updated from the ID table 600A to the ID table 600B. That is, “3” of the communication interface 603A is updated to “2” of the communication interface 603B, and xx.xx.xx.xx of the internal address 604A is updated to aa.aa.aa.aa of the internal address 604B. The Registration Reply 804 received from the home agent 50 during redundancy switching is held in the message buffer 338 and processed after redundancy switching.

  After redundancy switching, the packet distribution device 32 performs packet distribution processing, and the transmission destination IP address of Registration Reply805 is rewritten from zz.zz.zz.zz to aa.aa.aa.aa and transmitted to the life and death monitoring unit 315 Is done. The life and death monitoring unit 315 stores the information of the monitoring data 500B from the life and death monitoring unit 325 in its own monitoring data 500A at the time of redundancy switching, so processes the Registration Reply and sets the status of the home agent 50 to “normal”. "

  According to the present embodiment, by making the standby server execute the alive monitoring, a computer used as a conventional alive monitoring apparatus becomes unnecessary. Also, by sharing the IP address assigned to the alive monitoring device with the IP address of the standby server, the number of IP addresses to be used can be reduced. In addition, since the redundant configuration of the active server and the standby server is monitored on the internal network of the base station control device, it is possible to suppress alive monitoring packets on the external network.

10: wireless terminal, 20: wireless base station, 30: base station control device, 31: active server, 32: standby server, 33: packet distribution device, 40: charging / authentication server, 50: home agent, 60: Maintenance center, 70: core network, 500: monitoring table, 600: ID table.

Claims (5)

A monitored device that executes the application, and
A first server including a first control unit in an active state and a first life-and-death monitoring unit in a standby state that monitors the life and death of the device at an application level;
A second server including a second control unit in a standby state and a second alive monitoring unit in an active state for alive monitoring the device at an application level; and
Connecting to the device via a first communication network;
The first packet connected to the first server and the second server via a second communication network, the first packet from the second alive monitoring unit of the second server toward the device, the A second source address in the second communication network is converted to a first source address in the first communication network and transmitted to the device, and a response from the device corresponding to the first packet A communication network system comprising: a control device having a packet distribution device that converts a packet transmission destination address into the second transmission source address and transmits the packet to the second server. The packet distribution device has an ID table for storing the second transmission source address in response to reception of the first packet;
Depending on whether or not the destination address of the second packet including the response packet received via the first communication network is stored in the ID table as the second source address, The communication network system according to claim 1, wherein the second packet is selectively transmitted to one of the first server and the second server. In response to the transition from the active state to the standby state of the first control unit of the first server,
The second server causes the second control unit to transition from a standby state to an active state, causes the second alive monitoring unit to transition from an active state to a standby state,
The communication network system according to claim 2, wherein the first server causes the first alive monitoring unit to transition from a standby state to an active state. The second server detects monitoring data that is a result of the life and death monitoring unit monitoring the life and death of the device at the application level in accordance with the transition of the second life and death monitoring unit from the active state to the standby state. 4. The communication network system according to claim 3, wherein the communication network system transfers to a first server. The second source address stored in the ID table is used as the second communication network of the first server in accordance with the state transition of the first alive monitoring unit and the second alive monitoring unit. 5. The communication network system according to claim 4, wherein the communication network system is updated to an address in the network.

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