JP2000069119A - Reliable communication method in network management system, communication method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the reliability of a communication route in a network management system managed by a network management protocol. SOLUTION: A plurality of agents and a data processor 3 are connected mutually communicably through transmission lines 1 and 2. The data processor 3 is an NMS managed by SNMP and is provided with a communication line state management means 321 for confirming the validity of the plural communication routes (communication route to the agent through the transmission lines 1 and 2 is decided) by sequentially issuing a test command message through the plural communication routes to the agents in each cycle set beforehand. Further, the communication line state management means 321 is provided with a storage means for storing a result to a test command in a communication line storage part 331 for each communication route and a decision means for deciding a communication line to be operated by the storage means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reliability method, method, or recording medium in a network management system.

[0002]

2. Description of the Related Art Conventionally, a general network management system (NMS: Network Management)
Normally, only one communication path is used for the System, and the UDP / IP protocol, which is a connectionless protocol, is used as the communication protocol on which the SNMP protocol is based.

A loop type network system employed as a means for ensuring reliability in the physical layer is disclosed, for example, in Japanese Patent Laid-Open No. 4-342333. The loop type network system described in this publication has an active transmission line and a standby transmission line, sets the operation transmission line to a bypass mode, and sends a test command through the standby transmission line to wait. The system transmission line is being tested.

[0004]

However, in a general network management system, only one communication path is used.
The communication between the NMS and the agent is physically disconnected and N
There is a problem that control from the MS to the agent becomes impossible. Furthermore, in the SET / GET command system of the SNMP protocol based on the UDP / IP protocol, the request ID is included in the header file, but in TRAP, the identification number itself is not defined in the message header portion. Therefore, there is a problem that it is not possible to recognize whether the message is lost between the manager and the agent.

Further, in the loop type network system, there is a problem that when the test of the standby transmission line is performed during the operation of the system, only the test of the standby transmission line is performed.

An object of the present invention has been made in view of the above problems, and has as its object to ensure the reliability of a communication route in a network management system managed by a network management protocol.

[0007]

To achieve the above object, a reliable communication system in a network management system according to the present invention comprises a transmission line, a plurality of agents, and data for managing the agents as a network management system. A reliable communication system in a network management system comprising a processing device, wherein the plurality of agents and the data processing device are managed by a network management protocol communicably connected to each other via the transmission path. A plurality of ports connected to each of the plurality of transmission lines, and a plurality of communication lines set as routes to the agent via the plurality of ports. Storage means for storing a route; It is characterized by having a channel state management means for confirming the validity of the plurality of the communication route by issuing one after the other test command message via a communication route.

Further, the communication path state management means includes recording means for recording a result of the test command for each communication route, and determination means for determining, by the storage means, a communication path to be operated by the data processing device. It is characterized by including.

A reliable communication system in a network management system according to the present invention includes a transmission line, a plurality of agents, and a data processing device that manages the agents as a network management system. In a reliable communication system in a network management system managed by a network management protocol connected to a processing device via the transmission path so as to be able to communicate with each other, the transmission path has a plurality, and the data processing apparatus A plurality of ports connected to the plurality of transmission lines one by one, a plurality of communication route areas indicating the validity of the communication route set as a route to the agent via the plurality of ports, and a current An operation status area indicating the operation status and a port indicating the designation of the port used for operation A status management table including a rear area and an agent area indicating a network address of an agent used in operation, and a test command message is sequentially issued to the agent via the plurality of communication routes at predetermined intervals. Thereby confirming the validity of the plurality of communication routes, setting a result for the test command message in the corresponding communication route area of the state management table, and setting the communication route area in which the result of the first test command is set to A communication path state management means for determining the contents of the operation state area, the contents of the port area, and the contents of the agent area by searching, and transmitting a command message to the agent by an operation of a network management program. Port area and the The data processing device and a stringent area determines the communication route to operate, is characterized by having a communication channel judging means for transmitting the command message to the agent.

[0010] A reliable communication system in a network management system according to the present invention includes a transmission path, a plurality of agents, and a data processing device for managing the agents as a network management system. In a reliable communication system in a network management system managed by a network management protocol connected to a processing device via the transmission path so as to be able to communicate with each other, the transmission path has a plurality, and the data processing apparatus A plurality of ports connected to each of the plurality of transmission paths, a plurality of management means identifiers of a plurality of management means for each network address of the plurality of agents, a message identifier of a command message at the time of transmission, and a sequence of the command message Request message to manage numbers and Management table, a plurality of communication route areas indicating the validity of the communication route set as a route to the agent via the plurality of ports, an operation state area indicating a current operation state, and the port used in operation. And a state management table including an agent area indicating a network address of an agent used in operation, and a test command message to the agent through a plurality of the communication routes at predetermined intervals. The validity of the plurality of communication routes set as routes to the agent via the plurality of ports is confirmed by sequentially issuing the results, and the result for the test command message is compared with the corresponding one of the status management tables. Set in the communication route area and the result of the test command A communication path state management means for determining the contents of the operation state area, the contents of the port area, and the contents of the agent area by searching the set communication route area; and a plurality of network management programs for the agent. Execution management means for executing and managing the management means, and when the command message is started from the execution management means to the management means, the identifier of the management means from which the command message is started and the message identifier of the command message, Is stored in the request message management table, a monitoring timer is started, and when the response message to the command message is received, the management unit identifier of the activation source is searched from the request message management table using the message identifier in the response message as a key. Message management means, and communication path determination means for determining a communication route to be operated from the port area and the agent area when sending the command message to the agent, and transmitting the command message to the agent. It is characterized by:

[0011] Further, the message management means searches the request message management table for a message identifier as a key at the time of detection of a timeout by the monitoring timer and searches for the management means identifier of the activation source. It is characterized in that the corresponding management means activates a failure process.

Further, the data processing device has a trap message management table for managing a sequence number of a trap message for each network address of the agent, and the message management means is configured to receive the trap message when the trap message is received from the agent. The sequence number in the message is compared with the previous sequence number written in the trap management table, and if it is a continuous number, the sequence number is passed to the execution management means.

Further, in the message management means,
If the sequence number is not the same as the previous sequence number, the request is sent to the agent which has received the trap message retransmission request.

A reliable communication method in a network management system according to the present invention includes a plurality of transmission paths, a plurality of agents, and a data processing device that manages the agents as a network management system. In a reliable communication method in a network management system managed by a network management protocol connected to the data processing device via the transmission path so as to be able to communicate with each other, the plurality of transmission paths are connected to the data processing device. A plurality of communication routes between the data processing device and the plurality of agents are established by connecting to a plurality of ports one by one, and the validity of the plurality of communication routes is checked at predetermined intervals. Test command message to the agent by changing the communication route Issue a test result for the test command message in a plurality of communication route areas assigned to each of the communication routes in the state management table, and operate the data processing device from the communication route area in which the test result is set. It is characterized in that a communication route to be performed is determined.

[0015] The recording medium of the present invention is a recording medium in which a program managed by a network management protocol is recorded, and a test command is transmitted to a computer by changing a communication route to an agent at predetermined intervals. A test function for testing the confirmation of the communication route by sequentially issuing messages to the agent;
A setting function of setting a test result for the test command message in a plurality of communication route areas assigned to each communication route in a state management table, and a communication route to be operated from the communication route area in which the test result is set. A program for realizing a decision function to be decided is recorded.

Further, the protocol of the network management system used in the above-mentioned reliable communication method or communication method in the network management system uses an SNMP protocol and a UDP / IP protocol which is a lower protocol of the SNMP protocol. It is characterized by having.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is directed to UDP / IP (User Data), which is generally said to be unreliable for communication.
agram Protocol Internet P
protocol based on SNMP (Simpl)
e Network Management Prot
ocol: An NMS (Network Ma) capable of ensuring communication reliability by using a mechanism such as duplexing of communication lines and retransmission control at an application level while using a simple network management protocol.
(N. System) has been proposed. Note that UDP / IP is positioned as a lower layer protocol of SNMP.

Next, an embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 2, the first embodiment of the present invention shows a system block diagram of a network management system. The network 11 includes the Internet 11 and routers 7, 8, 9,10,
Transmission lines 1, 2, 4, and 5 connected to the routers 7, 8, 9, and 10, respectively, a data processing device 3 (corresponding to a manager) connected to the transmission lines 1 and 2, and a transmission line 4 , 5 connected to an agent 6. The data processing device 3 normally manages the configuration, performance, failure, security, and the like regarding servers, transmission devices, and clients on the network, and performs NMS (NetWare Mana).
G.Gent.System). Also,
The data processing device 3 operates under program control using a processor, and performs IPna (transmission line 1 side), IPnb
Network address (transmission path 2 side), agent 6 is IPaa (transmission path 4 side), IPab (transmission path 5 side)
Side) has a network address. In addition,
A plurality of agents can be connected from the Internet 11 or the transmission paths 4 and 5, but are omitted here for the sake of explanation.

Referring to FIG. 1, there is shown a detailed block diagram of the data processing device 3 of FIG. 2. The data processing device 3 includes a port 324 connected to the transmission line 1 and a port 325 connected to the transmission line 2. , An execution management unit 31, a communication control unit 32, and a storage device 33. The communication control means 32 includes a communication path state management means 321, a communication path determination means 322, and a message management means 323. The storage device 33 includes a communication path state storage unit 331 and an identification number storage unit 332. The execution management means 31
It means general management means for managing an agent to be managed as an MS, that is, management means such as alarm management, path management, and diagnosis. However, since it is outside the scope of the present patent, a detailed description is given. Omitted. The execution management means 31 includes a plurality of management means (corresponding to management means 1 to management means n in FIG. 1) which are network management programs for performing a certain management operation on an agent using a communication path. There are more than one.

The identification number storage unit 332 includes a request message management table and a trap management table.
The request message management table contains the IP of each agent.
For each address (network address), the area of the management means identifier indicating the identifier of each management means, the area of the message identifier indicating the command message identifier at the time of transmission, and the area of the sequence number indicating the sequence number of the message at the time of transmission are obtained. Be composed. The trap management table is configured with a sequence number area indicating a trap message sequence number for each IP address in order to manage a message sequence number when a trap message is received from an agent.

The communication path state storage unit 331 has a state management table for managing the state of the communication route (communication path) between the port of the data processing device 3 and the port of the agent for each agent. For example, taking the case of the agent 6 as an example, the status management table contains IPnaIPaa (IPna) indicating the validity (usability status) of the communication route.
Indicate the communication route between na and IPaa), IPnaIP
ab (indicating the communication route between IPna and IPab), P
Each area (communication route area) of nbIPaa (indicating a communication route between IPnb and IPaa) and IPnbIPab (indicating a communication route between IPnb and IPab) and the current operation state (operating, non-operating, or in failure) ) And an N_A indicating each port number (324 or 325) of the data processing device 3 used in the operation.
A_A indicating the area (port area) of the ctSystem and the address of the port of the agent 6 used in the operation
ActSystem (agent 6 side) area (agent area).

The message management means 323 associates an identifier of the requesting management means with the identifier of the requesting management means at the time of the command message transmission request from the execution management means 31, and stores the identifier in the request message management table of the identification number storage unit 332. Together with the communication path determination means 32
2 to the communication path together with the message identifier. On the agent 6 side, the identifier is directly added to the response to the command message, and a response message is returned. Therefore, in this reception processing, the call execution management unit 31 is called based on the information read from the request message management table of the identification number storage unit 332.
Distribute to In this way, it is managed for each agent.

Further, in the trap receiving process from the agent 6, a sequence of sequentially counting up on the agent 6 side is stored in the identification number storage unit 332 for the purpose of identifying the message. The continuity check of the message identification number is performed by comparing with the number.

Further, when this message is discontinuous, the agent 6 is transmitted via the communication path determining means and the selected transmission path 1 or 2 without the intervention of the execution managing means 31.
To resend the message.

Next, the operation of the first embodiment of the present invention will be described in detail with reference to FIGS.

Referring to FIG. 2, the dynamic routing function of routers 7, 8, 9, and 10 at the boundary to the Internet 11 allows communication from IPna to IPaa and IPab, and communication from IPnb to IPaa and IPab. Is possible, and conversely, Ipaa to IPna, IPn
b, and communication from IPab to IPna and IPnb is also possible. As described above, the system physically adopts the duplex configuration (preparing two ports) of the communication path. Under this configuration, specific communication routes, that is, IPna to router 7 (transmission path 1), IPnb to router 8 (transmission path 2), Ipaa to router 9 (transmission path 21), IPab to
Even if a physical failure occurs in one of the routers 10 (transmission path 22) and communication becomes impossible, an alternative communication route is selected to provide a mechanism for continuing communication.
The operation of each means based on this environment will be described below.

FIG. 3 shows a procedure executed by the communication path state management means 321. Communication path state management means 3
Reference numeral 21 denotes two communication paths in FIG. 2, that is, from IPna to IPaa and IPab in a predetermined cycle.
And the communication path from IPnb to IPaa, IPa
The validity with the communication path toward b is checked in order, and the result (usable or unusable) is stored in the state management table of the communication path state storage unit 331. That is, a ping command is issued from IPna to IPaa, and the result is
stored in the naIPaa area (steps S1 and S1).
2). Next, a ping command is issued from IPna to IPab, and the result is stored in the IPnaIPab area (steps S3 and S4). Next, from IPnb to IPa
issue a ping command to a.
It is stored in the Paa area (steps S5 and S6). Next, a ping command is issued from IPnb to IPab, and the result is stored in the IPnbIPab area (steps S7 and S8). By the way, the management state of the communication path when using the path to be operated from the state state of the communication path includes the state shown in FIG.
As shown by 0, there are 32 possible cases for the agent 6, one of which exists as the state of the communication path for the agent 6. The communication route of the new effective system (the communication route to be operated) is determined by the logic shown in FIG.
This result is stored in the N_ActSystem area and the A_Act
Store in the ActSystem area (step S
9, S10). The communication route may be determined, for example, by assigning a priority to each port and determining the communication route from the state of each communication path.

The ping command is an IP in the Internet world between two terminals via a network.
There is a test command to check whether the connection is correct at the layer level. As a protocol, ICMP (Internet Control Meme) corresponding to an application layer of a TCP / IP layered model is used.
This protocol is based on the protocol (sshort protocol) and refers to a mechanism for conducting a continuity test by communicating between a client-side (or NMS) program and a server-side (or agent) program.

FIGS. 4 to 7 show the message management means 323.
4 shows four procedures executed in the first embodiment.

The message management means 323 performs processing in response to a command transmission request from the higher-level execution management means 31, an SNMP command response request from the lower-level communication path determination means 322, or an SNMP trap reception request from the agent 6. . At this time, the identification number storage unit 33
The sequence number (message order) is checked based on the message identifier stored in the request message management table of No. 2 and the command request is associated with the response, and the response does not return within a fixed time. Report the timeout event of the upper execution management means 3
Perform for 1 Further, the sequence number at the time of trap reception is compared with the sequence number stored in the trap management table of the identification number storage unit 332, and when a discontinuity occurs, the execution management unit 31 is notified to the agent 6.
It has the function of making a retransmission request without the intervention of Hereinafter, description will be made in correspondence with the drawings.

FIG. 4 shows that the execution management means 31
GET, SET command request of message management means 3
23 shows an execution procedure at the time of reception. That is,
When the response to the command request is returned from the agent 6, the identifier of the management unit of the activation source is stored in the request message management table of the identification number storage unit 332 in order to correctly return the response to the execution management unit 31 of the request source. (Step S41). Next, the message identifier set in the header of the SNMP message is updated and set in the corresponding message, and is simultaneously stored in the request message management table of the identification number storage unit 332 (step S42). Based on this message, a message transmission request is issued to the communication path determination means 322, and a monitoring timer for monitoring the response to this message is started (steps S43, S44). This monitoring timer activates the processing of FIG. 6 when a predetermined time elapses.

FIG. 5 shows the message management means 3 when a command response is returned via the communication path determination means 322.
23 shows the procedure of FIG. That is, a message identifier is extracted from the header portion of the received SNMP command response message, and the request message management table in the identification number storage unit 332 is searched to find the corresponding start source management means (step S51). If no corresponding activation source management means is found, this message is discarded. If found, the monitoring timer corresponding to this message is stopped, and the corresponding management means is activated (steps S52 to S54).

FIG. 6 shows the processing of the message management means 323 which has reached the upper limit time (timeout) of the monitoring timer started in FIG. 4 and is started from the timer. In other words, a search is made for the management means of the corresponding boot source from the identifier of the management means (step S61). If no corresponding activation source management means is found, this message is discarded. If found, an error event corresponding to this message is transmitted to the management means of the activation source (steps S62 and S63).

FIG. 7 shows that the trap message issued by the agent 6 is transmitted to the communication path and the communication path determining means 32.
2 shows the processing of the message management means 323 when the report is made via the second message. That is, a trap identifier and a sequence number included in the message are extracted (step S71). This sequence number and identification number storage unit 3
The sequence number is compared with the sequence number of the previous trap included in the trap management table of No. 32 to determine whether the sequence number is continuous (that is, whether the current sequence number is equal to the previous sequence number included in the identification number storage unit 332 + 1). It is confirmed whether or not it is (steps S72, S73). If the conditions do not match, it is considered that a trap has been lost in the communication path, and a request for retransmission of this trap is sent to the communication path determination means 32.
2 (step S74). In the case of the condition match, it is considered that the trap is not missed, and therefore, the trap is normally transmitted to the predetermined higher-level management means as it is (step S75). The sequence number of this trap is stored in the identification number storage section 332 (step S76).

FIGS. 8 and 9 show the processing in the communication path determining means 322. FIG.

In general, it is determined to which of two communication paths (two ports) a request from the message management means 323 is to be transmitted, based on information stored in the communication path state storage unit 331. The command request is transmitted only to the communication path. Command request sent from agent 6,
As for the trap message, only the message that comes from the above-mentioned effective and operating communication path is made valid, and the message that comes from the other is discarded. The specific procedure is described below.

FIG. 8 shows a procedure when the communication path determination means 322 receives a command message transmission request from the message management means 323. That is, the communication path state storage unit 33
N_ActSystem stored in the state management table of No. 1
The em (new effective system) is read (step S81). This value is determined (step S82). If the result is 1, it is determined to be the address IPna, and the message is transmitted from the port 324 to the address corresponding to A_ActSystem stored in the state management table of the communication path state storage unit 331 (step S83). The result is 2
If so, it is determined that the address is IPnb, and the message is transmitted from the port 325 to the address corresponding to A_ActSystem stored in the state management table of the communication path state storage unit 331 (step S8).
4).

FIG. 9 shows processing when a command response or a trap signal is received from the transmission path 1 (port 324) or the transmission path 2 (port 325). That is, N_Act is stored in the state management table of the communication path state storage unit 331.
The system is read (step S91). It is checked whether the port receiving the message is the same as the number of the system indicated by N_ActSystem (step S9).
2). If they are the same (that is, if it is determined that a message has been received from the valid system), this message is transmitted to a higher-level message management unit (step S93). If not, discard this message.

Next, a second embodiment of the present invention will be described with reference to the drawings. Referring to FIG. 11, a second embodiment of the present invention shows a system block diagram of a network management system, in which the Internet 11
Routers 7, 8, at the connection boundary to the Internet 11,
9, 10; transmission paths 1, 2, 4, 5 connected to the routers 7, 8, 9, 10 respectively; and a data processing device 21 (manager) which is a computer connected to the transmission paths 1, 2. ), And an agent 6 connected to the transmission paths 4 and 5. That is, only the data processing device 3 in FIG. 2 of the first embodiment is different, and the other configuration is the same.

Referring to FIG. 11, the data processing device 21
Is configured to read from the recording medium 22 storing the communication path management program into a storage unit (not shown). The port 324 connected to the transmission path 1, the port 325 connected to the transmission path 2, It comprises means 31, communication control means 32, and storage device 33. The communication control means 32 includes a communication path state management means 321, a communication path determination means 322, and a message management means 323. The storage device 33 includes a communication path state storage unit 331 and an identification number storage unit 332. The communication path state management program is read from the recording medium 22 and is stored in the data processing device 2.
Part 1 of the operation is controlled. At this time, the data processing device 21 that has read the communication path management program performs the same processing as the data processing device 3 described in the first embodiment.
That is, the communication path state means 321 of the data processing layer 21 in FIG. 12 shows a function when the data processing apparatus 21 executes a communication path management program stored in a storage unit (not shown). Communication state management means 32
The same processing as in step 1 is executed.

The operation in the second embodiment will be described with reference to FIGS.
The data processing device 3 of the embodiment is replaced with the data processing device 2
Since the same operation as that of the first embodiment is performed only by replacing with 1, the description is omitted below.

As described above, in the communication route test, the route of the communication route can be determined at the IP layer level. Therefore, even during system operation (during user use), the communication route can be determined without shutting down the system. Can test. Further, since a state management table for communication routes is provided, the state of each communication route can be always grasped.

Further, when the trap message from the agent is received, the sequence number of the trap message is managed, so that the data processing device can reliably receive the data without data loss.

[0045]

The first effect is that in communication of a layer below the UDP / IP layer, high reliability in communication can be guaranteed without changing the message format and specifications of the existing protocol. The reason is that disconnection of the communication path at the physical level can be avoided by cooperation of the communication path determination means, the communication path state management means, and the communication path state storage unit.

The second effect is that by implementing the retransmission mechanism within the framework of the protocol of the SNMP layer, it is possible to guarantee the wide reliability of the command response from the agent and the trap transmission. The reason is that a mechanism has been implemented that allows the message management means to determine whether a message has been lost by checking the current value of the message identifier. In addition, when a loss actually occurs, the upper layer is notified of this, or in the case of a trap, a retransmission request is issued autonomously without the intervention of the execution management means, and the agent can retransmit the trap.

[Brief description of the drawings]

FIG. 1 is a detailed block diagram illustrating a configuration of a data processing device in FIG. 2;

FIG. 2 is a system block diagram showing a system configuration of a network management system according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing an operation of a communication path state management unit of FIG. 1;

FIG. 4 is a flowchart showing an operation of a command message request process in the message management means of FIG. 1;

FIG. 5 is a flowchart showing an operation of a command message response process in the message management means of FIG. 1;

FIG. 6 is a flowchart showing the operation of a command message transmission timeout process in the message management means of FIG. 1;

FIG. 7 is a flowchart showing an operation of a trap message receiving process in the message management means of FIG. 1;

FIG. 8 is a flowchart showing an operation of a command message transmission process in a communication path determination unit.

FIG. 9 is a flowchart showing an operation when a command response message or a trap signal is received in the communication path determining means.

FIG. 10 is a diagram illustrating a possible 3 in the communication path state storage unit (state management table) of FIG. 1 with reference to the agent 6 of FIG.
It is a table | surface which shows the combination of two kinds of state modes.

FIG. 11 is a system block diagram showing a system configuration of a network management system according to a second embodiment of the present invention.

FIG. 12 is a detailed block diagram illustrating a configuration of the data processing device of FIG. 11;

[Explanation of symbols]

 1, 2, 4, 5 Transmission path 3, 21 Data processing device 22 Recording medium 6 Agent 7, 8, 9, 10 Router 11 Internet 31 Execution management means 32 Communication control means 33 Storage device 321 Communication path state management means 322 Communication path Determination means 323 Message management means 324, 325 Port 331 Communication path state storage section 332 Identification number storage section

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04L 12/56

Claims (11)

[Claims] 1. A communication system comprising: a transmission line, a plurality of agents, and a data processing device that manages the agent as a network management system, wherein the plurality of agents and the data processing device communicate with each other via the transmission line. In the reliable communication system in the network management system connected as possible, the transmission path has a plurality, and the data processing device includes a plurality of ports connected to the plurality of transmission paths one by one; Storage means for storing a plurality of communication routes set as routes to the agent via the port; and a test command message is sequentially sent to the agent via the plurality of communication routes at predetermined intervals. Communication path state management means for confirming the validity of a plurality of said communication routes by issuing them individually. Characteristic reliable communication method in network management system. 2. The communication path state management means includes: recording means for recording a result of the test command for each communication route; and determination means for determining, by the storage means, a communication path to be operated by the data processing device. The reliable communication system in the network management system according to claim 1, wherein the communication method includes: 3. A transmission line, a plurality of agents, and a data processing device that manages the agent as a network management system, wherein the plurality of agents and the data processing device communicate with each other via the transmission line. In the reliable communication system in the network management system connected as possible, the transmission path has a plurality, and the data processing device includes a plurality of ports connected to the plurality of transmission paths one by one; A plurality of communication route areas indicating the validity of the communication route set as a route to the agent via the port, an operation state area indicating a current operation state, and a port area indicating designation of the port used in operation Status management table that contains the agent area that indicates the network address of the agent used in operation And by sequentially issuing test command messages to the agent via the plurality of communication routes at predetermined intervals, thereby confirming the validity of the plurality of communication routes. A result is set in the corresponding communication route area of the state management table, and the contents of the operation state area, the contents of the port area, and the agent are searched by searching the communication route area in which the result of the test command is set. Communication path state management means for determining the contents of the area; and determining a communication route operated by the data processing apparatus from the port area and the agent area when sending a command message to the agent by the operation of a network management program. And sends the command message to the Reliable communication method in a network management system characterized by having a communication channel judging means for transmitting to the Ento. 4. A transmission line, a plurality of agents, and a data processing device for managing the agent as a network management system, wherein the plurality of agents and the data processing device communicate with each other via the transmission line. In the reliable communication method in the network management system that is connected as possible, the transmission path includes a plurality, and the data processing device includes a plurality of ports connected to the plurality of transmission paths one by one; A request message management table for managing the management means identifiers of the plurality of management means, the message identifier of the command message at the time of transmission, and the sequence number of the command message for each network address of the agent, and via the plurality of ports Validation of the communication route set as a route to the agent Status management table including a plurality of communication route areas indicating the characteristics, an operation state area indicating the current operation state, a port area indicating the port used for operation, and an agent area indicating the network address of the agent used for operation. And a plurality of ports set as routes to the agent via the plurality of ports by sequentially issuing test command messages to the agent via the plurality of communication routes at predetermined intervals. By confirming the validity of the communication route, setting a result for the test command message in the corresponding communication route area of the state management table, and searching the communication route area in which the result of the test command is set. The contents of the operation status area and the contents of the port area Communication path state management means for determining the contents of the agent area; execution management means for executing and managing a plurality of management means as a network management program for the agent; and execution management means for the management means from the execution management means. At the time of starting the command message, the identifier of the management unit from which the command message was started and the message identifier of the command message are stored in the request message management table, a monitoring timer is started, and the response message is received when the response message to the command message is received. A message management means for searching the request message management table for the management means identifier of the activation source using the message identifier in the response message as a key; and a port area for transmitting the command message to the agent. Determining a communication route to operate from an agent area, reliable communication method in a network management system characterized by having a communication channel judging means for transmitting the command message to the agent. 5. The method according to claim 1, wherein the message management means searches the request message management table for a message identifier as a key when the monitoring timer detects a timeout and detects the management means identifier of an activation source. 5. The reliable communication system in a network management system according to claim 4, wherein a failure process is started by a corresponding management unit. 6. The data processing apparatus has a trap message management table for managing a trap message sequence number for each network address of the agent, and the message management means is configured to execute the trap message when a trap message is received from the agent. Compare the sequence number in the message with the previous sequence number written in the trap management table,
5. The reliable communication method in a network management system according to claim 4, wherein a serial number is passed to said execution management means. 7. The trust in the network management system according to claim 6, wherein the message management means performs the trap message retransmission request to the agent that has received the retransmission request unless the sequence number is the same as the previous sequence number. Communication system. 8. A communication system comprising: a plurality of transmission paths; a plurality of agents; and a data processing device that manages the agents as a network management system, wherein the plurality of agents and the data processing devices are interconnected via the transmission lines. A reliable communication method in a network management system communicably connected to the data processing device and the plurality of ports by connecting the plurality of transmission paths to a plurality of ports of the data processing device one by one. Establish a plurality of communication routes with the agent, and, at predetermined intervals, change the communication route to issue a test command message to the agent in order to confirm the validity of the plurality of communication routes, and cause the agent to issue the test command message sequentially. The test command is stored in a plurality of communication route areas assigned to each of the communication routes in the state management table. A reliable communication method in a network management system, comprising: setting a test result for a message, and determining a communication route operated by the data processing device from the communication route area in which the test result is set. 9. A recording medium on which a program managed by a network management system is recorded, wherein a test command message is sequentially sent to the agent by changing a communication route to the agent at predetermined intervals. And a setting function for setting a test result for the test command message in a plurality of communication route areas assigned to each communication route in a state management table by issuing a test function for confirming the confirmation of the communication route. And a determining function of determining a communication route to be operated from the communication route area in which the test result is set. 10. The network management system according to claim 1, wherein the protocol uses an SNMP protocol and a UDP / IP protocol which is a lower protocol of the SNMP protocol.
A reliable communication method in the network management system described in the above. 11. The reliability in the network management system according to claim 8, wherein a protocol of the network management system uses an SNMP protocol and a UDP / IP protocol which is a lower protocol of the SNMP protocol. Communication method.