JP5930383B2 - Network system, frame transmission method, network device, priority setting program - Google Patents

Description

  The present invention relates to a network system, a frame transmission method, a network device, and a priority setting program, and particularly relates to transmission of a trap frame for reporting an alarm or an event.

  In the operation of network devices, an alarm notification communication path for reporting to a network management device (NMS: Network Management System) when a setting, alarm, or event occurs in the device separately from the main signal network. May be prepared. Alarm and event reporting is realized by a trap function of SNMP (Network Monitoring Protocol) (for example, Patent Document 1).

  4 and 5 show an overview of alarm and event notification by the SNMP (Simple Network Management Protocol) trap function. As shown in FIG. 4, network devices (NE) 101a, 101b, and 101c are connected to a network management device (NMS) 102 via alarm communication channels different from the main signal network. Here, for example, when a failure occurs in the network device (NE) 101c, as shown in FIGS. 4 and 5, the SNMP agent of the network device (NE) 101c sends an alarm notification with a UDP (User Datagram Protocol) packet. A trap frame for notifying the network management device (NMS) 102 of the occurrence of a failure is transmitted via the communication channel for use. This trap frame is received by the SNMP manager of the network management device (NMS) 102.

  Also, an inform method has been proposed in SNMP version 3 to ensure that the trap frame reaches the SNMP manager. In the inform method, the SNMP manager that has received the trap frame and detected the failure returns a response to the SNMP agent in response to the notification of the trap frame. If there is no response, the SNMP agent again detects the failure. This is a notification method.

In addition, the technique relevant to this invention is disclosed by patent documents 1-3.
Patent Document 1 discloses a technology of a failure recovery apparatus that can attempt recovery of a failure even when a failure other than the failure described in the failure handling rule occurs.
Patent Document 2 discloses a technique for preventing a serious failure in advance by knowing the connection state of each route to be inspected, particularly a plurality of routes connecting between a server and a client terminal, grasping the operating state of the system. ing.
Patent Document 3 discloses a technology for suppressing an increase in the load on each device constituting a network system resulting from concentrated transmission of event notification messages such as a large number of trap frames from a network device in a short period of time. ing.

JP 2005-346331 A JP 2006-148376 A JP 2010-245577 A

  Here, there may be no alarm notification communication path in the network system disclosed in the above-described technology. In such a network system, when an alarm such as a failure occurs is notified from the network device (NE) to the network management device (NMS), if congestion occurs, the trap frame does not reach the network management device (NMS). The alarm occurrence report to the user may be delayed. For example, in a case where the allocated communication band is narrow and limited, such as a wireless network system, a network device (for example, network device (NE101b)) whose network topology is close to the network management device (NMS). Assume that a trap frame is transmitted from another distant network device (for example, the network device (NE101c)) while communication for setting processing or the like is performed. In this case, the communication path may be congested due to the setting process, and a trap frame from a distant network device (for example, the network device (NE101c) does not reach the network management device (NMS) 102, so that an alarm is reported to the user. May be delayed.

  Here, in the inform system described above, the SNMP manager can reliably transfer the trap frame by returning a response to the SNMP agent in response to the notification of the occurrence of the failure from the SNMP agent. However, as shown in FIG. 6, in the inform system, for example, the trap frame from the network device (NE) 101c does not reach the network management device (NMS), and the network management device (NMS) is connected to the network device (NE). Even if the retransmission of the trap frame is requested to 101c, if the congestion occurs, the retransmission request cannot be delivered to the network device (NE) 101c. Therefore, the trap frame delay due to the occurrence of congestion on the communication path cannot be eliminated even with the inform method.

  Therefore, an object of the present invention is to provide a network system, a frame transmission method, a network device, and a priority setting program that can solve the above-described problems.

In order to solve the above-described problem, a network system according to the present invention is a network system including a network device and a network management device, and the network device transmits the frame to the network management device. determines the type of frame to be transmitted, the have a priority setting unit that sets a priority in accordance with the type of discrimination frame, the priority setting section, the difference in the priority range network device can send The priority is calculated by performing weighting according to the frame type .

A frame transmission method according to the present invention is a frame transmission method for a network system including a network device and a network management device, and the type of frame to be transmitted when the frame is transmitted from the network device to the network management device. The priority is calculated by assigning a weight according to the determined frame type to the difference in priority within the range that can be transmitted by the network device , and the priority is set.

The network device according to the present invention is a network device that transmits a frame to a network management device, and determines the type of the frame to be transmitted when transmitting the frame to the network management device, and the determined type of the frame A priority setting unit that sets the priority according to the priority, and the priority setting unit calculates the priority by weighting the difference in priority within a range that can be transmitted by the network device according to the frame type. Features.

The priority setting program according to the present invention determines the type of frame to be transmitted when transmitting a frame to the network management device to a computer of the network device that transmits the frame to the network management device. Function as a priority setting means for setting the priority according to the type of the network, and the priority setting means weights the difference in the priority of the range that can be transmitted by the network device according to the frame type to set the priority. calculate.

  According to the present invention, the reachability of a trap frame from a network device having an SNMP agent to a network management device having an SNMP manager can be improved.

It is a block diagram which shows the structure of the network system which concerns on embodiment of this invention. It is a flowchart which shows the process in a priority setting part. It is explanatory drawing of the basic composition of this invention. It is explanatory drawing of the outline | summary of the notification of the alarm by the trap function of SNMP, and an event. It is explanatory drawing of the outline | summary of the notification of the alarm by the trap function of SNMP, and an event. It is explanatory drawing of an inform function.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a network system according to an embodiment of the present invention. As shown in FIG. 1, a network device (NE) 1 is connected to a network management device (NMS) 2 by a communication network 3.

  The network management device (NMS) 2 includes hardware and software for managing a network. The network management device (NMS) 2 is provided with an SNMP manager 51.

  As shown in FIG. 1, a network device (NE) 1 according to the present embodiment includes an alarm monitoring unit 11, an SNMP agent (trap frame generating means) 12, a priority setting unit 13, and an L2 switch unit 14. I have.

  The alarm monitoring unit 11 monitors an internal state of the apparatus and an alarm (abnormality occurrence) of the hardware 15. When an abnormality occurs, the alarm monitoring unit 11 requests the management unit that manages the hardware 15 constituting the apparatus to transmit an alarm and transmits an alarm notification request to the SNMP agent 12.

  The SNMP agent 12 receives an alarm notification request from the alarm monitoring unit 11 when an alarm occurs in the network device (NE) 1, and generates an alarm to the SNMP manager 51 of the network management device (NMS) 2. A trap frame for notifying is sent. In addition, the SNMP agent 12 responds to a setting / acquisition request from the SNMP manager 51 of the network management device (NMS) 2 or a function for performing necessary information and setting in the device or the network management device (NMS) 2. The SNMP manager 51 has a function of returning a response for transmitting information corresponding to the acquisition request.

  The priority setting unit 13 determines the type of frame to be transmitted, and sets (records) priority information in the frame for each type. The L2 switch unit 14 is a device that transmits and receives various signals in the OSI layer 2 hierarchy.

Next, the operation of the above embodiment will be described.
First, when the alarm monitoring unit 11 detects a failure of the hardware 15, the alarm monitoring unit 11 requests the SNMP agent 12 to notify the alarm. When receiving an alarm notification from the alarm monitoring unit 11, the SNMP agent 12 generates a trap frame to the SNMP manager 51 of the network management device (NMS) 2.

  Normally, the trap frame from the SNMP agent 12 is sent from the L2 switch unit 14 directly to the SNMP manager 51 of the network management device (NMS) 2. On the other hand, in this embodiment, a priority setting unit 13 is provided, and the SNMP agent 12 sends a trap frame to the priority setting unit 13.

Next, the priority setting unit 13 determines the type of frame to be transmitted. The priority setting unit 13 sets priority information corresponding to the frame type in the frame. At this time, the priority setting unit 13 sets CoS _max that is a preset upper limit value of CoS (Class of service), CoS _min that is a lower limit value CoS, and the type of frame to be transmitted. , The priority is calculated and set in the frame by an algorithm as shown in the equation (1), and the frame is transmitted to the L2 switch unit 14.

  Here, the priority weighting coefficient α is set as shown in the following table.

  FIG. 2 is a flowchart showing processing in the priority setting unit 13. As shown in FIG. 2, when the priority setting unit 13 receives a frame transmission request (step S1), the priority setting unit 13 determines the type of frame (step S2), and according to the type of frame, the algorithm of equation (1) Thus, the priority is calculated (step S3). Then, a frame for which priority is set is transmitted (step S4).

  The priority of the trap frame calculated by the algorithm of the expression (1) and sent to the SNMP manager 51 of the network management device (NMS) 2 when an alarm is generated is higher than that of a normal frame. The priority setting unit 13 uses other algorithms (calculation formulas) to increase the priority of the trap frame sent to the SNMP manager 51 of the network management device (NMS) 2 when an alarm occurs than the priority set for the frame during normal operation. You may calculate as follows.

  The frame whose priority is set by the priority setting unit 13 is sent to the L2 switch unit 14. The L2 switch unit 14 sends the frame out of the apparatus according to the transfer database held by itself. A device existing on a communication network between the network device (NE) 1 and the network management device (NMS) 2 transfers a trap frame transmitted from the network device (NE) 1 to the network management device (NMS) 2. In this case, QoS processing is performed according to the priority, and the trap frame is transferred to the network management device (NMS) 2. Thereby, the SNMP manager 51 of the network management device (NMS) 2 acquires the trap frame, and performs processing based on the alarm detected by the trap frame.

  As described above, in the present embodiment, the priority setting unit 13 is provided in the network device (NE) 1, and the priority is set for the trap frame generated by the SNMP agent 12. As a method for setting the communication priority, instead of the method for setting the CoS value set in the Ethernet (registered trademark) frame as described above, the DSCP (Differentiated Services) of the IP (Internet Protocol) frame is used. Code Point (RFC2474) may be set by a method of setting.

  CoS sets priority by 3 bits in a 4-byte VLAN header of an Ethernet (registered trademark) frame. On the other hand, DSCP sets the priority using the first 6 bits of the 8 bits of the TOS (Table Of Service) field in the IP header. Note that the priority setting is not limited to DSCP or CoS.

  Thus, in the present embodiment, the priority setting unit 13 can set a higher priority for the trap frame than other communication frames. As a result, the trap frame from the network device (NE) 1 can be preferentially transmitted to the network management device (NMS) 2 and the trap frame can be reliably transmitted without delay even when the communication path is congested. Can be transferred to.

  If a high priority is assigned to all trap frames, there is a possibility that congestion due to trap frames may occur when trap frames occur frequently. Therefore, in this embodiment, the priority is determined by an algorithm as shown in Expression (1).

  The algorithm shown in Expression (1) is a frame (trap frame) that should reach the network management device (NMS) 2 with respect to the CoS value within the range that can be transmitted by the device set in advance in the network device (NE) 1. ) Is an algorithm for calculating the priority so that a high priority is assigned. Furthermore, priority is assigned to the alarm notification in the trap frame according to the stages of “Critical”, “Major”, “Minor”, and “Normal”.

  In equation (1), the priority setting algorithm has been described for the CoS value of the Ethernet (registered trademark) frame, but the same applies to the DSCP value of the IP frame.

  In the embodiment of the present invention, the reachability of the trap frame to the network management device (NMS) 2 can be ensured by setting the priority of the frame reaching the network management device (NMS) 2 high. Further, the reachability of the frame to the network management device (NMS) 2 can be changed for each type by changing the priority coefficient and the settable priority range.

  In the embodiment of the present invention, since an existing frame format can be used, there is no influence on an existing apparatus or a communication network, and there is no influence on an interconnection with an existing apparatus. .

  In the embodiment of the present invention, since the priority can be set by a simple installation value and calculation, the reachability of the trap frame can be improved without imposing a large load on the network device (NE).

  In the above example, reachability is ensured by assigning a high priority to notifications and settings that should be prioritized, but the transmission priority that does not require real-time property is the transmission that requires real-time property. The reachability may be ensured by setting the priority to a lower priority.

  As described above, the basic configuration of the frame transmission method according to the present invention is a network system including the network device (NE) 1 and the network management device (NMS) 2 as shown in FIG. ) 1 includes a priority setting unit 13 that determines the type of frame to be transmitted when transmitting a frame to the network management device (NMS) 2 and sets the priority according to the determined type of frame. It is characterized by this. Thereby, the priority of the frame reaching the network management device can be set high, and the reachability of the trap frame can be ensured.

  Each of the above devices has a computer system inside. Each process described above is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing the program. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

1: Network equipment (NE)
2: Network management device (NMS)
11: Alarm monitoring unit 12: SNMP agent 13: Priority setting unit 14: L2 switch unit 51: SNMP manager

Claims (8)

A network system comprising a network device and a network management device,
The network device is:
When transmitting a frame to the network management device determines the type of frame that the transmission, have a priority setting unit that sets a priority according to the type of frame the determination,
The priority setting unit calculates a priority by weighting a difference in priority within a range that can be transmitted by a network device according to a frame type . Network system according to claim 1 wherein the priority setting section, characterized in that to set a higher priority relative to the frame. The priority setting unit, the network system according to claim 1 or 2, characterized in that to set a priority to Cos (Class of service) value in the frame. The priority setting unit, the network system according to claim 1 or 2, characterized in that the priority is set by the DSCP (Differentiated Services Code Point) value in the frame. A network system frame transmission method comprising a network device and a network management device,
When transmitting a frame from the network device to the network management device, the type of the frame to be transmitted is determined, and the difference in priority within the range that can be transmitted by the network device is weighted according to the determined type of frame. Calculating a priority and setting the priority. A network device that transmits a frame to a network management device,
When transmitting a frame to the network management device, a priority setting unit that determines the type of the frame to be transmitted and sets a priority according to the determined type of the frame ,
The network device according to claim 1, wherein the priority setting unit calculates the priority by weighting a difference in priority within a range that can be transmitted by the network device according to a frame type . Furthermore, it has a trap frame generation means for transmitting the frame to the network management device when an alarm occurs,
The priority setting unit, the network device according to claim 6, characterized in that to set a higher priority relative to the frame. To the network device computer that sends the frame to the network management device,
When transmitting a frame to the network management device, determine the type of the frame to be transmitted, and function as a priority setting means for setting the priority according to the determined type of frame,
The priority setting means is a priority setting program for calculating a priority by weighting a priority difference in a range that can be transmitted by a network device according to a frame type .

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