WO2015133888A1

WO2015133888A1 - A system and method for polling changes in a network device using snmp

Info

Publication number: WO2015133888A1
Application number: PCT/MY2015/000013
Authority: WO
Inventors: Chin Wee WONG
Original assignee: Mimos Berhad
Priority date: 2014-03-05
Filing date: 2015-02-27
Publication date: 2015-09-11
Also published as: MY177528A

Abstract

The present invention relates to a system and method for polling changes in a network device (10) in a periodically manner by using a simple network management protocols (SNMP) agent (13). Specifically, the system and method allow a management system (20) to update a network (30) with any changes that occurred in the network device (10) and at the same disregard any unchanged information. Therefore, the system and method promote efficiency; prevent overloading the network (30) with unnecessary unchanged information, and ease network traffic.

Description

A SYSTEM AND METHOD FOR POLLING CHANGES IN A NETWORK

DEVICE USING SNMP

TECHNICAL FIELD OF THE INVENTION

This invention relates to a system and method for polling changes in a network device, and more particularly to a system and method for polling changes in a network device using simple network management protocols (SNMP).

BACKGROUND OF THE INVENTION

Element management system (EMS) and network management system (NMS) are implemented generally to monitor and administer a computer network or network devices and configuring the devices, usually via simple network management protocols (SNMP). The EMS and NMS also collect information from managed devices and store the information in a database for users to view both online and offline. In order to ensure the information in the EMS or NMS database is updated, the EMS or NMS needs to use a suitable management protocol that will allow the information be collected and polled periodically. However, in most cases, this has generated a large amount of traffic in the network, which is due to periodic updates even though there is no change in the collected data.

Some of the prior arts have introduced management system to poll or detect changes in network devices. For example, in patent US 6,122,639 disclosed mechanism for network device information collection and change detection while international patent publication no. WO 2004/104739 A2 disclosed a method of accessing data sources and obtaining transaction information relating to changes in the data sources. Both patent US 6,122,639 and WO 2004/104739 A2 describe the information and the changes in metadata, but these methods are considered as subjective, lacking in interoperability, and unable to provide comprehensive descriptions. Thus, the methods may need to be improved further. In another example, patent EP 0621706 B1 disclosed a system and a method allowing SNMP to gather updates by using indexing system while patent US 6,539,540 B1 disclosed a method for optimising detection of a change in MIB information encoded as byte arrays. In patent US 7,991 , 865 B2, the result returned is in aggregate change identifiers (ACI). The aforementioned prior arts EP 0621706 B1 , US 6,539,540 B1 , and US 7,991 , 865 B2 demonstrated different method to detect and collect information from a managed device. From the disclosure of the prior arts, there is a need to have a method for SNMP to poll only the changes occurring in MIB object instance of a MIB group and the data can be accessed periodically without causing heavy traffic and burden to the network.

In addition, the method must be interoperable and easy to be managed as the change updates and polling will be regular in the network. It is favourable to have a method and system that is able to reduce average lookup costs as well. Therefore, the system and method of polling changes from the managed devices need to be improved and optimized to avoid the generation of unnecessary large amounts of traffic in the network.

Accordingly, it can be seen in the prior art that there exists a need to provide a system and method for polling changes in a network device using SNMP agents without causing heavy traffic to the network.

SUMMARY OF THE INVENTION

The present invention is generally related to a system and method for polling changes in a network device using simple network management protocols (SNMP).

The method allows the management system to periodically update the network with the changes occurring in the network device. The updates include polling changes in management information base (MIB) object instance and disregarding information that has not changed during change detection to prevent network overload. It is another objective of the present invention to provide a management system for a network device to poll changes in management information base (MIB) object instance in MIB group while reducing traffic in the network.

Accordingly, this may be achieved in accordance with an embodiment of the present invention, where the method for polling changes in a network device using a SNMP agent, characterized by the steps of: receiving an information request from a management system to start polling in the network device, said information request comprising a first identifier to identify the management system that sends the information request and a second identifier to identify a MIB object instance within a MIB group; informing the management system that the polling has started; collecting current MIB value of the MIB object instance identified via the second identifier and comparing said current MIB value against a previous MIB value; generating a hash table comprising the current MIB value of the MIB object instance that has changed, and the second identifier that corresponds to said MIB object identifier; storing the current MIB value of all the MIB object instances identified via the second identifier for future polling; and informing the management system that the polling is completed.

Further in accordance with a preferred embodiment of the present invention, the management system queries the hash table to obtain the changes in the network device.

There is also provided in accordance with a preferred embodiment of the present invention a system for polling changes in a network device using the preferred method in the present invention, the system comprising a management system and a network device, characterised by: the network device further comprises: a first storage for storing current MIB value of the requested MIB object instance in a MIB group; a second storage for storing hash table, wherein the hash table comprises the current MIB value of the MIB object instance that has changed, and a second identifier that corresponds to MIB object identifier; a SNMP agent for receiving information request and detecting change; and wherein the network device and the management system are connected via a network.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention will be more readily understood and appreciated from the following detailed description when read in conjunction with the accompanying drawings of the preferred embodiment of the present invention, in which:

Figure 1 is a diagram showing a system for polling changes in a network device using SNMP agent;

Figure 2 shows a general hierarchy of a MIB structure; and

Figure 3 shows a hierarchy of object "MIBChangeDetection" in the MIB structure.

Figure 4 is a flowchart of a method for polling changes in the network device using SNMP agent;

DETAILED DESCRIPTION OF THE INVENTION

The above mentioned and other features and objects of this invention will become more apparent and better understood by reference to the following detailed description. It should be understood that the detailed description made known below is not intended to be exhaustive or to limit the invention to the precise disclosed form as the invention may assume various alternative forms. On the contrary, the detailed description covers all the relevant modifications and alterations made to the present invention, unless the claims expressly state otherwise. The present invention will now be described with reference to figures 1-4. Referring to figure 1 , the present invention relates to a system for polling changes in a network device (10), the system comprising a management system (20) and a network device (10), characterised by: the network device (10) further comprises: a first storage (11) for storing current management information base (MIB) value of the requested MIB object instance in a MIB group; a second storage (12) for storing hash table, wherein the hash table comprises the current MIB value of the MIB object instance that has changed, and a second identifier that corresponds to MIB object identifier; a simple network management protocol (SNMP) agent (13) for receiving information request and detecting change; and wherein the network device (10) and the management system (20) are connected via a network (30).

In an embodiment of the system, the information request comprises a first identifier to identify the management system (20) that sends the information request and a second identifier to identify a MIB object instance within a MIB group.

In another embodiment, change detection is performed by the SNMP agent ( 3) and the SNMP agent (13) generating the hash table in response to the changes occurred within the MIB group. In an embodiment of the present invention, the hash table stores all the MIB values that have changed. The SNMP agent (13) may compare the current MIB values to the previous MIB values in the hash table in second storage (12) in order to determine if the current MIB value of the objects have changed.

The management system (20) in this present invention may be a network management system (NMS) or an element management system (EMS). In an embodiment of the present invention, the management system (20) periodically creates and sends the information request to the SNMP agent (13) to obtain changes update in the network device (10). As a result, network traffic can be reduced. In another embodiment, the management system (20) displays the changes in a graphical user interface (GUI). In an embodiment of the system in the present invention, the current MIB value in the first storage (11) that has changed will be stored as a hash table in the second storage (12) in "MIBChangesTable", which is also accessible to the management system (20).

The SNMP agent (13) performs SNMP and uses SNMP to receive information requests from the management system (20) and to respond to the information request over the network (30). The SNMP agent (13) may detect when values are changed within the MIB group.

In an embodiment of the present invention, in the first storage (11) in the network device (10), there is a hierarchy of MIB objects. Figure 2 and 3 shows an example of hierarchy of a MIB structure in the present invention. The hierarchy includes multiple levels of objects. Each object in the hierarchy has two names; a textual name called an object descriptor and a numeric object identifier, which indicates the object's place in the hierarchy. In addition to having the numeric object identifier, each object in the MIB may have a separate value. The values of some objects in the MIB may change over time. In the example shown in figure 2, each object identifier of each object in the hierarchy begins with ".1.3.6.1.4.1.13643.180.1" which is the MIB-identifying portion, followed by one or more other numbers which is the object-identifying portion. At the first level of the hierarchy, the next numerics object identifier in the object-identifying portion indicates the object's position among the other objects within the same level. The object "MIBChangeDetection" in figure 2 is in the fourth position in the first level of the hierarchy and has the numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4".

Herein, figure 3 will be used as an exemplary figure to explain the hierarchy of the MIB structure. As shown in figure 3, there are three objects in the first level of the hierarchy. The first object "MIBRequestTable" is assigned a numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4.1" to indicate it is in the first position among the other objects of the same level. The second object "MIBRequestCompleted" is assigned a numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4.2" to indicate it is in the second position among the other objects of the same level. The third object "MIBChangesTable" is assigned a numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4.3" to indicate it is in the third position among the other objects of the same level.

In the next subsequent level, the last number of the object-identifying portion indicates the position of the object among the other objects of the same level. For example, as shown in figure 3, the first-level object "MIBRequestTable" with numeric object identifier of " 1.3.6.1.4.1.13643.180.1.4.1" has one second-level object with numeric object identifier of M .3.6.1.4.1.13643.180.1.4.1.1". In the succeeding level, the second-level object "MIBRequestTableEntry" has three third-level objects. Each of the three objects in the third-level has numeric object identifier that begins with a sequence that matches the numeric object identifier of its parent in second-level object ".1.3.6.1.4.1.13643.180.1.4.1.1", but is followed by a number that indicates its position among other objects of the same level. As shown in the exemplary figure 3, the third-level object "MIBChangesTablelndex" with numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4.1.1.1" indicates that it is in the first position in the third-level hierarchy. The third level object "SNMPManagerld" with numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4.1.1.2" indicates that it is in the second position in the third-level hierarchy. The third level object "MIBGroupOID" with numeric object identifier of ".1.3.6.1.4.1.13643.180.1.4.1.1.3" indicates that it is in the third position in the third-level hierarchy.

In an embodiment of the present invention, the information contained within the hash table in the second storage (12) is actually stored within the MIB in the first storage (11) itself, and is not maintained separately from the MIB in the first storage (11). In the same manner, a selected object in the MIB in the first storage (11) may form the hash table in the second storage (12), although they are embodied within the MIB itself. Referring to figure 4, the present invention also relates to a method for polling changes in a network device using a simple network management protocols (SNMP) agent, the method is characterized by the steps of: receiving an information request from a management system (20) to start polling in the network device (10) (100), said information request comprising a first identifier to identify the management system (20) that sends the information request and a second identifier to identify a management information base (MIB) object instance within a MIB group; informing the management system (20) that the polling has started (200); collecting current MIB value of the MIB object instance identified via the second identifier and comparing said current MIB value against a previous MIB value (300); generating a hash table comprising the current MIB value of the MIB object instance that has changed, and the second identifier that corresponds to said MIB object identifier (400); storing the current MIB value of all the MIB object instances identified via the second identifier for future polling (500); and informing the management system (20) that the polling is completed (600).

In an embodiment of the present invention, the first identifier may be a SNMP Manager Identifier. In another embodiment of the present invention, the second identifier may be an Object Identifier of a MIB group.

In an embodiment of the present invention, the method for polling changes further comprises the step of the management system (20) querying the hash table to obtain the changes in the network device.

In an embodiment of the present invention, the step of informing the management system (20) that the polling has started (200) further comprises setting the information request flag to "False". In this embodiment, it is known to a person skilled in the art to use any suitable indication words or markers that define the setting of "False" and indicating that the polling has started. For example, it can be "start", "begin", "incomplete" or the like. In an embodiment of the present invention, the step of storing the current MIB value of all the MIB object instances identified via the second identifier is in regardless of the current MIB value has changed or has not. In an embodiment of the present invention, the step of informing the management system (20) that the polling is completed (600) further comprises setting the information request to "True". After setting the request to "True", the management system (20) may send the next information request to the network device (10) to poll for the next updated changes in the network device (10). In an embodiment of the present invention, it is known to a person skilled in the art to use any suitable indication words or markers that define the setting of "True" and indicating that the polling has completed. For example, it can be "end", "finish", "complete" or the like. Although the present invention has been described with reference to specific embodiments, it will be apparent for those skilled in the art that many variations and modifications can be done within the scope of the invention as described in the specification and defined in the following claims.

Claims

A system for polling changes in a network device (10), the system comprising a management system (20) and a network device (10), characterised by:

a. the network device (10) further comprises:

i. a first storage (11) for storing current management information base (MIB) value of the requested MIB object instance in MIB group;

ii. a second storage (12) for storing hash table, wherein the hash table comprises the current MIB value of the MIB object instance that has changed, and a second identifier that corresponds to MIB object identifier;

iii. a simple network management protocol (SNMP) agent (13) for receiving information request from the management system (20) and detecting change in the MIB group; and b. wherein the network device (10) and the management system (20) are connected via a network (30).

A system according to claim 1 , wherein the information request comprises a first identifier to identify the management system (20) that sends the information request and a second identifier to identify a MIB object instance within a MIB group.

A system according to claim 1 , wherein the management system (20) sends information request to the SNMP agent (13) in a periodically manner.

A method for polling changes in a network device (10) using a system comprising a management system (20) and a network device (10) having a simple network management protocols (SNMP), the method is characterized by the steps of: a. receiving an information request from a management system (20) to start polling in the network device (10) (100), said information request comprising a first identifier to identify the management system (20) that sends the information request and a second identifier to identify a MIB object instance within a MIB group;

b. informing the management system (20) that the polling has started (200);

c. collecting current MIB value of the MIB object instance identified via the second identifier and comparing said current MIB value against a previous MIB value (300);

d. generating a hash table comprising the current MIB value of the MIB object instance that has changed, and the second identifier that corresponds to said MIB object identifier (400);

e. storing the current MIB value of all the MIB object instances identified via the second identifier for future polling (500); and f. informing the management system (20) that the polling is completed (600).

A method according to claim 5, further comprises the step of the management system (20) querying the hash table to obtain the changes in the network device (10).

A method according to claim 5, wherein in the step of informing the management system (20) that the polling has started (200), the step further comprises setting the information request flag to "False".

A method according to claim 5, wherein in the step of informing the management system (20) that the polling is completed (600), the step further comprises setting the information request flag to "True".