US 6701327 Merging network data sets comprising data acquired by interrogation of a network

ABSTRACT – A method for providing a data set relating to a network by merging a first data set relating to the network at a first time and a second data set relating to the network at a s second, later, time, said first data set comprising data acquired by interrogation of the network and other data, and said second data set comprising data acquired by interrogation of the network, said method comprising: comparing the data in the first data set with the second data set, and updating the first data set to include additional data present in the second data to set which is not present in the first data set.

BACKGROUND OF THE INVENTION

The present invention relates to merging network databases. Network databases are used in supervising a network, that is a network of electronic devices comprising, for example, workstations, personal computers, servers, hubs, routers, bridges, switches, (hereinafter referred to as devices of the network), and links between these devices which may be in the form of physical cable or wireless links. The network may be a local area network (LAN), wide area network (WAN) or other types and may operate in accordance with any desired protocol.

After such a network has been installed, it is desirable for the person appointed network manager to be able to understand the technical operation of the network. In known network management systems, the manner in which the relevant data is retrieved from the managed devices, compiled and displayed has been problematic in several respects. Firstly, the data received from each of the managed devices is simply compiled and displayed as a list of data for the user to interpret. Secondly, the data does not provide information about unmanaged devices. Thirdly, information about a given network device, such as the type of device, location of the device on the network and operating speed of the device, may be contained in different sections of the compiled data. Consequently, conventional systems are cumbersome and difficult to use.

In co-pending UK patent applications numbers 9910843.3, 9910844.1, 9910845.8, 9910838.3, 9910837.5, 9910839.1, 9910840.9, 9910962.1 (each in the name of the assignee of the present application) which are incorporated herein, we describe various arrangements for providing automatic interrogation of the network to thereby produce a network map which may be displayed on a visual display unit showing the devices and links between the devices a data set with details of the network and devices. At its simplest, and where the device is a “managed” device, this interrogation uses a known protocol, such as the SNMP protocol, of the so-called ‘agent’ of each device which stores the devices unique MAC address, data relating to the type of device and the MAC addresses of the devices which are connected to the ports directly or indirectly.

Once this information is ascertained, it may be stored, for example, on the network manager’s work station and used for various purposes. Interrogation of all the devices in the network will usually be carried out relatively infrequently.

Between these interrogations, there may be changes to the physical network itself or to the data set. For example, the network manager using his own knowledge may have manually added to the network data set non-managed devices which cannot be interrogated in the same way as managed devices, and may also have manually inserted known links between devices. Furthermore, devices and links may have been altered (ie added, removed, moved, increased or decreased in capacity). Over the course of time, therefore, the network data set may change substantially from its generation by the previous interrogation of the network.

At a later date, it may desired to interrogate the network again to verify or extend the network data set, and unless all of the earlier information is to be discarded, it is desirable to provide a system to deal with the differences between the newly generated (second) network data set, and the (first) network data set which the network manager already has. In particular, it is desirable not to discard information in the first data set which cannot be shown to be incorrect or not present (eg the information manually added by the network manager). Whilst the network manager can consider each device and link individually and compare them from the two network data sets, and make a decision, it is clearly desirable to be able to produce some kind of system or algorithm to enable the comparison to be carried out by means, for example, of a program running an algorithm on the network manager’s computer.

Thus in general terms, the present invention relates to merging one set of data representing a network, into another set of data representing the same network, but that was constructed at a different time to the first data set. The problem to be resolved is how to deal with the similarities and differences between the two sets of data.

SUMMARY OF THE INVENTION

The present invention relates to merging network databases.

The present invention provides a method for providing a data set relating to a network by merging a first data set relating to the network at a first time and a second data set relating to the network at a second, later, time, said first data set comprising data acquired by interrogation of the network and other data, and said second data set comprising data acquired by interrogation of the network, said method comprising:

comparing the data in the first data set with the second data set, and

updating the first data set to include additional data present in the second data set which is not present in the first data set.

In this way the information, usually the information which has been added by the network manager subsequent to the initial interrogation of the network, is preserved in creating the new data set.

Furthermore, said updating step may include the step of deleting from the first data set that data where the second data set includes information that the aspect that said data relates to is no longer present in the network.

By this method step, information which has changed and is incorrect is deleted from the first data set.

The present invention also provides a computer program on a computer readable medium or embodied in a carrier wave for use in providing a data set relating to a network by merging a first data set relating to the network at a first time and a second data set relating to the network at a second, later, time, said first data set comprising data acquired by interrogation of the network and other data, and said second data set comprising data acquired by interrogation of the network, said program comprising:

program means for comparing the data in the first data set with the second data set, and

program means for updating the first data set to include additional data present in the second data set which is not present in the first data set.

A preferred embodiment of the invention will now be described by way of example and with reference to the accompanying drawings in which;

FIG. 1 is a diagrammatic view of a network incorporating a preferred embodiment of the invention,

FIGS. 2 to 8 show a series of possible links between ports of two network devices, the left part of each drawing showing the link established in a first set of data representing a network (ie the first network map) and the right part of each drawing showing the link detected during later interrogation to produce a second, later, network map,

FIG. 9 is a flow chart for merging discovery data,

FIG. 10 is a flow chart for merging sizing data, and

FIG. 11 is a flow chart for merging topology data.

 

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