Abstract: When testing network management applications, it is desirable to show that they will work with large or very large networks, to determine the upper bounds of the applications capabilities, and improvements which might increase the upper bounds. A method of testing a network application is disclosed mapping a layer-3 addresses of a real subnetwork onto a plurality of mapped layer-3 subnetwork addresses for conversations with applications or devices. Packets are modified to change a destination layer-3 address in a mapped subnetwork, pointing to corresponding real IP address and forwarding the packets. The conversation to which a response from a reallayer-3 address relates is identified. The source layer-3 address and packet contents are changed into the appropriate mapped subnetwork and the packet is forwarded to the application or device. An existing test network of any size may be used as the basis for testing the network management application.

Abstract: A method and apparatus for determining a time interval for periodically polling a device on a network 1 is described. The method determines the most restrictive link on the path to the network device, the level of restrictiveness of a link being dependent on the nature of the link, such as the link speed and link type. The time interval between polling is determined based on the nature of the most restrictive link. Thus, the time interval can be determined according to the type and speed of the links between the polling device, which in a preferred embodiment is a network management station, and the polled device on the network 1.

Abstract: It is desired to test network management applications, for example, to show that they will work with large or very large networks, to determine the upper bounds of the applications capabilities, and to determine improvements which might, for example, increase the upper bounds. A method of testing a network application is disclosed providing a mapping of the layer-3 addresses of a real subnetwork onto a plurality of mapped layer-3 subnetwork addresses for conversations with the application or device. A packet is modified to change a destination layer-3 address in a mapped subnetwork, to point to the corresponding real IP address and the packet is forwarded on. The conversation to which a response from a reallayer-3 address relates is identified. The source layer-3 address and packet contents are changed into the appropriate mapped subnetwork and the packet is forwarded to the application or device.

Abstract: A method and apparatus for identifying a device acting as a server on a network is disclosed which uses network data representing communications on the network. The network data contains source device, destination device, data transfer protocol and data volume information for each communication represented therein and may be collected by network traffic monitors or packet capture devices such as RMON2 probes on the network. Data relating to relevant server protocols is identified within the network data, and using the identified data, a device is determined to be acting as a server if it has the highest data volume for communications in which it is the source or destination device and which communications involve at least a threshold number of other devices. The method may be conveniently implemented in a computer program and may be used in conjunction with a network management application.

Abstract: Apparatus and method for use in a network of, for example, computers, for generating summary data, such as traffic summary information, from a plurality of data records, the data records having a different temporal basis, for example, one hour or one day or one week, and different start and end times. The summary data is generated for a requested time interval having a requested start time and a requested end time by selecting a data record with a record start time corresponding to the requested start and an end time as far as possible from the record start time but equal to or before the requested end time. The data from that selected data record is processed, and the initial time is then set to the end time of that particular data record and the process repeated. In this way one can gather and process such data with a minimum number of steps.

Abstract: A method and apparatus for determining a time interval for periodically polling a device on a network 1 is described. The method determines the most restrictive link on the path to the network device, the level of restrictiveness of a link being dependent on the nature of the link, such as the link speed and link type. The time interval between polling is determined based on the nature of the most restrictive link. Thus, the time interval can be determined according to the type and speed of the links between the polling device, which in a preferred embodiment is a network management station, and the polled device on the network 1.

Abstract: A method of monitoring a network of devices comprising defining at least two types of device, and monitoring the different types of device using different monitoring procedures, either interrogating said devices at different intervals or interrogating said devices using different protocols .The defined types of device comprise core devices and edge devices. The method also comprises determining the number of devices in the network to be monitored, and changing the monitoring intervals for each type of device in accordance with the determined number.