Abstract: The present invention provides a method of operating a network comprising the steps of: analyzing a first datastore comprising data representing historical network performance; creating or more indices within the first datastore; creating one or more probability networks in accordance with one or more of the created indices; determining from the one or more probability networks a conditional probability associated with an alarm event; and' if the conditional probability determined is less than a threshold value, disregarding the associated alarm event; or if the conditional probability determined is greater than a threshold value, using the associated alarm event in conjunction with other historical network data to predict future alarm events.

Abstract: Methods and systems for deriving measures indicative of application-level quality of service in relation to a client application operating in a data network whereby application data of relevance to the client application is transmitted in packets from node to node over the network by means of a plurality of application flows, each application flow being an exchange of dat between the client application and a serving application; the method comprising: monitoring characteristics of packets containing application data of relevance to the client application and identifying an application flow associated with each packet; determining from monitored characteristics, according to predetermined criteria and individually in relation to each of a plurality of application flows associated with the client application, a flow-level performance measure; and collating the respective flow-level performance measures and deriving an application-level service-quality measure.

Abstract: The present invention provides a method of operating a network comprising the steps of: analysing a first datastore comprising data representing historical network performance; creating or more indices within the first datastore; creating one or more probability networks in accordance with one or more of the created indices; determining from the one or more probability networks a conditional probability associated with an alarm event; and' if the conditional probability determined is less than a threshold value, disregarding the associated alarm event; or if the conditional probability determined is greater than a threshold value, using the associated alarm event in conjunction with other historical network data to predict future alarm events.

Abstract: Methods and systems for deriving measures indicative of application-level quality of service in relation to a—client application operating in a data network whereby application data of relevance to the client application is transmitted in packets from node to node over the network by means of a plurality of application flows, each application flow being an exchange of dat between the client application and a serving application; the method comprising: monitoring characteristics of packets containing application data of relevance to the client application and identifying an application flow associated with each packet; determining from monitored characteristics, according to predetermined criteria and individually in relation to each of a plurality of application flows associated with the client application, a flow-level performance measure; and collating the respective flow-level performance measures and deriving an application-level service-quality measure.

Abstract: An information access system is provided to create and maintain a rapidly accessible index to information extracted from information sources accessible over the Internet. The information access system may be tailored to extract, analyse and index information obtained via the public query interfaces to a number of predetermined information databases. Information may be extracted from the information databases by submitting appropriate query requests to their query interfaces and analysing data returned in response. Query requests may be stored and maintained by the information access system in query files. Query responses may be analysed by one or more query result analysis modules, each module being tailored to convert information supplied by a particular site into a common format for storage in an index. New information may be identified and reported to users. The information access system may be applied, in particular to commercial property trading.