Patent ID: 8259578

Claim:
A method of determining a correction factor for use in monitoring network traffic traversing a network, said network traffic comprising a plurality of flows of data units, each of said flows having associated therewith a flow identifier from a set of flow identifiers, said data units having associated therewith a path characterisation metric; said method comprising the steps of: selecting, using a network node, a subset of flow identifiers from said set of flow identifiers; determining, in respect of flows having associated therewith flow identifiers from said selected subset of flow identifiers, which flows if any are of a first type and which flows if any are of a second type in dependence on an accumulated measure of the path characterisation metrics associated with data units of said flows, flows being determined to be of a first type in the event that their respective accumulated measure is within a first range, and flows being determined to be of a second type in the event that their respective accumulated measure is within a second range; determining a first measure of the total of the accumulated path characterisation metrics associated with data units of said selected subset of flows; and determining a second measure indicative of the proportion of said first measure contributed by flows of said second type; and determining a correction factor in dependence on the first and second measures.