1. A method for classifying traffic in a communication network, the method comprising: receiving a traffic activity graph, the traffic activity graph comprising a plurality of nodes interconnected by a plurality of edges, where each of the plurality of nodes represents an endpoint associated with the communication network and each of the plurality of edges represents traffic exchanged between a corresponding pair of the plurality of nodes; generating an initial set of inferences as to an application class associated with each of the plurality of edges, based on at least one measured statistic related to at least one traffic flow in the communication network; and refining the initial set of inferences based on a spatial distribution of the at least one traffic flow, to produce a final traffic activity graph.