In one embodiment, a node-implemented method for performing analysis of traffic within a packet communications network. First, the node measures a traffic aggregate at specified nodes within the network with regard to a packet set of interest. Each traffic aggregate (i) is a set of packets, observed at one of the specified nodes, having a common characteristic and (ii) is measured at one of the specified nodes by creating a digest for the packets having the common characteristic. The digest characterizes the traffic aggregate without containing the actual packets themselves. Next, the node formulates an intersection set cardinality determination for a network traffic-characterizing parameter to be measured in the network utilizing the digests characterizing the traffic aggregates. Next, the node solves the set cardinality determination for the network traffic-characterizing parameter to be measured.