A method of testing a network (190, 290), comprising: identifying a plurality of tracking factors (1102, 1104) for categorizing and consolidating test statistics, each tracking factor having a plurality of possible values generating a plurality of global flow identifiers, the plurality of global flow identifiers including a unique global flow identifier corresponding to every possible combination of values for the plurality of tracking factors (1102, 1104) identifying a port-specific subset of the plurality of global flow identifiers to be received at each destination port unit of a plurality of destination port units generating a port-specific packet group identifier map (630, 930) for each destination port unit to compress the respective subset of global flow identifiers to a corresponding plurality of packet group identifiers, hereinafter called PGIDs one or more source port units transmitting a plurality of packets (300, 600) over the network (190, 290), each packet including a PGID one or more of the destination port units receiving the packets (300, 600) via the network (190, 290), each destination port unit extracting the PGID from each received packet accumulating traffic statistics for each of the plurality of PGIDs using the respective port-specific PGID map (630, 930) to associate each PGID with the corresponding global flow identifier aggregating the accumulated traffic statistics for at least some of the plurality of global flow identifiers to generate aggregated traffic statistics based on a first tracking factor selected from the plurality of tracking factors (1102, 1104). identifying a plurality of tracking factors (1102, 1104) for categorizing and consolidating test statistics, each tracking factor having a plurality of possible values generating a plurality of global flow identifiers, the plurality of global flow identifiers including a unique global flow identifier corresponding to every possible combination of values for the plurality of tracking factors (1102, 1104) identifying a port-specific subset of the plurality of global flow identifiers to be received at each destination port unit of a plurality of destination port units generating a port-specific packet group identifier map (630, 930) for each destination port unit to compress the respective subset of global flow identifiers to a corresponding plurality of packet group identifiers, hereinafter called PGIDs one or more source port units transmitting a plurality of packets (300, 600) over the network (190, 290), each packet including a PGID one or more of the destination port units receiving the packets (300, 600) via the network (190, 290), each destination port unit extracting the PGID from each received packet accumulating traffic statistics for each of the plurality of PGIDs using the respective port-specific PGID map (630, 930) to associate each PGID with the corresponding global flow identifier extracting the PGID from each received packet accumulating traffic statistics for each of the plurality of PGIDs using the respective port-specific PGID map (630, 930) to associate each PGID with the corresponding global flow identifier aggregating the accumulated traffic statistics for at least some of the plurality of global flow identifiers to generate aggregated traffic statistics based on a first tracking factor selected from the plurality of tracking factors (1102, 1104).