A method for testing of a communication network having a plurality of end-points, using one or more network agents coupled to the network at respective locations. The method includes specifying at least one packet filtering criterion, and transmitting one or more data packets meeting the at least one criterion through the network from one of the end-point to another. At least one of the data packets meeting the criterion is intercepted using the network agents at one or more of the respective locations in the network traversed by the at least one of the data packets. Information regarding the at least one intercepted packet at the one or more respective locations is recorded and processed to analyze a route of the at least one intercepted packet through the network.