By comparing actual throughput, the theoretical bandwidth between the transmitter, receiver or, a measurement taken at an earlier date, you can tell whether the network is operating as expected. Variations in throughput may indicate a significant amount of other traffic, overloaded network equipment, communication errors which cause packets to be lost or, in the case of wireless networks, interference from other wireless devices. By performing tests using different machines on the network then you begin to gain clues as to where the problem lies, which areas should be examined in greater detail. - NetStress :: Network Benchmarking Tool