We argue that the network is actually an extension of the system unit; therefore we should be able to use network traffic generated by a node to ascertain the state of its various internal components. We demonstrate that this approach is feasible for passive resource discovery, and is also applicable to a variety of other resource characterization applications such as remote monitoring, and network intrusion detection. Это и многое другое вы найдете в книге Resource Discovery: Using Network Traffic To Infer CPU And Memory Load (Lanier Watkins)