Its functions were to gather traffic information as a basis for improving internet performance, and to detect security incidents.
It fed into "IST 2.3.5 Research Networking testbeds", which aimed to contribute to improving internet infrastructure in Europe.
Instead of collecting flow-level traffic summaries or actively probing the network, passive network monitoring records all IP packets (both headers and payloads) that flow through the monitored link.
MAPI enables application programmers to express complex monitoring needs, choose only the amount of information they are interested in, and therefore balance the monitoring overhead with the amount of the received information.
The LOBSTER sensors operated by the various organisations monitored the network traffic using different measurement applications.