Among the basic assumptions made by the IMP Guys was that the most effective way of detecting failures was through an active reporting mechanism. They designed their system so that each IMP periodically compiled a report on the status of its local environment—number of packets handled by the IMP, error rates in the links, and the like—and forwarded the report through the network to a centralized network operations center that BBN had set up in Cambridge. The center would then integrate the reports from all the IMPs and build a global picture of the most likely current state of the network.
