Interface Message Processor (IMP)
Definition - What does Interface Message Processor (IMP) mean?
Techopedia explains Interface Message Processor (IMP)
A contract for the development of IMP was awarded to consulting company Bolt Baranek and Newman in 1968. What they developed essentially consisted of long-distance leased telephone circuits between pairs of IMPs. Host computers were connected to the IMP at the host site and network users were connected to their local host. A set of procols specified the conventions for communication between hosts connected to different IMPs.