A router that was a core router when introduced would likely not be a core router ten years later. Although the local area NPL network was using line speeds of 768 kbit/s from 1967, at the inception of the ARPANET (the Internet's predecessor) in 1969, the fastest links were 56 kbit/s.
A router that was a key component when introduced would probably not be a key component ten years later. The local area NPL network utilized line speeds of 768 kbit/s from 1967, whereas the ARPANET (the Internet's predecessor) began in 1969 with links at 56 kbit/s.