PDP-11 had a little endian architecture while big endian machines like the PDP-6/PDP-10 predominated on the net.

To make life more interesting, the later PDP-10/20 mainframes used PDP-11 minicomputers as front end processors and often as network processors so byte-swapping was the norm. Luckily the PDP-10 allowed bytes ranging from 1-36 bits wide - “byte” had not yet standardized on 8 bits

Not that strange — it was really the successor of the PDP-11, which was a quite different architecture.

Could Dave Cutler have foreseen ... nahhh!