Xerox and DEC were early players in the ethernet scene. XNS (Xerox Network System) formed the basis of the early ethernet implementations. I was implementing such systems commercially in about 1983. ICL had company wide network at the time. IBM of course refused to accept anyone else's standards and came up with their utterly hopeless token ring system. - "some of our tokens are missing" was often the despairing cry in network Support. The mainframe suppliers including ICL were determined that the mainframe would remain king and control the network and of course they were ultimately proved totally wrong.
I first came across TCP in about 1983/4 with a bespoke office system when Mini's first appeared. Can't remember what it was called but dumb terminals hung of the central system which provided e-mail, word processing and a few applications. Spreadsheet database and the like. This is what I was told at the time. TCP or Transaction Control Program, was produce by General Motors as part of a batch system to control demand and supply of parts around their production lines. You know the sort of thing - punched cards input and pages and pages of printout of which only about two were relevant. Then they went to interactive input and TCP/IP was born - the IP bit stranding for interactive protocol. I can't vouch for this other than it's what I was told in marketing briefings.
ICL took the system and transferred it to UNIX and sold it as Officepower. No idea how many they sold. I put one into Sandwell Hospital in Birmingham.