A little piece of Internet/BBN history from that era -- BBN Report 4825, QTR #23, dated November 1981. Section 5.1 is titled "Gateway Development". It is part of Section 5 which is titled "Internet Operations and Maintenance" It says in part:
"During this quarter, responsibility for all gateway maintenance and development was transferred from the Information Sciences Division to the Computer Systems Division (now Communications System Division). The motivation for this transfer was the need to emphasize the treatment of the gateways as an operational communications system, rather than a research tool to support the growing user community. In this approach, we plan increasingly to treat the gateway system much as we do the ARPANET and SATNET systems in terms of monitoring and maintenance."
I was on the receiving end of this transfer, so I then had the responsibility for effecting that change in direction and managing the efforts going forward to make the Internet operational. After the change, the "Gateway group" was literally down the hall from the "Arpanet group". I think this was the point where the "Arpanet DNA" began to strongly influence the evolution of the gateways which formed the early Internet, as we began to change the hardware and software to make it more manageable and reliable and more like the Arpanet, which had already proven the techniques. Before long, all of the "core gateways", as well as the Arpanet IMPs and SATNET SIMPs, were being operated and managed by the same NOC at BBN.
One might note this as the point in time where the Internet stopped being a pure research tool and started being a communications utility. I'm not sure who invented The Internet, but I think it was "turned on" sometime in the quarter of August/September/October 1981.
All of this was government funded. The full report is available online from DTIC - http://www.dtic.mil/dtic/tr/fulltext/u2/a108783.pdf