First commercial Ethernet media (1980) also was a RG-8X coaxial cable using the circa-1940 RF connector called “N” (as opposed to the F or the unthreaded RCA ph

First commercial Ethernet media (1980) also was a RG-8X coaxial cable using the circa-1940 RF connector called “N” (as opposed to the F or the unthreaded RCA phono connector). You could then do “simple” vampire tap into such Ethernet RF cable to expand your network. Because the then-10Base-5 signal is a guided RF-based wire, it was originally made to allow communication in one-direction only … at a time (half-duplex). Each end of the wire had to wait their turn (just like telegraph operators did by beaconing their intent to send info by pre-sending some well-known code). Both IBM and Xerox Parc diverged into Token Bus and Star network configuration to deal with this “half-duplex” issues using the same collision backoff algorithm. I think David unknowingly cemented the IEEE 802.3 standard as a winner when he prototyped the N-backoff algorithm for upcoming 802.3 for the 802 IEEE Working Group. This half-duplex constraint of 802.3 (and 10Base-5) technology was losing out to the IBM token bus (IEEE 802.5) methodology in maximum bandwidth utilization. Of course, without this N-Backoff algorithm, 802.3 wouldn’t have made the next step of leveraging a twisted pair (precursor to 802.3 10Base-T) possible to achieve this full-duplex and modern Ethernet we know to this day. Token bus and token ring both had effectively lost out in the Ethernet “Duplex War”. While Bob Metcalf may have made it possible the 10Base-5 communications, he also got a lot of hardware help so David Bogg actually did the thinking of backoff algorithm … at hardware level. And the PARC performance team refined the backoff algorithm to near perfection. Any error are mine and mine alone. I was close enough to that circle, others may be closer.