Paul, can you put that document up somewhere? It would be an interesting read.
Sent from my iPhone > On Oct 16, 2025, at 07:12, Paul Koning via cctalk <[email protected]> > wrote: > > > >> On Oct 15, 2025, at 7:14 PM, Doug Jackson via cctalk <[email protected]> >> wrote: >> >> Ethernet also got *way* more market traction, because it was >> infinitely more survivable. >> >> One of my early jobs was managing a Token Ring network, and we spent our >> days running around a 13 floor building, chasing machines where people had >> kicked connectors out of walls, just enough to stop data, but not enough to >> make the MAU do the self isolation. We had a piece of software called the >> Cabletron TR Manager - that monitored the ring for beaconing, and let us >> know the upstream node that detected the break. Then we would consult our >> *detailed* notes on what cards were installed where, so we could find the >> culprit that was broken. Without the notes, we would have had zero chance. > > FDDI was somewhat better. It's not all that well known, but IBM (802.5) > token ring and FDDI have essentially nothing in common. At DEC when we were > working on its development we liked to say that the only things in common are > "token" and "ring". Actually, FDDI is in a sense an evolution of 802.4, of > all things. > > I also remember while there kicking around the notion that we could take the > FDDI signaling scheme (4b/5b code) and use it to send Ethernet packets. That > worked quite well and the rest is history... > >> >> Heady days. >> >> I suggested to the network manager at the time that we could transition >> from TR to Ethernet (everything was wired with Cat3 Shielded cable - but he >> didn't want to, because "Ethernet had collisions" - that was when I >> discovered that everybody has limitations that something breaks their >> thinking. After a while I convinced him to transition one of the Cabletron >> cards to Ethernet, and do a test on a 32 workstation card - Suffice to say >> that those 32 machines never had an issue, and eventually, all 800 machines >> across two rings were transitioned to 100Mb Ethernet. > > Around that time, IBM put out a marketing document that pretended to show why > token ring was better than Ethernet. The DECnet architecture group (where I > worked at the time) created a paragraph by paragraph rebuttal to that and > published it as a joint DEC/3Com document. I still have it: "The > Digital/3Com Guide to IBM document # GG22-9422-0" (DEC document > EE-EA345-42-001). It doesn't seem to be online, Google has never heard of > it, nor the IBM document it rebuts. As I recall, Bill Hawe was the lead > author of that work; I wrote some bits and pieces for it but I don't remember > the details. > > paul
