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Comment by sshagent | Hacker News Reader

wow, I've not heard 'token ring' mentioned for a long long while.

In retrospect, what were Token Ring's downsides that caused it to lose?

Requiring shielded twisted pair cabling? Processor costs (when it mattered) and Ethernet's benefiting massively from cheap switches (when hardware costs had dropped)?

I understand it was all about cost and complexity, token ring was superior technically, but as ethernet prices dropped steadily over the years, and its cheaper collision detection approach turned out to usually be "good enough" (especially with the advent of smart switches that made collisions less of an issue), the balance switched in ethernet's favour.

Token ring cost 5-6 times as much, and required a special MAU device (the thing that sat on the ring). Then the actual networked computers had a point to point connection to the MAU. Special cabling, not just twisted pair. IBM charged a lot for anyone else to licence the tech.

Token ring was clever and worked well though - a heavily used 10Mbps token ring network was far faster than the equivalent ethernet network due to no collisions.

Also (and I was fairly young at the time), didn't token ring have some uglier failure modes? E.g. if if the token were lost due to bad cabling / misfunctioning devices?

Whereas ethernet degraded more gracefully.

Yes, that makes sense to me, not knowing too much about it. I found an interesting article about the various failure modes of token ring, and this is one (alongside the Captured or Corrupted token problems):

(ii) If Token is lost: To deal with such situations, it is the responsibility of Monitor to generate new Token. Monitor will wait for Max Token Return Time and if the token is not received then it will generate a new Token.

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