4 ms·
I remember working at IBM, token ring was the protocol du jure. Someone told me about this crazy non-IBM protocol where you just shoved data into the wires. If
by beachy 5y ago
I remember working at IBM, token ring was the protocol du jure.
Someone told me about this crazy non-IBM protocol where you just shoved data into the wires. If it collided with someone else's data - just try again!
Thanks to a good helping of fud, there was no doubt in my mind that this was a rubbish approach that wouldn't scale (though obviously it was pretty handy not having to wire your network into a ring configuration).
- sshagent 5y agowow, I've not heard 'token ring' mentioned for a long long while.
- ethbr0 5y agoIn 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)?
- beachy 5y agoI 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.
- ethbr0 5y agoAlso (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.
- beachy 5y agoYes, 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.