> and unlike Ethernet, all the cards on the ring had to talk at the same speed.
Essentially that was the same for Ethernet too, everything on the same leg needs to talk at the same speed, though IIRC a different speed device wouldn't take down everything, it would just cause a significant excess of collisions due to the out-of-sync cross-talk and not be able to talk to anything itself. It wasn't until switching hubs and full switches were around that you could mix speeds on the same leg (with a switching hub you'd actually have two legs, one at each speed, bridged, with a full switch you have a separate collision domain per port so can mix speeds quite freely).
We used to love token ring style networks (specifically ARCNET) for playing Doom, Descent and Quake back in the day. ARCNET was more annoying to set up and had thicker cables, but it was rock-solid reliable afterwards. Totally bulletproof.
In comparison to that, traditional ethernet (think concentric cabling and terminators) glitched often and one flaky part of a cable could ruin your day.
ARCNET was much slower in theory, but robust, fair and stable and did not totally die under load from a single client.
Token-passing networks were interesting for hard real time system analysis, as they featured deterministic access control instead of collision detection. They made possible extending Rate Monotonic Scheduling theory to the network layer as well. The priority work (priority ceiling protocol, multi level token priority schemes) survive today in token bucket rate limiting.
The "WAS" in that title just made me feel really old. I remember learning about this in college and it being a thing that I would need to work with and understand how it works why it's different than ethernet. And now it's just a big "WAS".
Token Ring was a networking alternative to Ethernet.
With Ethernet when a node wants to transmit it just does so, then backs off and retries if there was a collision (someone else trying to transmit at the same time).
Token Ring avoided collisions by passing a "permission to transmit" token from node to node in circular (ring) fashion.
My local hospital system (Premier Health) was all-in on IBM and token ring. I remember being chagrined when they built a new hospital in 1998 and wired everything for token ring. The writing was clearly on the wall for token ring by 1998 but their IT department bled IBM blue.
Fast-forward to 2013, when my wife was giving birth to our daughter in one of their hospitals, and I noticed an unused type-1 token ring wall jack in our room right beside some occupied 8P8C (aka RJ-45) jacks.
> and unlike Ethernet, all the cards on the ring had to talk at the same speed.
Essentially that was the same for Ethernet too, everything on the same leg needs to talk at the same speed, though IIRC a different speed device wouldn't take down everything, it would just cause a significant excess of collisions due to the out-of-sync cross-talk and not be able to talk to anything itself. It wasn't until switching hubs and full switches were around that you could mix speeds on the same leg (with a switching hub you'd actually have two legs, one at each speed, bridged, with a full switch you have a separate collision domain per port so can mix speeds quite freely).
We used to love token ring style networks (specifically ARCNET) for playing Doom, Descent and Quake back in the day. ARCNET was more annoying to set up and had thicker cables, but it was rock-solid reliable afterwards. Totally bulletproof.
In comparison to that, traditional ethernet (think concentric cabling and terminators) glitched often and one flaky part of a cable could ruin your day.
ARCNET was much slower in theory, but robust, fair and stable and did not totally die under load from a single client.
Token-passing networks were interesting for hard real time system analysis, as they featured deterministic access control instead of collision detection. They made possible extending Rate Monotonic Scheduling theory to the network layer as well. The priority work (priority ceiling protocol, multi level token priority schemes) survive today in token bucket rate limiting.
The "WAS" in that title just made me feel really old. I remember learning about this in college and it being a thing that I would need to work with and understand how it works why it's different than ethernet. And now it's just a big "WAS".
Short version:
Token Ring was a networking alternative to Ethernet.
With Ethernet when a node wants to transmit it just does so, then backs off and retries if there was a collision (someone else trying to transmit at the same time).
Token Ring avoided collisions by passing a "permission to transmit" token from node to node in circular (ring) fashion.
My local hospital system (Premier Health) was all-in on IBM and token ring. I remember being chagrined when they built a new hospital in 1998 and wired everything for token ring. The writing was clearly on the wall for token ring by 1998 but their IT department bled IBM blue.
Fast-forward to 2013, when my wife was giving birth to our daughter in one of their hospitals, and I noticed an unused type-1 token ring wall jack in our room right beside some occupied 8P8C (aka RJ-45) jacks.
https://web.archive.org/web/20261016122640/https://dfarq.hom...
Summary: Something that coulda been really cool & awesome, if not for crappy decisions made by the Dark Lord...er, I mean IBM.
Lot more details: https://en.wikipedia.org/wiki/Token_Ring
Token Ring was always a bad idea, even before IBM screwed it up. Tanium still does this crap and it's awful.