Token Ring - Only good in theory...

The basic operational theory behind Token Ring is great. Invented in the 1970's by a guy who was standing in a Ring of people Tokin on a joint - some weird stonie rule where only the guy with the joint (token) could speak. He'd take a hit, say something profound, then pass the joint to the next guy who would repeat the process until the joint made it around the circle. (I have heard this is actually a true story)

He realized it would be a way killer idea for networking - pass a logical token around machines on a network - only the machine with the token is allowed to communicate.

Ethernet, on the other hand, is based on the concept that anybody can talk as long as no one else is talking, but if more than one person talks at the same time, then they stop, think of a random number, count to that random number, listen to see if anyone else is talking, if no one else is, then they can talk. But there's always the chance that two people will start talking at the same time, and then the whole 'count to a random number' thing has to start all over again.

Works fine in small groups, but imagine it amongst a large number of people, or where there is some asshole who keeps interrupting, or some idiot that just keeps chattering senselessly...

Some moron network engineers use ethernet bridges, which is akin to joining two (or more) rooms of people operating under the same speaking rules (aka communication protocol) by connecting them via a speaker phone. Just makes the problem worse.

Good engineers use an ethernet switch, which connects people directly to each other similar to passing around several pairs of tin cans connected by string, so that many conversations can take place under the original "don't interrupt" rules, but only two people actually communicating at the same time, with only two, the chances of each other interrupting each other become very small.

Back to token ring, while it sounds good on the surface, small wiring problems can trigger network-wide problems, very hard to track down. Say people are standing around pasing the joint around the circle, and one gets too stoned and forgets to pass the joint to the next person, communication comes to a standstill. Or, the token gets passed to someone that doesn't know what to do with it (Like passing it to a cop or an old lady) - The token is lost. Or, half the circle forms a second circle, leaving out the other half, then only half of them can communicate.

In the wiring world, you can get a break in the wiring. Once break is OK - if the person can't hand the token off to the next person, then they hand it back to the person they got it from, assuming they know what to do with it. In this case, the token passes from one end of the "horseshoe" to the other end and back again. Communication is still possible, only not as efficient, especially if you are near one of the ends.

But, what happens if another break in another wire happens? The token will just bounce back and forth beween those two breaks, and everyone else is left out.

In the wiring world, it's a bitch - think of all the individual desktops you are going to have to visit with a continuity checker before you find the broken link? Sucks, don't it?

Token ring sucks, big time. Just sit in your ethernet, smoke your own joint, and hope nobody interrupts! :)

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