Ethernet, Aloha and CSMACD was: RS485 CSMACD protocol

The token ring advocates always pointed out how certain circumstances could lead to collision detection not working nicely. They were also extremely unconfortable with the lack of guaranteed bandwidth for each master etc.

But the token ring vs collision detection wars for general-purpose networking were fought and token ring lost. In real life the concerns that the token ring advocates had about collisions just don't happen, even on highly saturated ethernets.

Now, you can make up some really stupid collision detection-back-off algorithms that just don't work. CSMA-CD can be stupidly implemented such that it doesn't work well. Usually these implementations were done by committees who thought too hard about a simple problem and worked hard to come up with an insane list of requirements. I think the original poster was looking to avoid such mistakes by asking for example code that does things the right (not wrong) way.

Curiously I've seen CSMA-CD done the "wrong way" most often when the committee designing it has a lot of token ring advocates on it. They add all sorts of arbitrary and unnecessary requirements about guaranteed bandwidth etc. and make the result useless.

Token ring still lives on in many special-purpose protocols, not necessarily because collision detection won't work but just because it wasn't used.

Tim.