It's pretty interesting to read into the original "broadcast" ethernet specs.
The "thick yellow wire" and the "coax" both had a single broadcast domain for all devices on the segment. You then linked segments with a bridge (so you could scale networks).
Some things I find interesting about them:
1) The idea is based on radio broadcast (ALOHANET). Since you're using radio broadcast there, a single collision domain makes sense. http://en.wikipedia.org/wiki/ALOHAnet. The protocol is best understood as "room full of people shouting at each other". Don't start talking if something else is, and if two people start at the same time, you both back off. Simple as that.
2) If two nodes try to transmit at the same time, you get a collision and both retry. The spec has a random retransmit timer to avoid immediate (and perpetual) recollision. Requires fair nodes...
4) It was (semi-)reasonable to use a "vampire tap" connector to dig through the insulation and into the core of a the "thick yellow" copper cable. Just don't wiggle it and cut the copper (or introduce too much of an edge and get signal reflection and hence more collisions).
5) When you had a copper connection between all the ports on your network, an etherkiller really meant something. (A cable, mains plug on one end, coax connecter on the other. Plug in and fry every network card on the segment). RJ-45 etherkillers are single-target. Pah.
Ethernet is still "broadcast" (CSMA/CD). It's just that now, with switched ethernet, the broadcast domain is reduced to the switch port and the station.
Comments
It's pretty interesting to read into the original "broadcast" ethernet specs.
The "thick yellow wire" and the "coax" both had a single broadcast domain for all devices on the segment. You then linked segments with a bridge (so you could scale networks).
Some things I find interesting about them:
1) The idea is based on radio broadcast (ALOHANET). Since you're using radio broadcast there, a single collision domain makes sense. http://en.wikipedia.org/wiki/ALOHAnet. The protocol is best understood as "room full of people shouting at each other". Don't start talking if something else is, and if two people start at the same time, you both back off. Simple as that.
2) If two nodes try to transmit at the same time, you get a collision and both retry. The spec has a random retransmit timer to avoid immediate (and perpetual) recollision. Requires fair nodes...
3) The max cable length and packet size and related via the speed of light (in copper): http://www.wildpackets.com/resources/compendium/ethernet/pro...
4) It was (semi-)reasonable to use a "vampire tap" connector to dig through the insulation and into the core of a the "thick yellow" copper cable. Just don't wiggle it and cut the copper (or introduce too much of an edge and get signal reflection and hence more collisions).
5) When you had a copper connection between all the ports on your network, an etherkiller really meant something. (A cable, mains plug on one end, coax connecter on the other. Plug in and fry every network card on the segment). RJ-45 etherkillers are single-target. Pah.
Ethernet is still "broadcast" (CSMA/CD). It's just that now, with switched ethernet, the broadcast domain is reduced to the switch port and the station.