Ethernet prevails because it is dumb. There was time even to put human operators into the loop, and a need to concentrate programming at one central location. But in the emerging world of supercomputers in your pocket or living room, networks will have to be dumb bandwidth pipes. What the coming array of desktop supercomputers and cheap massively parallel servers will need is passive dark fiber, mostly unlit by switching intelligence. Dark fiber can allow for the huge variety of data forms and functions, protocols and modulation schemes that is emerging in the new era of convergence between phones and computers.
Ethernet is the protocol for a dumb pipe, a passive ether.
That is why it fits so well on a cable TV line and why it will fit even into the multigigabit world of a multimedia future. The Return of Aloha The dumb networks of the fibersphere will be ethernets. In these networks, fiber changes from a substitute for copper to a substitute for air. Just as the microcosm put entire computer systems on single slivers of silicon, the telecosm will put entire communications systems on seamless webs of silica. As chips and fiber are hugely expanding their performance and bandwidth, information traffic is rapidly migrating from the wires to the air.