Joho the Blog » [reboot08] David Isenberg on the end of bandwidth limitations

[reboot08] David Isenberg on the end of bandwidth limitations

David Isenberg shows a fiber optic cable with 864 fibers. Each can carry 155 frequencies that each can carry 10 gigabits. That means three of the fibers can carry the entire busy hour traffic of the USA. If everyone on the planet had a phone and was making a call at the same time, that one cable could carry it, and 100 of the fibers would still be dark. [I'm sure I screwed up some of the numbers, perhaps seriously. Sorry. I'm multitasking because I decided this afternoon that my after dinner talk — entirely new — needs slides.] “The answer to the question ‘How many angels can dance on the head of a pin?’, the answer is ‘How many do you want to dance on the head of a pin?’.”

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4 Responses to “[reboot08] David Isenberg on the end of bandwidth limitations”

  1. David! I’m surprised you fall for this particular rhetoric.

    Three fibers can carry all of the busy hour traffic. But that traffic has to get to those three fibers, which means a nation worth of switching and distribution network, copper warming up with weak currents going through them, coax waving in the wind, fiber and microwave towers (in odd places) and who knows what else.

    Transmission capacity is not the issue here. It’s switching and routing (and billing) capacity. I guarantee you that it’s not free to have 3 * 155 * 10G worth of traffic divided up and routed exactly where it needs to go around the globe.

  2. ahhh… the voice of reason. the network’s internals are smarter than some of us would prefer.

  3. @ Ed V . . . Completely correct. The good Dr. Weinberger left out, “. . . and if all that traffic could magically get to this cable . . .” I was not trying to do network architecture, I was simply doing a thought experiment about how much capacity could be there. It’s like if I said, “If oranges were solar systems, how big would the galaxy be?” I wouldn’t intend this to be a lesson in cartography.

    Oh, by the way, the current off-the-shelf equipment does 160 wavelengths times ten gbit. And it is not free. But it is diminishingly inexpensive per bit, and these prices are falling approximately with Moore’s Law.

  4. Most hosting companies advertise 5TB for $5/month or whatever they are claiming now, but they will kick you off your shared server before you get anywhere near 1TB, not because you ran out of bandwidth but because the CPU and disk can’t keep up. What you’re paying for these days is time on the CPU and disk, which is why “grid” hosting is so attractive now.

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