September 2012

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When sizing communication links, especially costly satellite links, I am frequently asked to answer two questions.

  1. Given a carrier capable of x Mbps throughput, how many gigabytes could I transmit in one day?
  2. What is the minimum number of megabits per second (Mbps or Mbit/sec) necessary to transmit x gigabytes (GB) in one day?

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In “Internet Doom” news, RIPE estimates it is within one month of reaching its last /8 IPv4 allocation. As the CTO of an ISP, I regularly deal with overly-large IPv4 assignment requests from customers. You wouldn’t believe how many people think they need a /24 subnet for their Internet cafe. Most of the time this is simple ignorance, but sometimes it’s laziness too; they can’t be bothered to install a NAT-capable router for their PCs. We refuse these requests for the obvious reasons of IPv4 exhaustion, and for the less-obvious reason that you must be insane to leave a horde of pirated, non-patched Windows XP PCs on public IPs. I estimate the mean time to botnet infection to be less than 15 minutes.

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