SDN: It's Like DNS for Packet Switching
An article by the incomparable Lori MacVittie makes an interesting high-level comparison between DNS and software-defined networking.
Basically, the problem distills down to "I need to send information to this IP address. Where should I send it?" Which, if you think about it, isn't all that different from DNS, which basically says, "I need to send information to this host. Where should I send it?"
…In general, the benefits of DNS (which handles more database queries in a day than any other system on the planet) when abstracted and applied to a much smaller - yet increasingly similar in volatility - network are pretty much the same [as SDN].
-- Lori MacVittie
You should also follow the link to her article to see the lightheartedly fun sketches that demonstrate some of the high-level similarities between DNS and SDN.