Per Hansen of Ciena at NANOG 50 talked about growing capacity not by adding more data cables under the sea, rather by increasing spectral density. Eventually new cables will be needed, but meanwhile he thinks we can get up from about 2 bits to to 5 or 6 bits per Hertz. It does require more power: same energy per bit, but more bits.

Plus mesh networks for rerouting, even if it means rerouting backwards around the world, he notes. We’ve observed that sort of emergency backwards routing as long ago as January 2008, in the U.A.E. Cable Cut.

-jsq