Cogent's founder and CEO Dave Schaeffer recently explained the factors that he says differentiate Cogent from other metropolitan Ethernet players in a conversation with Network World's Michael Martin. One reason is there's no standard for any Ethernet speed over one gigabit. It would be inefficient for us to run one gigabit over one wavelength.
Ethernet also suffers from a lot of overhead.
It's not expensive. We use Cisco equipment. We use the 2948 GL3 at the edge and the 12016 at the core. There's about one 12016 in each city. Right now we have 22.