Re: SFPs + Fiber = cost more than switch?
So, the obvious solution if you want to go much further than on-campus will be to use DWDM technology, where 100Gb/s on a single fibre, single wavelength is possible over a 1000km or more, and 200 and 400 can be done the same way up to a couple of 100 km.
I wouldn't be surprised if we didn't see terabit speeds in the long-haul space within a couple of years, although I have no inside knowledge of such developments.
