On Tue, 31 Dec 2013, David Hubbard wrote:
My guess would be it's due to existing cable plants. I've worked at a number of places that have tons of multimode fiber run everywhere. If you can re-terminate and re-use, even if inefficiently, it often beats the time and expense required to run new fiber, especially if it's a place that pulling cable may involve trade unions; that gets very expensive to pull what could be a not so expensive cable one or two hundred meters.
Playing devil's avocate here... Compared to the cost difference between, say 40G SR equivalent optics and 40G LR equivalent optics, the cost of pulling, terminating, and testing new SMF between two relatively close points is pretty small. I say that with the following qualifier: If you have usable path (conduit, innerduct, rackspace for new termination bays, etc) in place between points A and B. If it turns into a situation where you need to dig to lay in new conduit, that's a different matter altogether. The problem is markedly worse at 100G. DPO-24 is just evil, but the cost difference between 100G SR10, LR4, and ER4 optics is still ridiculous. jms