In modern times, the term “dark Fiber” is now used to discuss the ever-growing, standard procedure of leasing out Fiber optic cables from a network provider/service provider, or, out to the Fiber installation/Fiber infrastructure that isn’t owned by regular carriers. Dark Fiber can still be called “dark”, even if it has been utilized by a Fiber lessee and not by the original owner of the cable.
When Fiber optic cables are installed, many companies will actually overestimate the total amount of supplies and cables needed in order to perform the job. The reason for this is so that the company has the ability to somewhat prevent their dark Fiber network from procuring a huge overgrowth of data. Because of this, and due to advances in data-packaging, optical Fiber networks have extraneous space that is being unused. As a direct result, a dark Fiber network then has the opportunity to take advantage of this extra space.