Upgrading from copper to fiber optics is a significant step for many businesses, but for some, it’s simply not enough. When even the highest capacity fiber optic services lack the necessary bandwidth or security features, dark fiber emerges as the solution.

One might wonder how lit fiber services could be insufficient, considering they offer speeds up to 10,000 Mbps (10 Gigabit SONET or Ethernet) and, in some cases, even up to 40 Gbps (OC-768). Additionally, carriers are upgrading their backbone networks to 100 Gbps.

While this is true, certain organizations require even greater bandwidth, control, and security. These requirements can be met by controlling the fiber itself, rather than relying on a service shared by multiple paying customers.

This is where dark fiber comes in. Dark fiber refers to fiber optic cable that has been installed but is not currently in use. It earned its name because it hasn’t been “lit” with laser light. A significant fiber optic cable buildout in the late 1990s resulted in a surplus when the anticipated internet boom faltered.

Some of this surplus fiber is still available for lease, although much of it has been acquired. Consequently, more dark fiber is being installed to meet the increasing demand for business bandwidth. This demand is driven by advancements in big data, healthcare automation, cloud computing, and other technologies. There is a growing need for interconnection, larger data files, and faster transmission speeds.

Organizations handling large volumes of data, such as carriers, financial institutions, research labs, and video production companies, may find leasing dark fiber beneficial for connecting locations within a city or across cities. Several large network operators, including Zayo, offer dark fiber assets for lease in various cities.

For on-campus connections, installing your own fiber optic cable might be feasible. However, connecting locations over longer distances requires leasing fiber from specialized companies. These companies invest in laying multiple cables containing numerous fiber strands along permitted routes. Typically, one or two strands within a cable are leased, granting exclusive use for the lease duration. Lessees are responsible for installing equipment at both ends of the fiber run to transmit their data.

Dense Wavelength Division Multiplexing (DWDM) is a technology that enables the transmission of massive data volumes. It involves sending multiple laser beams at slightly different wavelengths (colors) through a single fiber. Each beam operates independently, carrying data at speeds ranging from 1 Gbps to 10 Gbps. DWDM can generate over 100 individual wavelengths, each capable of transporting any desired protocol independently.

Dark fiber’s security advantage stems from having complete control over the fiber strand. Only your equipment is connected, eliminating access points for potential intruders to intercept data. For enhanced security, encrypting data packets during transmission over the fiber is an option.

Transitioning from traditional SONET or Ethernet over Fiber to Dark Fiber doesn’t have to be an all-or-nothing approach. Leasing one or more wavelengths or opting for a managed fiber solution, where the provider installs and manages the termination equipment, are viable options.

If your organization has bandwidth requirements that exceed the capabilities of common solutions, explore the availability of dark fiber assets and managed fiber services for your desired locations.

Note: Photo of fiber optic conduit spools courtesy of Wikimedia Commons.