Usually we expect available bandwidth to top out at 5 or 10 Gbps. Sometimes carriers can support 40 Gbps on their networks while they move up to 100 Gbps themselves. Now, one competitive carrier is setting a new benchmark at 400 Gbps.Integra Telecom is one of the country’s leading providers of fiber optic networking solutions. They own and operate a long-haul fiber network that stretches for 5,000 route miles. This is expanded by 3,000 miles of metropolitan fiber connecting more than 2,200 enterprise buildings and data centers.
This describes only the lit and operational fiber assets provided by Integra. Among their 160,000 miles of fiber assets are dark fiber pairs just waiting to be pressed into service. If your requirements go beyond the usual WAN requirements, dark fiber may be the answer to your high bandwidth needs.
What is dark fiber? It is essentially fiber optic strands in a fiber bundle that are not in use. Fiber itself is cheap compared to the cost of burying it in the ground. That’s why anyone installing fiber cables over any distance makes sure that there are many, many extra fiber strands beyond those they expect to use. If you install too small a cable and see your traffic grow in the future, it gets very expensive to duplicate your network by installing more fiber. Since fiber strands are about the size of thick hairs, why not install a cable that has 100 or more pair even if you are planning to light only a dozen?
Integra has lots of fiber beyond their immediate or expected needs. Rather than let all of that unused capacity sit idle, they are offering it to large enterprises, healthcare organizations, governmental agencies and educational institutions that can put it to good use. Their options include bundles, lease and Indefeasible Rights of Use (IRU) that offer complete fiber pairs dedicated to your exclusive use.
Why would you choose to use dark fiber instead of other bandwidth services? Bandwidth is certainly a driver. A single pair of dark fiber supports up to 400 Gbps of lit transport. A pair is used to provide protection against failure in a single fiber or the equipment it connects.
How is it possible to get this much bandwidth from one fiber pair? It has to do with how you transmit your data. The glass fiber itself has nearly unlimited bandwidth, at least for any applications we can envision now. The inefficient way to transport data is to feed one end of the fiber with a laser of a certain color and modulate that beam with your data. Sure, you could get 5 Gbps or more using this technique. You certainly won’t get 400 Gbps. For that massive capacity you need to use the fiber more efficiently.
Right now, the go-to technology for increasing fiber capacity is called DWDM or Dense Wavelength Division Multiplexing. Instead of sending one beam down the fiber core, you send dozens or even a hundred or more beams simultaneously. Each is a different wavelength or color called a Lambda. You split up your data stream at the sending end and recombine it at the receiving end.
Of course, you can treat each wavelength as a separate and individual transmission path. This is most often how DWDM systems are set up. Each channel is a high bandwidth communications link completely independent of the others. There is no requirement that the channels use the same protocol or run at the same speed.
Another big advantage of dark fiber is network security. You and you alone have use of the fiber strands. There are no other customer’s signals multiplexed with yours as they generally are on the usual data services. This can be especially advantageous for companies with very high security requirements, such as banks and governmental agencies.
You should also know that there is another step between fiber optic bandwidth services and dark fiber. This involves leasing a complete wavelength on a lit fiber link. You have the security of being the only traffic on that wavelength and avoid the cost of buying and operating your own terminal equipment.
Are your bandwidth needs well beyond the services that are being offered commercially? Dark fiber pairs may be the solution to your demanding requirements. It’s readily available in many business locations.
Note: Picture of glowing fiber optic strands courtesy of Wikimedia Commons.
