You’ve made up your mind that a fiber optic connection to your business is no longer a luxury. It is essential to productivity. Now the question is which type of fiber to order. What? There is more than one type of fiber?
One Strand, Multiple OptionsAll fiber optic connections are based on the principle that modulated light waves carry information guided through a glass strand. The fiber cable coming into your building will look the same. What changes is how you terminate it.
Basically, there are three fiber options. You can order lit fiber service, dark fiber, and wavelength service. Which you pick depends on your bandwidth, security, and control requirements. Let’s see how the three compare.
Lit Fiber Bandwidth
Lit fiber bandwidth is what we normally think of when we’re talking about fiber optic service. You are leasing a service that provides a certain amount of bandwidth, usually with guarantees as to the latency, jitter, packet loss and availability.
How this is done is handled by the service provider. They will terminate a fiber strand into customer premises equipment at your location. You connect your network via fiber or copper connection, depending on the bandwidth level.
Early fiber optic implementations were based on the SONET optical carrier system and needed a specially designed interface for each service level. Today, most fiber service uses Carrier Ethernet and is good for any bandwidth up to the speed of the port that you have installed. Most companies opt for Gigabit or 10 Gigabit Ethernet, although you can often specify up to 100 Gbps in major metro areas.
You pay based on the speed of service you request. One nice feature of Carrier Ethernet or Ethernet over Fiber, as it is also called, is that the bandwidth is easily adjusted. You can install a Gigabit port and order and pay for 100 Mbps service if that’s all you need. When activity picks up, you can easily increase the bandwidth with a phone call or even online portal. Your service bandwidth will change, as will your monthly bill.
Wavelength Fiber Service
While in-house fiber optic networks might use a single laser beam to transmit data, outside carriers that run large networks use a combination of multiple strands of fiber within a single bundle and multiple wavelengths within each strand. This is a more efficient use of expensive fiber cabling and the only real way to accommodate all the traffic on the regional, national or international network.
The process of using multiple lasers, each tuned to a different frequency or wavelength is called multiplexing. All the beams exist at the same time but since they are different colors, they don’t interfere. You can imagine it something like a rainbow, although the frequencies tend to be in the infrared rather than visible band. Each separate wavelength, also called a lambda, can act like an independent fiber optic strand, although virtually. The physical strand carries them all.
There may be dozens or hundreds of different wavelengths on the same fiber strand depending on whether Coarse Wavelength Division Multiplexing (CWDM) or Dense Wavelength Division Multiplexing (DWDM) is used. Each of these wavelengths can carry lit fiber optic service or it can be leased to one customer.
When you order a wavelength, you do so because you need high bandwidth such as 10 Gbps. You also want the ability to use whatever protocol you like or multiple protocols over the same wavelength using your own multiplexing. You’ll typically provide the termination equipment that determines all this, although you might be able to lease it from the service provider. Another advantage of wavelength service is that security is improved because only your traffic uses that particular wavelength and there is no sharing of traffic between wavelengths.
Dark Fiber Service
The ultimate in control comes from having your own fiber optic network or the next best thing, a private fiber strand on your service provider’s network. This private strand is called dark fiber.
Most every Wide Area Network contains unlit fiber strands that are intended for future service expansion as traffic levels increase. It is very expensive to install fiber in trenches or on poles over long distances. The incremental cost of have more strands in the fiber bundle is usually well worth the extra expense compared to having to add more fiber cable later. Some cables have 100 or more fiber strands.
Many fiber network carriers are quite willing to lease out some of these unlit strands as long as there is plenty of capacity left for them to expand. The advantage to you is that dark fiber gives you control of the amount of bandwidth you send down the fiber, the protocols you use, and the best security you can have over long distances unless you install your own fiber cable from point to point. Once again, you provide the termination equipment at each end of the fiber run. In some cases, you can lease this from the service provider.
So, which type of fiber optic service is right for your business? Most of the time regular lit fiber bandwidth will get the job done. In special cases, wavelength service or dark fiber may be the solution. Compare options and see how much bandwidth is readily available at affordable prices for your business location.
