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A Guide to Dark Fiber Networks


Bandwidth requirements are increasing as more enterprises adopt technologies like 5G, automation, cloud, and artificial intelligence to scale and innovate. To properly support technology adoption and a transition to the cloud for your business, you need the right network infrastructure. Dark fiber provides you with control over your network plus scalability, reliability, and cost savings compared to other options.

So, what is dark fiber? The dark fiber meaning refers to fiber optic cables that are unused or “unlit.” This means that these cables are waiting to be leased out to companies or organizations that need a network solution.

Fiber can carry large amounts of data at high speeds, over long distances without interference. This provides great opportunities for those looking to digitally transform.

If your business requires a private connection and has the resources to operate and maintain it, leasing a dark fiber network is the perfect solution for you.

Here are Zayo’s Top 5 key facts on dark fiber that could help you make your decision for connectivity:

1. Dark Fiber Offers Virtually Unlimited Scale

Wherever you are in your digital transformation journey, you’ll need bandwidth to scale now and in the future. This is where dark fiber comes in. Dark fiber gives you what you need now and allows you to expand your bandwidth as your business grows. Once a company has dark fiber, a simple equipment upgrade will allow an immediate boost to network capacity and speed.

Zayo fiber is designed to scale. Zayo Dark Fiber is broad, deep, and highly resilient. This means that you can turn up bandwidth in real-time without needing to order another circuit from a carrier. Our massive, high-capacity network means we have spec inventory available, allowing you to quickly scale as needed.

2. It Enables Seamless Data Transmission

With over 12 billion Internet-connected devices active today and growing, companies have access to more data now than ever before. Today’s organizations rely on data collection and interpretation to run their businesses optimally and provide the best customer experience.

A lot of the new and emerging technologies today rely on fast, reliable data transmission to work optimally. For example, autonomous vehicles rely on extremely low latency connections to make fast decisions to avoid obstacles on the road.

Luckily, dark fiber provides the low latency backbone to support seamless data transmission from edge to cloud, edge to core, and edge to edge. This allows machines to communicate important information immediately for quick decision-making.

3. Dark Fiber is Reliable, Resilient, & High-Performing

Every minute that your company is offline can cost you money, manpower, and resources. That’s why it’s important to leverage a reliable network to decrease downtime and increase performance.

When you tap into dark fiber, you’re leasing it for exclusive use. This means that your connection and bandwidth aren’t shared with other users.

Dark fiber also offers the security needed to send confidential data to stakeholders. Cyber attacks are on the rise and businesses are concerned with the safety of their data.

Luckily, dark fiber provides a high level of security and control by allowing the customer a dedicated point-to-point fiber over a defined physical path. This means that only the customer has visibility into their data on the network. Plus, Zayo’s Long Haul Dark Fiber is mostly underground, which lowers the chances of costly accidents and increases performance.

4. The Difference Between Metro Dark Fiber and Long Haul Dark Fiber

Dark fiber can be split into two major categories, metro and long haul. Metro dark fiber spreads over dense, high-traffic locations within cities to bring fiber to your business’s doorstep. Conversely, long-haul dark fiber connects key markets through Points of Presence (PoPs) using routes that can span thousands of miles. Most businesses require a combination of metro dark fiber and long-haul dark fiber. This allows dark fiber networks to connect to markets and meet customer needs wherever they are.

Additionally, metro and long haul dark fiber differ in their construction. Metro dark fiber is generally installed with higher fiber count cables compared to long haul installations. This allows for more overall bandwidth potential since there are more fibers allowing more data to flow through.  Because metro networks cover a larger area within a city, it allows for more unique and diverse routing options compared to the single point to point option of a long haul route.

On the other hand, long-haul dark fiber is mainly constructed of single-mode fibers. These fibers have smaller glass cores and only allow for one mode of light transmission. Single-mode fiber limits the amount of data you can transmit at one time. However, there are no significant distance limitations, which makes it great for spanning long distances.

5. Dark Fiber Allows Greater Control Over Your Network

Dark fiber provides all the security, scalability, and reliability of a private network, without the burden of owning your network infrastructure.

One of the downsides of working with Internet providers is that you’re at the mercy of their limitations, pricing, and schedule. To expand your bandwidth, you need to order more wavelengths and wait for the provider to fulfill the request.

By leasing dark fiber, you can manage and operate your network yourself without your provider getting in the way. Once you install your equipment, you have complete control over your private, dedicated fiber network.

As your bandwidth requirements increase, you can add capacity by installing a new card in your existing equipment. Zayo gives you the autonomy to scale your network securely and reliably.

Tap Into North America’s Largest Independently Owned Fiber Network

Zayo is proud to be a market-leading fiber-optic network provider. Our team has developed more fiber capacity in the past decade than anyone else in the industry. By taking advantage of Zayo’s extensive Dark Fiber network, you leverage the benefits listed above plus:

  • Unique, diverse Metro Dark Fiber and Long-Haul Dark Fiber routes connecting major markets across the United States and beyond
  • 400G capabilities across the Dark Fiber backbone
  • Performance guarantees based on customer loss budget requirements and backed by our SLAs
  • Flexible configuration choices with point-to-point, hub-and-spoke, and ring network configurations
  • Outage protection with 15 million miles of fiber, offering diverse routing
  • Geographic reach in major metro markets and long-haul routes

Explore Zayo’s diverse Dark Fiber network footprint here.