Technology

Shedding Light on Dark Fiber for Data Centers

When evaluating your data center connectivity, there are many reasons to consider dark fiber, including cost control, flexibility, security, and scalability. To quickly understanding the basics of fiber optics, see my blog posting, “Tech Primer: Dark Fiber, Lit and Wavelengths.

Importance of Dark Fiber for Data Centers

The number of internet connected devices known as the Internet of Things (IoT) is expected to reach 20+ billion by the year 2020, according to a recent Gartner report.

Gartner report - IoT growth from 2014 - 2020Likewise, cloud usage has been escalating at a similar rate, year over year. The reliance on cloud platforms such as Amazon’s AWS, Microsoft Azure, IBM SoftLayer and Google Cloud also continues to skyrocket, as indicated by cloud revenues seen in this report from Synergy Research Group.

These growth markets are driving enterprises and online businesses to a level of network dependence that is becoming hyper-critical.

Growth of Cloud Providers - Synergy Research Group Report

Connectivity is King

A loss of network connectivity or degraded network performance across a network connection can cause more than the loss of revenue. Poor network performance could even cause the loss of a life in the case of some environments like healthcare, public safety, and the military.

How vital is your network? When stability, along with latency, security, and bandwidth are at the forefront of the decision makers mind, then dark fiber may be the answer.

RagingWire understands that connectivity is of paramount value in a data center. As such, RagingWire has both partnered with connectivity providers and made a significant capital investment in telecommunications infrastructure to service our customer’s unique needs.

For example, in our Sacramento data center campus, we partner with multiple carriers to provide lit and dark fiber services that deliver excellent network performance of ~2ms latency to San Francisco, and ~4ms latency to the South Bay – a location jam-packed with cloud providers.

In our Ashburn, Virginia data center campus, we offer both lit and dark services to multiple carrier hotels and cloud locations, including AWS and Azure, providing sub-millisecond latency between your carrier, your data, and your data center.

In Garland, Texas, within the Dallas-Fort Worth Metroplex, RagingWire has built a fiber network that connects its 1,000,000 square foot of data center campus to over 128 locations in the Dallas and Fort Worth market, including popular carrier hotels and cloud providers.

The Good, the Bad, and the Ugly of Dark Fiber

Dark fiber may be the right decision for many of today’s infrastructure connectivity needs, but make sure you go into it with full awareness of its advantages and disadvantages.

The Good:

  • Cost-control: Dark fiber costs the same whether you intend to use 1Gb, 10Gb, or 100Gb.
  • Flexibility: You may run any protocol and any service. You may even choose to install your own multiplexing equipment and slice the fiber into multiple channels (generally 16 channels, but current off-the-shelf hardware allows for up to 160), each usable for 1Gb, 10Gb, or 100Gb.
  • Security: Public access telecommunications networks generally have multiple access points at various nodes throughout the network, whereas dark fiber routes are accessible only at each of the two endpoints of the fiber run.
  • Scalability: Service may be upgraded as required by simply using higher performance equipment. Available bandwidth on dark fiber is limited by only three things: Physics, current technology, and your budget.

The Bad:

  • Cost-control: When your bandwidth requirements are 1Gb or less, lit services will usually be less expensive than fiber when considering the initial lease of fiber and capital outlay for hardware. Additionally, long-distance dark fiber may be more expensive than purchasing a wavelength. You’ll have to do the math and figure out which meets your needs and budget.

The Ugly:

  • Reliability: Your architect will need to design around the fact that there is no built-in fault-tolerance or connectivity failure protection. This will usually require the purchase of a second diverse dark fiber path between your two locations.
  • Scalability and cost-control: Dark fiber is point-to-point. Unlike many other carrier products available, dark fiber does not allow for multiple end-points on a network. It may be necessary to purchase multiple fiber paths for larger networks.

Summary

When considering dark fiber from fiber providers instead of lit fiber or carrier services from telecom providers, it is beneficial to map your unique IT connectivity needs with the strengths and weaknesses of dark fiber. This mapping exercise should help shed some light on the best connectivity options for your custom environment.

Connectivity Questions

Is your data center carrier neutral? Carrier neutrality is vital when choosing a data center. You want your data center to freely allow interconnectivity between all carriers and other colocation providers. This protects your interests and allows for future scale, plus it maximizes your flexibility.

What types of lit connectivity are available? It is less important to focus on the number of carriers in the campus; instead focus on whether the carriers you care about are available. Also ask if their direct competitors are available. This will be helpful for bidding – to keep your primary carrier as cost competitive as possible.

Is dark fiber available? If so, where does it go? Does the data center have a dark fiber product or a partnership? Where does it go and is the pricing competitive? Does the data center have lit connectivity options or a partnership?

 

Tech Primer: Dark Fiber, Lit and Wavelengths

Some IT colleagues have asked me, “What is dark fiber and what’s the difference between lit and wavelengths?” Let’s begin by understanding the basic concepts of fiber optics and the difference between dark and lit fiber.

Difference between dark fiber and lit fiber

Unlike wire, which passes electricity through a metal conductor, fiber optic cables use a specialized glass or plastic allowing for data to be transmitted great distances by passing light through the glass. Fiber that isn't currently being used and has no light passing through it is called dark fiber.

Utilizing this fiber, telecommunications carriers can provide something called “wavelength” services, also known as “waves.” This works by splitting the light into various wavelength groups called colors or “lambdas”. Carriers sell these wavelengths to separate customers and then recombine the colors and transmit it across fiber. Therefore, lit fiber is fiber that has been lit with light by a carrier.

Dark and lit fiber explainedTo better understand lit fiber’s wavelengths, think of a rainbow where each color is a channel of light. Remember Mr. "ROY G. BIV" from middle school – Red, Orange, Yellow, Green, Blue, Indigo, and Violet?

Wavelengths essentially split a single fiber into channels. Unlike copper wire, which uses an electrical signal, fiber optic communications utilize either a LASER or a LED operating at a very high frequency. Fiber optic cables have the ability to carry much higher frequencies than copper cables. Traditional bandwidth throughput (1Gb/10Gb/40Gb/100Gb) will easily fit into a single color channel. Each fiber can be split into hundreds of colors, but a typical lit fiber is split into sixteen colors or lambdas.

The business of fiber optics

In the late 1990's, there was an uptick in the number of carriers building out dark fiber networks. In addition, there was a high degree of inter-carrier trades – a practice where carriers would swap dark fiber assets with other carriers in order to gain a foothold in markets where they were not present or had limited capacity. Inter-carrier trades coupled with mergers and acquisitions allowed even the smallest of carriers to offer competitive data transport agreements around the world.

However, a significant portion of this built capacity remained untapped for years. Carriers wanted to avoid potential long-term lost telecommunications revenues and were reluctant to enable competitors in their high margin wavelength services market. In addition, carriers did not want to cannibalize their often oversubscribed and lucrative Ethernet services market with inexpensive high-capacity fiber. For these reasons, many carriers today still do not sell dedicated fiber assets directly to customers.

New demand for bandwidth

Technology needs have changed over time. Enterprises have become more dependent upon cloud services, interconnected infrastructures have grown in number, and a massive growth in the Internet of Things (IoT) all require a large data communications infrastructure that can scale rapidly, predictably, and on demand.

To fulfill these needs, dark fiber providers have entered the market and are working to provide massive bandwidth, low latency, and high quality connectivity to the end customer in the form of raw glass: dark fiber.

For additional information on the pros and cons of dark fiber versus lit services from carriers, read my blog post titled, “Shedding Light on Dark Fiber for Data Centers.”

White Paper and Webinar from Data Center Knowledge: “Strategic, Financial, and Technical Considerations for Wholesale Colocation”

One of the more interesting developments in the data center industry over the last few years has been the emergence of the wholesale data center market.

Think of wholesale data centers in the context of the traditional retail data center market. Wholesale data centers offer dedicated, multi-megawatt deployments spread out over large footprints of multiple thousands of square feet. These deployments are configured as secured vaults, private suites and cages, and entire buildings.

In fact, RagingWire has made a strategic shift into wholesale data center solutions as was reported in Data Center Knowledge in the article, “RagingWire Pursuing Cloud Providers with New Focus on Wholesale.”

White Paper - Strategic Considerations for Wholesale Data Center BuyersWhile RagingWire has been a leader in wholesale data center solutions, we have not seen very much substantive analysis published on the wholesale space. So we decided to underwrite a research project with Data Center Knowledge to study wholesale colocation and publish a white paper and webinar entitled, “Strategic, Financial, and Technical Considerations for Wholesale Colocation.” Both the white paper and webinar are available free of charge.

You can watch/listen to the webinar by clicking here.

You can download the white paper by clicking here.

What will you learn from the white paper and webinar?

From a strategic perspective, there are a number of new applications, such as video, social media, mobile, big data, and content that are leading to new computing paradigms where the design, scale, and location of data centers become increasingly important.

The financial considerations point out how sales tax abatement, scale economics, and targeting top data center markets as part of your data center portfolio can be advantageous with wholesale data centers. For example, one customer of ours said that for every dollar they spend on colocation they spend $10 on computing equipment. Say you are spending $1 million on wholesale colocation leading to $10 million in equipment purchases. At 5% sales tax, that’s a savings of $500,000.  And equipment is often refreshed every 3-5 years!

Finally, the section on technical considerations studies power density, energy efficiency, PUE and ASHRAE standards, DCIM (Data Center Infrastructure Management), and maintenance. Each of these technical elements can have a significant impact on the performance/cost of your wholesale data center, and ultimately on your business.

RagingWire is proud to support this important research and pleased to share it with the industry.

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