Free and nearly infinite bandwidth sounds like a futurists dream, but its almost the present-day reality of dark fiber—vast numbers of fiber-optic channels in the ground but as yet unlit by lasers and network protocol encoders.
Combined with the plummeting price and improving interoperability of midtier CWDM (Coarse Wavelength Division Multiplexing) hardware, dark fiber is a resource that offers high return on investment to the enterprise IT professional whos willing to explore new ways of buying and managing network capacity.
The supply of fiber-optic bandwidth thats already installed, in a surprising variety of places, vastly exceeds demand at current prices. Industry estimates suggest, for example, that roughly seven-eighths of the city-to-city fiber in the United States and Europe has never been equipped with networking hardware at its endpoints. When supply exceeds demand, prices fall—but only when potential buyers recognize that this situation exists and when sellers accept the need to adjust their expectations.
Gary Gunnerson, IT architect at USA Today publisher Gannett Company Inc. and an eWEEK Corporate Partner, gave eWEEK Labs an inside look at his companys emerging dark-fiber strategy. Gunnersons explorations of emerging network hardware standards and vendor offerings—and his research into more effective ways of matching buyers and sellers of both raw bandwidth and managed services—suggest that momentum is the only missing ingredient for a richer mix of cost-effective communication.
Not only is there a lot of fiber in the ground, said Gunnerson, but the fiber is also becoming steadily cheaper to exploit using CWDM hardware.
CWDM places a relatively small number of channels on a fiber pair—typically four to eight, compared with the tighter spectral packing (that is, more nearly similar colors of light) of DWDM (“D” for dense) technology. DWDM uses 16 to 64 colors per pair.
When fiber pairs are scarce, the tighter tolerances of DWDMs cheek-to-cheek channel packing are cost-effective. However, todays abundance of glass in the ground shifts the balance in favor of endpoint simplicity, especially since few sites exceed the capacity of eight-channel CWDM on a single fiber pair.
CWDM costs are being further pushed down, Gunnerson said, by the late-2003 standardization of CWDM wavelengths. These wavelength agreements give Gunnerson and other buyers greater confidence in the interoperability of CWDM and DWDM hardware on a single cable plant.
That mixed-signal freedom makes CWDM a more attractive entry point for enterprises that envision future growth in their bandwidth needs. It also makes CWDM an option for incremental expansion of established installations.
When its increasingly easy and cost-effective to place many data channels on a single strand of glass, it might seem unlikely that anyone would put any more fiber capacity in the ground than they can readily sell. But, said Gunnerson, fiber glut has been the natural result of installation economics that almost compel laying orders of magnitude more fiber than will be needed.
“Bundle counts vary,” Gunnerson said, adding that its typical to get more than 250 pairs of fiber in a 1-inch bundle—with four bundles typically installed in a single right of way. “There might be over 1,000 pair for one company trenching down your street in front of your building, and you need only one pair,” Gunnerson said. “Multiply that by two or three companies, and you see there is a lot of excess capacity.”
In this market, Gunnerson said, it may well make sense for an enterprise IT department to build its own metropolitan area network, including telecommunications circuits. Companies can lease fiber, install network equipment and pay for raw capacity at wholesale prices instead of buying network circuits at retail.
What sends the price of bandwidth not merely into a dive but into a veritable tailspin is the amount of fiber thats in the hands of owners other than the usual suspects—that is, other than telecommunications companies with their long experience in traditional pricing practices.
“There are many companies that have rights of way, such as gas pipelines, power lines, train tracks, sewer systems, cable companies, water companies—you name it,” said Gunnerson. “Many have placed optical cable along those pathways.”
Gunnerson added that bandwidth may well be found in unlikely locations. For example, he said he discovered that “a small, 10-square-mile beach town in North Carolina has three optical providers trenched along the single main road, supporting an off-vacation peak population [of] less than 10,000 people.”
In short, that underground excess can surface almost anywhere. But you have to find it first: “The discovery process to uncover owners and pathways of existing optical fiber takes some time,” said Gunnerson, who added that some kind of dark-fiber clearinghouse “would make our job much easier.”
Gunnerson envisions several ways that enterprises and other user organizations can improve their access to those resources. “A Web site dedicated to fiber trading partners … could take our office and carrier hotel addresses and spit out cable providers, distances and possible installation costs.”
Gunnerson uses the common nickname of carrier hotel (sometimes called a co-location center or colo) to denote a site where multiple carriers endpoints create an array of competing options for customers and where that proximity also lowers costs. “At the hotel, it is less expensive for [carriers] to connect to you and you to them, as youre both in the same building,” he said. Provisioning time and costs to connect are much less, he added, than for the typical local-loop facilities that connect a traditional central-office installation for a single carrier to a customers location.
A key question is whether the kind of excess fiber that a carrier installed yesterday will meet enterprise needs tomorrow. On this point, Gunnerson was unhesitatingly confident: “Some studies have shown that the long-term viability of fiber is excellent, with the aging fibers actually getting stronger over time. Fiber itself can last multiple tens of years.”
Those in search of cost-effective capacity should keep this in mind, Gunnerson said, because “five- and 10-year fiber leases are quite expensive, with [attractive returns] not arriving until longer, 15-year terms are embraced.”
Gunnerson also urged his IT peers to think creatively about what it is that theyre leasing when they sign an agreement to use in-place fiber bandwidth. The lease need not be tied to a specific route if the lessor also has capacity throughout a region where the lessee has possible future interests.
“Changing locations and adding locations are certainly actions that should be contemplated and covered in any dark-fiber lease,” Gunnerson said, adding that there should also be clauses that deal with the possibility that a future location might not fall near existing fiber. “Adding buildings not located on or near fiber-optic assets costs a lot of money in fiber construction, [but] there may be other means to include a specific office in a dark-fiber network, such as a point-to-point optical circuit or other bypass technologies,” he said.
Potential buyers will benefit from having a simple means of identifying installations that might benefit from dark-fiber leasing, said Gunnerson. “The rough rule of thumb weve been using for examining potential savings by using dark fiber, xWDM and carrier hotels is a monthly expense of $7,000 for all voice, data and Internet connections. We see that expense as a rough break-even point for dark fiber,” he said.
Gunnerson added that savings are derived “from creating a fixed price for all local-loop fees with the fiber lease, and competitively bidding voice and data services at the carrier hotel.”
In other words, the company buys its local bandwidth in bulk. It then ships all its bits—whether they represent data, voice or more exotic forms of content—to a nearby open market, where content-specific service providers can bid for the business of sending them on their way. If these different kinds of traffic are still under different jurisdictions within a company, this may be the impetus thats needed to consolidate those responsibilities for maximum bulk-buy advantage.
When bandwidth prices fall so far and so quickly, formerly extravagant use of bandwidth may now become cost-effective. For example, said Gunnerson, business continuity is a higher priority in the post-9/11 environment, and plummeting bandwidth costs enable much more capable continuity arrangements involving database replication and remotely located failover facilities.
Seizing these advantages may require IT departments to make small but vital additions to their maintenance skills and hardware.
“The most important thing to learn is that fiber within an xWDM network must be pristinely clean,” Gunnerson explained. “All cables must be cleaned thoroughly and examined under a 50x microscope. Dirty fibers cost you in reduced optical power levels. Even taking a fiber patch cable out of the patch bay and reinserting it can add dirt that reduces power levels.”
Gunnerson was quick to reassure his colleagues, however, that more exotic skills and equipment will rarely be needed. “Knowing how to use an [OTDR] optical time domain reflectometer and an [OSA] optical spectrum analyzer would be a bonus,” he said, “but these skills are required only at the initial stages of installing an xWDM solution.” In addition, these skills are now part of network technician certification programs offered by many institutions, including vendors of that test equipment.
“The xWDM equipment installer should be expected to have and understand both OTDR and OSA gear,” said Gunnerson. “Otherwise, xWDM networking equipment is easier to understand than most routers and switches.”
The substantial long-run savings of dark-fiber leasing will be obvious and immediate, Gunnerson said, adding that a company can expect to pay a premium if it hires someone else to manage things. “We found that managed dark-fiber solutions typically cost 300 to 400 percent more than our identified costs,” he said, adding that “after understanding those costs, we were encouraged to roll our own xWDM networks.”
Making or breaking those economics, he continued, will depend on understanding the keys to ease of management and continued competitive cost reduction.
“Two items we required were remote management capability and exposing the optical receive power through the management interface,” he said. “Without intelligence monitoring the receive power levels, youd need to buy a spectrum analyzer and send people out on a regular basis to check the health of the optical network. We also liked products that used the small-form-factor pluggable lasers, as they open up the opportunity to use multiple suppliers.”
Gunnerson compared the cost of owning a fiber plant to the cost of laying a railroad line. “Its a long-range fixed cost,” he said. “Once the rails are laid, any number of devices can ride the rails. Once the fiber loop is created, almost any kind of optical device can light the fiber.”
Technology Editor Peter Coffee can be reached at [email protected]davis.com.
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- ColoTraq offers prospective bandwidth buyers a portal into the world of carrier hotels, dark-fiber resources and managed services
- An Illinois city revives a ring of not merely dark, but also almost forgotten, fiber as a foundation for improved business competitiveness
- A Highbeam Research paper, available to members or free-trial subscribers, warns that simple dark-fiber leasing isnt always superior to purchase of managed services
- The International Telecommunication Union publishes a compact summary describing CWDM fundamentals and standards
- Atcom Inc.s LANshack.com site offers a tutorial on fiber-optic testing techniques and equipment
- NetPlane Systems looks at opportunities for improved network control on end-to-end optical connections