What Is Holding Back the Cable-Free Datacenter?

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Servers, switches, and other components can be virtualized and condensed easily these days. But what can't shrink as easily are the thousands of feet of copper and fiber optic cabling that interconnects components together.

When I saw the latest images of Google's massive datacenters around the country, the first thing that caught my eye was the tremendous amount of space that cabling consumes in them. We're talking about miles of copper and glass that can get out of control quickly if not under the watchful eye of a diligent IT administrator. While a single Cat-6 cable isn't much of a problem, try handling thousands of them crisscrossing datacenter racks, ceilings, and floors. Switch virtualization has helped somewhat, but there will always be a need for a way to interconnect multiple systems. And as bandwidth demands increase, physical cabling is our one and only option.

But a new IEEE standard is looking to help eliminate cabling by providing wireless transport that's fast enough for use in the datacenter. 802.11ad operates within the very high-frequency 60GHz range and has the potential to move traffic at up to 7Gbit/s. Combine the impressive speeds with the added benefit of having virtually zero network cabling management, and you have a recipe that will usher the next great leap in datacenter design methodologies. The only problem is, you'll have to completely redesign your current datacenter from scratch.

There is a weighty tradeoff when using 802.11ad that operates at such high frequencies. While the protocol allows for tremendously fast throughput, it does so at the cost of communication distance and obstruction limitations. An 802.11ad wireless signal can only transmit signals 9 or 10 meters at the most if the path between the transmitter and receiver is clear of obstructions. In order to get the best bang for the buck in terms of 802.11ad wireless network communication and fault-tolerance, researchers at Cornell University and Microsoft have developed a next-generation datacenter that is cylindrical.

By going cylindrical, you can take advantage of the full 360-degree range for point-to-point wireless communications. Servers communicate with each other within the circular rack by sending 802.11ad communications in a directional beam from an internally positioned server to a handful of listening servers on the receiving end seated on the outside of the circle. According to the Wired article, "every server is a kind of mini-switch -- called a Y-switch -- and none of the server racks need traditional networking switches for communications." No traditional switches for interconnecting devices also means no traditional cabling.

The idea of wireless communications sounds great, but datacenters designed to house rows of servers contain plenty of 90-degree angles. Along with that, cooling, lighting, and electrical follow rack rows in straight lines. In other words, circular datacenters may eliminate cabling, but they create a whole new problem.

That's why it is so critical to begin to push for datacenter components that are modular and easily moved. Everything from power receptacles to chillers and even internal walls need to be easy to break down and reposition. While you may never have to redesign your datacenter to accommodate circular racks, it doesn't hurt to build-in the flexibility, because you never know what innovation will come next.