In the data center environment, people have been talking about migration plans for a long time. It is an important subject. Because of the growth of services and the increased bandwidth demanded by each of those services, many data centers need to be upgraded every 3-5 years. Planning and implementing an upgrade is a bit like a balancing act. Upgrades are expensive, but at the same time, you need to be sure that you’re installing an infrastructure that will support the next generation of equipment. To do this in the most effective and efficient way possible, living within your budget is key.
There is more than one type of budget to consider. There is always a financial budget to keep in mind. We would all like to have “the best” system/product/solution, but financial realities demand that we carefully examine what we need, prioritize our requirements, and choose the solutions that will deliver the best return on investment.
If we just look at cabling as an independent component, there are several variables that contribute to cost. For example, traditional cable plants have been designed with OM3 multimode fiber. Going to OM4 –or OM4+ – is more of an investment, but the added bandwidth gained may be needed in order to overcome insertion loss. Single-mode is the least expensive cable, but as a solution, single-mode can be up to three times more expensive than multimode. Connectivity costs can be higher, and the cost of optics is definitely higher with single-mode. Speaking of connectivity, the use of MPO trunks and cassettes is more expensive than directly terminating with LC connections, but with LC connections, you lose the flexibility to support parallel optics.
Financials are important, but they are not the only budget you need to consider when planning a migration path. The link budget is also important. Saving money on a system that does not work will not actually save any money at all. Therefore, it’s important to understand whether or not your cabling will support your protocol.
In theory this is simple. Your system either works or it doesn’t, right? Not exactly. With the number of PMD options constantly increasing, it can be difficult to keep track of all of the variables. A PMD is the Physical Media Dependent form factor for the transceiver connection. Each PMD has a set of conditions that are needed in order for it to operate correctly. These conditions include the fiber type, connector type, bandwidth support and cabling insertion loss.
IEEE defines worst case conditions to ensure interoperability, but these limits can be very restrictive. Consequently, it is very common for users to take advantage of an engineered link to produce better performance. An engineered link is one where one or more performance attributes are specified to be better than the standard. This enhanced performance can be achieved with higher bandwidth fiber, lower loss connectivity and/or better performing transmitters and receivers. With the number of potential options available, the number of possible solutions seems infinite.
So how do you go about determining the best migration plan – one that balances your budget considerations with your desired network performance objectives?
One approach is to install a minimally compliant cabling architecture. This allows your purchasing department to use a bidding process for commoditized components. This approach can save a significant amount of money when the data center is initially being built. But when the time comes to upgrade the IT hardware, there is a significant risk that the cabling will also have to be replaced. This is also an important consideration when the network is being built in pieces, with the involvement of more than one department. Decisions made by one department, with the desired intent to save money, forces the next department to spend more in order to keep it working.
Another approach that is commonly discussed is to install single-mode. This medium has significant bandwidth availability to allow for several generations of growth, or what is sometimes perceived as being “future-proof”. However, it’s important to remember that, with new varieties of transceivers arriving on a regular basis, you still need a plan to deal with changing connector styles and data rates.
At the beginning of 2016, Berk-Tek introduced a program called “Own the Link.” The main concept behind the program is that the performance and cost of the cabling and transceivers are inextricably linked. You cannot alter the specification of one of these components without having an impact on the other. The experts in The TEK Center at Berk-Tek understand how these components work together. Using expertise gained from years of network performance testing, they have created models that allow the user to determine the best fiber and transceiver selection. With this knowledge, they developed a tool, known as the Power Budget Calculator, a powerful predictor of link performance. It allows the user to know, with confidence, if the cabling design will support a future network protocol.
This answers the question of “Will it work?” But what about the other half of the equation; the question of cost?
A holistic tool is needed that can look at all of these variables and arrive at the most cost effective solution. What are the physical constraints of my design? What data rates are needed today and in the near future? What are the limitations of the various fiber options? What do they cost? By taking into account a complete cabling system and the transceivers, we can arrive at a cost model that helps answer the fundamental question, “What is the best migration plan?” Berk-Tek’s Own the Link Cost Calculator is that tool.
This easy-to-use calculator tool works by first asking a couple of simple questions:
- What is the distance between your active devices?
- How many cabling segments are needed to connect the devices? (In other words, are there connection points needed between the switches.)
Based on these two pieces of information, the tool calculates the amount of bandwidth and insertion loss encountered by a TIA-compliant cabling link. This is done for OM3, OM4, OM4+ and single-mode fibers, then matches up each with the PMD options currently available in the marketplace. The calculator then calls on the proven modeling developed by the TEK Center to analyze each option and eliminate any of the solutions that will not work. For the remaining options (those that will work), a budgetary financial cost is established for the complete cost of the link, based on all of the fibers, connectivity and transceivers used for the connection. The tool automatically selects the lowest cost option and reports it back to the user.
In parallel, the tool looks at an engineered link option. Using the same set of criteria as discussed above, it determines the lowest cost working solution. The cost of the engineered link is then shown alongside the cost of the standard link. The cost savings of an engineered link versus a standard link can be astounding. Seeing these options side-by-side gives the user critical information to inform their decision. By combining the link calculations of the power budget with the cost variables of the cabling options, the Own the Link Cost Calculator reduces the myriad number of options to a single solution – the lowest cost option for the desired migration.
About Berk-Tek
For more than 50 years, Berk-Tek has been a leading manufacturer of more than 100 different network copper and fiber optic cable products. The company has led in the development of high-performance and enhanced fiber optic and UTP cables designed to transport high-speed data and voice transmissions. Berk-Tek has manufacturing facilities at New Holland, PA, and Fuquay-Varina, NC. For more information, visit www.berktek.com.