Application Notes 24-Fiber Trunking and Interconnect Solution The Right Migration Path to 40/100 Gig For more information, visit commscope.com What the Standards Say Video views on YouTube climbed from 100 million views per day in 2006 to well over 4 billion views per day in 2012. Song downloads on iTunes increased from 5 billion in 2008 to more than 16 billion by 2012. Average smartphone usage tripled in 2011*, and forecasts estimate that by the end of 2012, the number of mobile-connected devices will exceed the number of people on earth. Over the next two years, our world will create, process and store more data than in the entire history of humankind. In 2002, the IEEE ratified the 802.3ae standard for 10 GbE over fiber using duplex fiber links and vertical cavity surface emitting laser (VCSEL) transceivers. Most 10 GbE applications use duplex LC style connectors where one fiber transmits and the other receives. Standards efforts aimed at finding a cost-effective method to support next-generation speeds of 40 and 100 Gbps, and in 2010, the IEEE ratified the 802.3ba standard for 40 and 100 GbE. Similar to how transportation highways are scaled to support increased traffic with multiple lanes at the same speed, the 40 and 100 GbE standards use parallel optics, or multiple lanes of fiber transmitting at the same speed. Running 40 GbE requires 8 fibers, with 4 fibers each transmitting at 10 Gbps and 4 fibers each receiving at 10 Gbps. Running 100 GbE requires a total of 20 fibers, with 10 transmitting at 10 Gbps and 10 receiving at 10 Gbps. Both scenarios call for using high-density multi-fiber MPO style connectors. In conjunction with the media demands of today’s Internet and the mobile network boom, the amount of data transmitted at the enterprise business level is also rapidly climbing as networks need to support more devices and advanced applications than ever before. Cisco Visual Networking Index* forecasts that business data traffic will grow 22% between 2011 and 2016, with business video conferencing alone increasing sixfold. In fact, it is estimated that by 2016, the gigabyte equivalent of all the movies ever made will cross global IP-based networks every three minutes, with North America accounting for 3.3 exabytes per month, or more than 3 billion gigabytes. Data centers are at the heart of the tremendous amount of business data needing to be transmitted, processed and stored. In the data center, fiber optic links are vital for providing the bandwidth and speed needed to transmit huge amounts of data to and from a large number of sources. More bandwidth is also needed to support the use of virtualization that consolidates multiple computer platforms onto single physical servers to reduce the amount of equipment and improve space utilization. As data center managers strive to provide the bandwidth they need, transmission speeds at core switches are increasing and backbone infrastructures are experiencing a significant upsurge in the amount of fiber optic cabling. Typical transmission speeds in the data center are beginning to increase beyond 10 gigabit per second (Gbps). In 2010, the IEEE ratified the 40 and 100 gigabit Ethernet (GbE) standard, and leading switch manufacturers are already offering 40 GbE blades and more than 25% of data centers have implemented these next generation speeds. It is anticipated that by the end of 2013, nearly half of all data centers will follow suit. Today’s enterprise businesses are therefore seeking the most effective method to migrate from current 10GbE data center applications to 40/100 GbE in the near future. For 40 GbE, a 12-fiber MPO connector is used. Because only 8 optical fibers are required, typical 40 GbE applications use only the 4 left and 4 right optical fibers of the 12-fiber MPO connector, while the inner 4 optical fibers are left unused as shown in Figure 1. To run 100 GbE, two 12-fiber MPO connectors can be used—one transmitting 10 Gbps on 10 fibers and the other receiving 10 Gbps on 10 fibers. However, the recommended method for 100 GbE is to use a 24-fiber MPO style connector with the 20 fibers in the middle of the connector transmitting and receiving at 10 Gbps and the 2 top and bottom fibers on the left and right unused as shown in Figure 2. CommScope’s data center fiber trunking and interconnect solution allows enterprise data center managers to effectively migrate from 10 GbE to 40/100 GbE. By leveraging 24-fiber trunk cable technology, CommScope offers the right 10-40-100 GbE migration path with: • Support for 10, 40 and 100 GbE • Maximum utilization of deployed fibers • Space savings and reduced congestion • Better airflow and energy efficiency Figure 1: For typical 40 GbE applications, the 4 right and 4 left fibers of a 12-fiber MPO connector are used for transmit and receive while the inner 4 fibers are left unused. • Increased density in fiber panels • Easier, cost-effective migration scheme • Overall better return on investment Figure 2: For 100 GbE applications, the middle 20 fibers are used for transmitting and receiving 10 Gbps while the 2 fibers on the left and 2 fibers on the right are left unused. To keep costs down, the objective of the IEEE was to leverage existing 10 GbE VCSELs and OM3/OM4 multimode fiber. The standards therefore relaxed transceiver requirements, allowing both 40 and 100 GbE to use arrayed transceivers containing either 4 or 10 VCSELs and detectors, accordingly. This prevented the cost of 40 GbE transceivers being four * ”Global Mobile Data Traffic Forecast Update, 2011- 2016,” Cisco Visual Networking Index, February 2012. 2 For more information, visit commscope.com times that of existing 10GbE transceivers for 40 GbE, or 10 times the cost of existing 10 GbE transceivers for 100 GbE. According to IEEE 802.3ba standard, multimode optical fiber supports both 40 and 100 GbE over link lengths up to 150 meters when using OM4 optical fiber and up to 100 meters when using OM3 optical fiber. cable provides a single 100 GbE link. Why is this more advantageous than using 12-fiber trunk cables? It all comes down to a better return on investment and reduced future operating and capital expense. Maximum Fiber Utilization As mentioned previously, 40 GbE uses eight fibers of a 12-fiber MPO connector, leaving four fibers unused. When using a 12-fiber trunk cable, those same four fibers are unused. For example, three 40 GbE links using three separate 12-fiber trunk cables would result in a total of 12 unused fibers, or four fibers unused for each trunk. It is important to note that singlemode fiber can also be used for running 40 and 100 GbE to much greater distances using wavelength division multiplexing (WDM). While this is ideal for longer reach applications like long campus backbones, metropolitan area networks and other longhaul applications, the finer tolerances of singlemode fiber components and optoelectronics used for sending and receiving over singlemode are much more expensive and are therefore not feasible for most data center applications of less than 150 meters. Copper twinax cable is also capable of supporting 40 and 100 GbE but only to distances of 7 meters. According to a data center study conducted by Building Services Research and Information Association (BSRIA) that surveyed 335 respondents in six countries, 29% of respondents plan to use OM3/OM4 multimode fiber for 40 GbE and 41% plan to use OM3/OM4 for 100 GbE. On the other hand, only 11% plan to use copper twinax for both 40 and 100 GbE applications. Table 1 shows the 40 and 100 GbE standards with their associated cabling media and link lengths. Standard Cable Medium Link Length 40GBASE-CR4 Copper Twinax 7m 40GBASE-SR4 Multimode Fiber 100 m OM3 150 m OM4 40GBASE-LR4 Singlemode Fiber 10 km 100GBASE-CR10 Copper Twinax 7m 100GBASE-SR10 Multimode Fiber 100 m OM3 150 m OM4 100GBASE-LR4 Singlemode Fiber 10 km 100GBASE-ER4 Singlemode Fiber 40 km With the use of 24-fiber trunk cables, data center managers actually get to use all the fiber and leverage their complete investment. Running three 40 GbE links over a single 24-fiber trunk cable uses all 24 fibers of the trunk cable. This recoups 33% of the fibers that would be lost with 12-fiber trunk cables, providing a much better return on investment. At 100 GbE which requires 20 fibers, a total of four fibers are left unused when using either two 12-fiber trunk cables or when using a single 24-fiber trunk cable. However, additional benefits come into play for 100 GbE and 12-fiber trunk cables are not the recommended configuration for 100 GbE. Figure 3 shows the ratio of 24-fiber trunk cables to corresponding connector types for each application. Figure 3: A single 24-fiber trunk cable provides twelve 10 GbE links, three 40 GbE links and a single 100 GbE link. Table 1: IEEE standards for 40 and 100 GbE Reduced Cable Congestion 24 — The Right Migration Path Another benefit to using 24-fiber trunk cables is less cable congestion. Space is at a premium in the data center, and congested cable pathways make cable management more difficult and impede proper airflow needed to maintain efficient cooling and subsequent energy efficiency. CommScope’s 24-fiber trunk cables are only appreciably larger than 12-fiber trunk cables at 3.8 mm in diameter, compared to 3 mm. That means the 24-fiber trunk cables provide twice the amount of fiber in less than 21% more space. For a 40 GbE application, it takes three 12-fiber trunk cables to provide the same number of links as a single 24-fiber trunk cable—or about 1-1/2 times more pathway space (see Figure 4). Knowing that 40 and 100 GbE are just around the corner, and already a reality for some, many data center managers are striving to determine which physical layer solution will support 10 GbE today while providing the best, most effective migration path to 40 and 100 GbE. While many solutions on the market recommend the use of 12-fiber multimode trunk cables between core switches and the equipment distribution area in the data center, CommScope recommends and offers a better standards-based migration path with the use of 24-fiber trunk cables. The use of 24-fiber trunk cables between switch panels and equipment is a common-sense approach. In this scenario, 24-fiber trunk cables with 24-fiber MPOs on both ends are used to connect from the back of the switch panel to the equipment distribution area. For 10 GbE applications, each of the 24 fibers can be used to transmit 10 Gbps, for a total of 12 links. For 40 GbE applications, which requires 8 fibers (4 transmitting and 4 receiving), a 24-fiber trunk cable provides a total of three 40 GbE links. For 100 GbE, which requires 20 fibers (10 transmitting and 10 receiving), a 24-fiber trunk 6.0 mm 3 x 12 F Trunks 3.8 mm 1 x 24 F Trunk Figure 4: 24-fiber trunk cables provide twice the fiber in less than 21% more space 3 For more information, visit commscope.com Increased Fiber Density Because 24-fiber MPO connectors offer a small footprint, they can ultimately provide increased density in fiber panels at the switch location. With today’s large core switches occupying upwards of 1/3 of an entire rack, density in fiber switch panels is critical. CommScope’s data center fiber trunking and interconnect solution consists of the 24-fiber trunk cables from the back of the fiber panels to the equipment distribution area. With the rack or cabinet, hydra cables plug into the 24-fiber MPO ports on the front of the fiber panel and connect to individual switch ports. Hydra cables feature a single 24-fiber MPO connector on one end and either 12 duplex LC connectors on the other end for 10 GbE applications, 12-fiber MPO connectors for 40 GbE or a 24-fiber MPO connector for 100 GbE. With a single 1RU fiber panel able to provide a total of 32 MPO adaptors, the density for 10 GbE applications is 384 ports in a 1RU (duplex LC connectors) and 96 40 GbE ports in a 1 RU (12-fiber MPOs). Table 2 demonstrates the various densities provided by CommScope’s data center fiber trunking and interconnect solution for 10 GbE, 40 GbE and 100 GbE applications. Figure 5: Hydra cable with a 24-fiber MPO on one end and 12 duplex LCs on the other end Application Hydra Cable Configuration 24-fiber MPO Panel Ports 1 RU Port Density 4 RU Port Density 10 GbE 24 MPO to 12 duplex LCs 32/blade 384 1536 40 GbE 24 MPO to 2 12 MPOs 32/blade 96 384 100 GbE 24 MPO to 24 MPO 32/blade 32 128 Table 2: CommScope’s fiber panel port densities Easier, Cost-effective Migration Path CommScope’s data center fiber trunking and interconnect solution offers a simple and cost effective migration path from 10 GbE to 40 and 100 GbE, providing future proofing for three generations of active equipment. With 24-fiber trunk cables effectively supporting all three applications, there is no need to recable the pathways from the back of the switch panel to the equipment distribution area—all of that cabling remains permanent and never has to be touched as shown in Figure 6. That means that data center managers can easily migrate to higher speeds, with less time and complexity. With 24-fiber trunk cables that offer guaranteed performance for 10, 40 and 100 GbE, upgrading the cabling infrastructure is as simple as upgrading the hydra cables or cassettes and patch cords to the equipment. or 100G* 100G† 100G† *100G implemented as 4x25G †100G implemented as 10x10G Figure 6: With CommScope’s data center fiber trunking and interconnect solution, 24-fiber trunk cables remain permanent for 10, 40 and 100 GbE applications. An Overall Better Return on Investment CommScope’s data center fiber trunking and interconnect solution is ideal for a medium-to-large data center customers and markets, from healthcare and finance, to broadcasting and government—essentially anyone that foresees the need to update from 10 to 40/100 GbE in the future. With guaranteed support for all three applications, the ability to use all the fiber deployed, reduced cable congestion and better airflow, higher port density in fiber panels, and an easy migration scheme, CommScope’s data center fiber trunking and interconnect solution with 24-fiber trunk cables offers lower future capital and operating expense. Unlike other solutions on the market that leave one-third of the fiber investment stranded, impede airflow with over-congested pathways, and provide inadequate port densities, CommScope’s data center fiber trunking and interconnect solution helps data center managers effectively and efficiently support today’s high-speed requirements. With permanent 24-fiber trunk cables that eliminate the need for complete and complex reconfigurations all the way from the switch to the equipment, CommScope’s data center fiber trunking and interconnect solution offers an easy, cost-effective method for upgrading from 10 GbE to 40 and 100 GbE. As the amount of data being created, processed and stored reaches an all time high, data center managers need to prepare themselves today to migrate to 40/100 GbE tomorrow. With increasing concerns about the cost to upgrade and the complexity involved, data center managers need a solution that simplifies the process and provides better return on investment, while meeting both current and future current needs. CommScope’s data center fiber trunking and interconnect solution is the right migration path to 40/100 GbE. www.commscope.com Visit our website or contact your local CommScope representative for more information. © 2015 CommScope, Inc. All rights reserved. All trademarks identified by ® or ™ are registered trademarks or trademarks, respectively, of CommScope, Inc. This document is for planning purposes only and is not intended to modify or supplement any specifications or warranties relating to CommScope products or services. AN-314288.3-AE (12/15) or 100G*