Issue link: https://www.e-digitaleditions.com/i/1219491
April/May/June 2020 I 19 and MPO connector is also defined by an intermateabil- ity standard. In other words, the same transceiver that is purchased for a data center in New York can also be used in London or Shanghai. This is also true for the LC connectors. While the performance characteristics of all the fiber optic cables must meet the same criteria, they are subject to different codes, standards and regulations based on the geographic location of the data center. These can and do lead to physical differences, which in turn can and do lead to different installation requirements. For example, in the United States, fiber optic cable installed within buildings is subject to Article 770 of the National Electrical Code (NEC). This defines various degrees of flame retardance depending on where the Cable performance and application specifications are defined by TIA (U.S and Canada) and ISO (many countries across the globe). As data rates increased, improved transmission performance grades were needed for both copper and optical fiber. However, the relation- ship between the component cable and connectors was also defined by these standards bodies. This circular relationship, between IEEE defining the communication needs and TIA/ISO defining the channel specifications, has served the industry well over the years (Figure 1). As a global standards body, BICSI produces technical manuals and standards for best practices based on indus- try regulations, codes, and other standards (e.g., TIA, IEEE, CENELEC, ISO/IEC) that form the foundation of knowl- edge required for the BICSI professional credentials and certifications of ICT designers, installers, project manag- ers, and technicians worldwide. Recently, specific appli- cations have warranted their own cabling standards. The data center was one of these applications. The relevant standard for TIA is TIA-942-B. For ISO/IEC the content is split between ISO/IEC 11801-5 (cabling) and ISO/IEC 14763-2 (pathways, spaces). With a succession of successful, aligned standards, one might think that the cabling layout for all data cen- ters can be specified using the same template. However, there are dramatic differences in how cabling is used in various types of data centers. Designers and installers should be aware of how and why these differences exist to best serve the data center customer. THE DEVELOPMENT CYCLE – 10BASE-T – 100BASE-T – Gigabit Ethernet • Fiber • Twisted Pair – 10 Gigabit Ethernet • Fiber • Twisted Pair – 40/100 Gigabit Ethernet – 20/400 Gigabit Ethernet – Category 3 – Category 4 – Category 5, 5e – OM1/2 – Category 6a – OM3 – OM4 – OM5 – MPO Polarities FIGURE 2: Layer 1 optical link. TRANSCEIVER TRANSCEIVER CABLING FIGURE 1: The development cycle between IEEE and TIA. GLOBAL DISTINCTIONS When one thinks about a basic Layer 1 optical connection in a data center, it is commonly a pluggable SFP transceiver, an LC-LC patch cord, a multi-fiber trunk cable, another LC-LC patch cord, back to another pluggable SFP (Figure 2). In the list of components, the SFPs and the LC connectors are exactly the same in all parts of the world. The SFP or QSFP, QSFP-DD, OSFP, transceiver is defined by its associated standard or multi-source agreement (MSA). The LC