Offering considerable improvements from previous FC speeds, 16 Gbps FC uses 64b/66b encoding, retimers in modules, and transmitter training. Doubling the throughput of 8 Gbps to 1,600 Mbps, it uses 64b/66b encoding to increase the efficiency of the link. 16 Gbps FC links also use retimers in the optical modules to improve link performance characteristics, and electronic dispersion compensation and transmitter training to improve backplane links. The combination of these technologies enables the 16 Gbps FC to provide some of the highest throughput density in the industry, making data transfers smoother, quicker, and cost-efficient.
Although 16 Gbps FC doubles the throughput of 8 Gbps FC to 1600MBps, the line rate of the signals only increases to 14.025 Gbps because of a more efficient encoding scheme. Like 10 Gbps FC and 10 Gigabit Ethernet (GbE), 16 Gbps FC uses 64b/66b encoding, that is 97% efficient, compared to 8b/10b encoding, that is only 80% efficient. If 8b/10b encoding was used for 16 Gbps FC, the line rate would have been 17 Gbps and the quality of links would be a significant challenge because of higher distortion and attenuation at higher speeds. By using 64b/66b encoding, 16 Gbps FC improves the performance of the link with minimal increase in cost.
To remain backward compatible with previous Fiber Channel speeds, the Fiber Channel application specific integrated circuit (ASIC) must support both 8b/10b encoders and 64b/66b encoders.
As seen in Figure 2-1, a Fiber Channel ASIC that is connected to an SFP+ module has a coupler that connects to each encoder. The speed-dependent switch directs the data stream toward the appropriate encoder depending on the selected speed. During speed negotiation, the two ends of the link determine the highest supported speed that both ports support.
The second technique that 16 Gbps FC uses to improve link performance is the use of retimers or Clock and Data Recovery (CDR) circuitry in the SFP+ modules. The most significant challenge of standardizing a high-speed serial link is developing a link budget that manages the jitter of a link. Jitter is the variation in the bit width of a signal due to various factors, and retimers elliminate most of the jitter in a link. By placing a retimer in the optical modules, link characteristics are improved so that the links can be extended for optical fiber distances of 100 meters on OM3 fiber. The cost and size of retimers has decreased significantly so that they can now be intergrated into the modules for minimal cost.
The 16 Gbps FC multimode links were designed to meet the distance requirements of the majority of data centers. Table 2-2 shows the supported link distances over multimode and single-mode fiber 16 Gbps FC was optimized for OM3 fiber and supports 100 meters. With the standardization of OM4 fiber, Fiber Channel has standardized the supported link distances over OM4 fiber, and 16 Gbps FC can support 125 meters. If a 16 Gbps FC link needs to go farther than these distances, a single-mode link can be used that supports distances up to 10 kilometers. This wide range of supported link distances enables 16 Gbps FC to work in a wide range of environments.
Another important feature of 16 Gbps FC is that it uses transmitter training for backplane links. Transmitter training is an interactive process between the electrical transmitter and receiver that tunes lanes for optimal performance. The 16 Gbps FC references the IEEE standards for 10GBASE-KR, which is known as Backplane Ethernet, for the fundamental technology to increase lane performance. The main difference between the two standards is that 16 Gbps FC backplanes run 40% faster than 10GBASE-KR backplanes for increased performance.
Fiberstore introduces it’s new OM4 Laser-Optimized Multimode Fiber (LOMMF) “Aqua” cables, for use with 40/100Gb Ethernet applications. These new technology, 50/125um, LC/LC Fiber Optic cables, provide nearly three times the bandwidth over conventional 62.5um multimode fiber, with performance rivaling that of Singlemode cable, at a much reduced cost. LOMMF cable allows 40/100Gb serial transmission over extended distances in the 850nm wavelength window, where low-cost Vertical Cavity Surface Emitting Lasers (VCSELs) enable a cost-effective, high-bandwidth solution. OM4 fiber optic patch cord is ideally suited for LAN’s, SAN’s, and high-speed parallel interconnects for head-ends, central offices, and data centers. Tripp Lite warrants this product to be free from defects in material and workmanship for Life. Now the following is the OM4 fiber from Fiberstore.
OM4 SC patch cord feature an extremely high bandwidth–4700MHz*km, more than any other mode. They support 10GB to 550 meters and 100GB to 125 meters. These cables are suitable for high-throughput applications, such as data storage. These cables are fully (backwards) compatible with 50/125 equipment as well as with 10 gigabit Ethernet applications. These connectors utilize a UPC (Ultra Physical Contact) polish which provides a better surface finish with less back reflection. With the OM4 cables, you can use longer lengths than OM3 cables while still having an excellent connection.
We offer a huge selection of single and multimode patch cords for multiple applications: mechanical use, short in-office runs, or longer runs between and within buildings, or even underground. Gel-free options are available for less mess, and Bend Insensitive cables for minimizing bend loss, which can be difficult to locate and resolve.
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