博文

目前显示的是 三月, 2017的博文

Several 100G DWDM Solutions for Arista 7500E Series

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To keep up with the global demand for higher bandwidth, Arista has designated 7500E series switch to address 100G long-hual dense wavelength division multiplexing (DWDM) connectivity. Arista 100G interconnect solution combines Layer 2/Layer 3 switching, wire-speed encryption and coherent DWDM into a high-density line card for the Arista 7500E data centers. Along with the introduction of Arista 7500E series switches, this article will illustrate several 100G DWDM solutions for distance up to 80 km, 150 km and 3000 km as well. Arista 7500E Series Switch & Line Card Arista 7500E series is the second generation of 7500 series switch that delivers scalable and deterministic network performance for mission critical data centers, enterprise and HPC environments. Available in a compact 7RU (4-slot) or 11RU (8-slot), Arista 7500E offers over 30Tbps of total capacity for 1,152 ports of 10GbE, 288 ports of 40GbE and support for 96-port 100GbE with a broad choice of interface types that suppo…

Cost Comparison : Single-mode Vs. Multimode Fiber Optics

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There is the long-term debate between single-mode and multimode optics. From the data rate, link distance, and costs, people usually will calculate every single difference between them. However, this article will not talk about the technical distinctions because you can find the related information everywhere. Cost, as one of the important factors, is sometimes the deciding point by many data center operators. The cost difference between single-mode and multimode optics (optical transceiver modules and fiber optic cables) are quite obvious. Single-mode optics with longer transmission distance and more bandwidth, usually charges higher than multimode optics. The following part will take FS.COM’s Cisco compatible single-mode and multimode optics as an example, and make a vivid comparison between these optics from 1Gbps to 100Gbps. SMF Vs. MMF Modules In order to cope with the ever-lasting requirement for higher data rate and reliable fiber performance, telecommunication industry launche…

DAC Twinax for Top of Rack Switching

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Top of rack switching as the basic data center architecture, requires one or two access switch installed on the top pf each sever rack, which provides easy cable management and maintenance. Additionally, it reduce the cable requirement as all sever connections are terminated to its own rack. Direct attach cables (DAC) twinax cable can achieve interconnection up to 15 m at 10 Gbps or 40 Gbps with low power. Most server gears come default with DAC twinax cables in-rack along with a couple of short-throw lasers back to core. This article will present the cabling solutions of the DAC cables for data center top of rack deployment. Why Use DAC Twinax Instead of Cat5e or Cat6 Cables for Top of Rack Switching? What media option would be the best to invest in for top of rack application? Category copper cable (Cat5e or Cat6) used to be the preferable options. Cat5e or Cat6 cables, standardized on 10GBASE-T, are overall cheap, backward compatible and much easier for cable management, especially…

QSFP+ to SFP+ Adapter (QSA) Module Vs. QSFP+ to SFP+ Breakout Cable

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People frequently ask about feasible solutions between 10G and 40G servers. QSFP+ breakout cables like QSFP+ to 4 SFP+ cables and MTP to 4 LC harness cables are the commonly used equipment to connect between QSFP+ ports and SFP+ ports. But recently, Cisco launched a new type of product—QSFP+ to SFP+ Adapter (QSA) module that could provide a smooth migration to 40 Gigabit Ethernet. Is it a better solution for the 10G to 40G migration? Should I use the QSA module or 40G QSFP+ breakout cable? This article will answer the above questions and provide some suggestions to you. QSA Module—Is It a Better Solution for the 40G Migration? The QSFP+ to SFP+ Adapter module, specified by Cisco, is the module built in QSFP+ form factor with a receptacle for SFP+ cable connector at the back (seen in the below image). When connecting the QSFP port to an SFP+ port, QSA module usually acts as an interface for SFP+/SFP cables. That means you can effectively plug in an SFP+/SFP optics operating at a 10 Gbp…