Networking

In today’s data center,  direct attached cable  (DAC) is widely used for interconnection. With 40G migration, DAC becomes more popular, because they can support the high data rate and complete the interconnection in short time effectively. Currently, there are three types of DACs: passive copper cable, active copper cable and active optical cable (AOC). However, different DAC have different performances and prices. Passive or active? Copper or optical? Which DAC is the one you need? In data center, the battle between performance, transmission distance and cost has never ended. This is also true to the selection of DAC for 40G data center interconnection. To find a cost-effective  40G DAC  solution for data center interconnection with reliability and stability, this article will provide you the solution by several rounds of battle between the three types of DAC. Battle Over Transmission Distance The first round of battle is transmission distance which is alwa...

Bandwidth usage is soaring, driven by the proliferation of Internet-connected devices. At this time, active optical cable (AOC) has emerged. Besides, the market of AOCs keeps growing and has a broad prospect. What’s active optical cables? Why should we use it? In this article, some knowledge of active optical cables will be provided. Introduction to Active Optical Cable (AOC) Active optical cable (AOC) is used for short-range multi-lane data communication and interconnect applications. Usually, the wire transmission of optical communication should belong to passive part, but AOC is an exception. AOC consist of multimode optical fiber, fiber optic transceivers, control chip and modules. It uses electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. Since people expect more information to be available at their fingertips, our communications systems will need ...

High speed and wide bandwidth demands drive data centers to consolidate into more complex systems. The speed of data center now is increasing to 40G and eventually to 100G. How to achieve 40G connectivity? In fact, we need some new optical technologies and cabling infrastructure. In this post, I will introduce some commonly used components for 40G connectivity. 40G QSFP+ Pluggable Optical Modules As we know, fiber optic transceiver is an electronic device that receives an electrical signal, converts it into a light signal, and launches the signal into a fiber. It also receives the light signal, from another transceiver, and converts it into an electrical signal. It is the key component in fiber optic transmission. The basic interface of 40G pluggable optical modules are 40GBASE-LR4 and 40GBASE-SR4 in QSFP+ form factor. 1. 40GBASE-SR4 QSFP+ 40GBASE-SR4 QSFP+ transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/O...