Networking

As we all know, 40GBASE-SR4 QSFP+ transceivers usually use a parallel multimode fiber (MMF) link to achieve 40G. It offers 4 independent transmit and receive channels, each capable of 10G operation for an aggregate data rate of 40G over 100 meters of OM3 MMF or 150 meters of OM4 MMF. However, for 40GBASE-LR4 QSFP+ transceivers, there are two kinds of links. One is coarse wavelength division multiplexing (CWDM) and the other is parallel single-mode fiber (PSM). What’s the difference between them? In this article, I will show their working principles to you respectively. 40GBASE-LR4 CWDM QSFP+ Transceiver The 40GBASE-LR4 CWDM QSFP+ transceiver, such as QSFP-40GE-LR4, is compliant to 40GBASE-LR4 of the IEEE P802.3ba standard. It contains a duplex LC connector for the optical interface. The maximum transmission distance of this transceiver is 10km. To minimize the optical dispersion in the long-haul system, single-mode fiber (SMF) has to be used. T...

40GbE Overview 40GbE (Gigabit Ethernet) is Ethernet standard developed by the IEEE 802.3ba task force, enabling the transfer of Ethernet frames at speeds of up to 40 gigabits per second (Gbps). It also addresses physical layer specifications for communication across backplanes, copper cabling, multimode fiber and single-mode fiber. 40GbE standard was approved as an IEEE standard on 17 June 2010. Now, 40 Gigabit Ethernet is already upon us. It become a new generation of high-speed, high-demand, computing applications and technologies. Like 1GbE or 10GbE network, the heart of the 40GbE network layer is a pair of transceiver modules which are connected by a patch cable. The transceiver modules and patch cables seem to be the most basic components for transmission. The former is used to plugged into either network servers or various of components such as interface cards and switches. Transceivers 40GbE transceivers are being developed along several standard form factors. CFP (C ...

If you are in a data center, wipe your finger on a distribution cabinet or a patch panel. Then watch your finger, can you see the scene shown in the following picture? Your finger is attached with dust or dirt. This situation is so familiar to most telecom engineers working in data centers. However, how many people really care about it? You might recognize that the data center needs cleaning, but you might just think about it. This is the contaminant that can be seen and checked directly by eyes or touching. How about those dust or dirt inside the equipment? Over time, without timely cleaning, the accumulation of dirt and dust will lead to problems like overheating and various network failures. This is just the start of troubles, more are there to be deal with, if no proper action was taken. Why Clean the Data Center? What would happen, if there is no regular cleaning in data center? As mentioned, the most direct result of contaminant is overheating. Why? Dust  and p...

Thanks to the optical fiber communication, we have been brought to a new internet society. Optical fibers reach more and more families. Optically that is called FTTH (fiber to the home), namely optical fibers installed directly into users’ homes. Besides optical fiber, passive components are also important to optical fiber communication. Many passive optical components are used in FTTH applications. Passive Optical Components In fiber optics, “passive” means the device does not require electrical-to-optical or optical-to-electrical conversion during its operation. Passive components include fiber optical connectors, adapters, attenuators, couplers & splitters, WDM filters & Mux/DeMux, optical switches, etc. First we will talk about optical splitters and filters. Optical Splitters An optical splitter is a device dividing optical power from an optical fiber into several optical fibers. A PLC (Planar Lightwave Circuit) splitter is usually used for fiber branches more ...

The color codes of indoor fiber optic cables are not only for aesthetics in the premises fiber cabling systems. Actually, they are used as a reference for users to easily identify what type of fiber is used in the systems. Thus, to understand the color codes is very necessary to people who need to interact with the fiber optic cables. Overview Cables with colored jackets are typically used only in intra-building applications. The color codes that are used to help identify which type of fiber cable it is and the level of fire resistance are specified by TIA-598C. It is necessary to note that the cable color codes specified in EIA/TIA 568 (standard for premises cabling) are the same as TIA-598C. However, you should be know that outdoor cables are not included in this standard. Because most cables deployed outside incorporate additives in the jacket material to withstand the damaging effects of solar radiation and other harsh environments, these outside cable products typicall...

When optical transceivers was first deployed, verifying the performance of it was straightforward. The entire network was installed and owned by a single company, and if the system worked, extensive testing of the subcomponents was unnecessary. Today, however, most optical networks use components that may come from a variety of suppliers. Therefore, to test the compatibility and interoperability of each fiber optic transceiver becomes particularly important. How to test a fiber optic transceiver? This article may give you the answer. As we all know, basically, a fiber optical transceiver consists of a transmitter and a receiver. When a transmitter through a fiber to connect with a receiver but the system doesn’t achieve your desired bit-error-ratio (BER), is the transmitter at fault? Or, is it the receiver? Perhaps both are faulty. A low-quality transmitter can compensate for by a low-quality receiver (and vice versa). Thus, specifications should guarantee that a...

Fiber optic network is gradually replacing copper network, because of its various advantages, like high speed, high density and high bandwidth, etc. Among which is that fiber optic cable can support much further distance than that of traditional copper cables like coax cable or twisted pair wire. However, in practice, the exact distance that fiber optic can support are limited by many factors. Transmission distance has become one of the biggest problems in the super fast optical communication. On one hand, with the expansion of the fiber optic network, distances for the optical links span meters to hundreds of meters and even kilometers. On the other hand, optical signal becomes weak over long distance. Stuck in this dilemma, many components and methods are being used to break the limitation of the transmission distance. This article will focus on the main factors that limit optical transmission distance. Fiber Optic Cable Type Generally, the maximum transmission distan...

Do you still worry about the costs for transceiver modules which keep adding up over time? Wanna use the compatible transceiver but still worry about the quality and compatibility? To most of the transceiver users, they are in the same psychological warfare when choosing the transceivers—to acquire a product that is with high quality and high compatibility, and also can help save more budget. Fiberstore, a professional manufacturer and supplier of compatible optical transceiver modules, may be your ideal choice. Today, let’s to gain insight into Fiberstore and its transceiver modules. 1. The transceiver can’t be compatible with your original-brand switch. 2. The quality of the transceiver is not reliable and the service life is short. 3. Poor performance. 4. Others, such as refurbished modules, power consumption etc. In Fiberstore, you can completely relieved. The above worries all do not have to worry. Why? Wide Compatibility ...