In the old days of grind-and-polish technology used in fiber optic communications, fiber patch cord installation seemed to be a difficult and hard-to get business which required a skillful specialist. But owing to the progress made in fiber optic terminations and technologies, fiber patch cables have seen extremely heavy use in telecommunications and wide area networks, since they feature high data rate capabilities, noise rejection and electrical isolation. Usually, fiber jumpers can be divided into two types: single mode patch cord and multi mode patch cord. Here "mode” refers to the transmitting mode of the fiber optic light in the fiber core. Usually the former, fiber optic patch cables single mode, are with 9/125 fiber glass typically with yellow jacket color, while the latter multi mode ones are with 50/125 or 62.5/125 fiber glass in orange color often.

Fiber optic patch cord is made of a fiber optic cable which is terminated by fiber cable connectors on both ends, meaning that fiber optic patch cable can be classified based on fiber optic connector types. For example, LC fiber patch cable means the fiber cable is with LC fiber optic connector. There are also PC, UPC, APC type fiber patch cord, different from each other because of the polish of fiber connectors. Fiber optic connectors are designed and polished in different shapes to minimize back reflection. This is particularly important in single mode applications. Typical back reflection grades are -30dB, -40dB, -50dB and -60dB. General use of these cable assemblies includes the interconnection of fiber cable systems and optics-to-electronic equipment. Image below shows several commonly-used patch cable types.

Compared with their copper wires, fiber optic jumpers have smaller diameter, lighter weight, easier for testing and installation. But their advantages are not limited to these points.

• Great Bandwidth

Fiber optic cables can carry very wide bandwidth signals, well into the GHz range. Many individual, lower bandwidth signals can be multiplexed onto the same cable. In commercial systems, fiber optic cable often carries a mixture of signal types, including voice, video and data all on the same fiber.

• Noise Immunity & Electrical Isolation

In industrial applications, one of the most important features of fiber optics is the noise immunity. Even in those conditions which are characteristics of prominent and unavoidable noise, fiber optics are unaffected. As for ground loop noise issues, the use of fiber optic patch cord can just eliminate it. Field signals, generated by devices floating at high potentials, can be coupled to other equipment at much lower potentials without the risk of damage. This is particularly preferable in industrial applications.

• Power Budget

While planning the fiber links, the most critical factor to be considered is the power budget specification of the devices being connected. This value tells you the amount of loss in dB that can be present in the link between the two devices before the units fail to perform properly. This value includes line attenuation as well as connector loss.

It’s necessary to mention that fiber optic patch cord is different from the fiber optic pigtail. The former consists of three parts: fiber optic connector+ fiber optic cable+ fiber optic connector, in contrast, the latter includes only two sectors: fiber optic connector+ fiber optic cable. Or put it in another way, when the cable is terminated with fiber connectors on both ends, it’s fiber optic jumper, and when the fiber connector is attached to only one end of the cable, it’s called a fiber optic pigtail.

Although fiber patch cords have been common for many years, there are still some myths about them.

Some people think that fiber jumper is more expensive than its counterpart copper. Actually, since manufacturing costs become down with each passing day, patch cord is less costly than the equivalent copper installation. Once deployed, the subsequent patch cord maintenance cost is also significantly less what copper requires.

It’s true that when terminating fiber cable, attention and care should be taken to avoid breaking the glass core, and some may think that patch cord is very fragile. But in practical use, fiber jumper has proven to be more robust than copper, able to withstand a higher pulling tension than copper, rated for larger temperature ranges.

Fiber patch cords play an important role in completing the end-to-end connections, ideally to be used in industrial and commercial systems. As professional fiber optic product supplier, Fiberstore offers various kinds of patch cords at affordable prices, including LC fiber patch cable mentioned above, SC patch cord, MTP/MPO cable, single mode and multi mode patch cords. If you want to know more information about patch cables or buy such cables for your networking use, please visit Fiberstore.

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In this big data age featuring high data transmission speed and great capacity, opticalcomponent transmission technology has experienced a crustal movement with each day passing by. The continuous demands of high-definition images, various voice and massive data transmission services, and many Internet and intelligent terminals application, have driven the bandwidth usage to a soaring point. With the advancements in fiber optics technology to meet the demanding bandwidth speeds, active optical cables (AOCs) have emerged. As copper connectivity faces some limitations such as low bandwidth, AOCs have been preferred to accelerate data connectivity for storage, networking, and high-performance computer (HPC) applications.

You may feel at a loss about what is AOC? Why should focus on this product? Here, let’s start with its definition.

An AOC is a wiring technology which accepts the same electrical inputs as a conventional copper cable, but makes use of optical fiber between the connectors. In order to improve the cable’s distance and speed performance without sacrificing its compatibility with standard electrical interfaces, the AOC uses electrical to optical conversion on the cable ends. More specifically, AOC is basically to convert electrical signal into optical signal at Tx, then transfer signal through anti-electromagnetic fiber optics intermediate, and vice versa at Rx, so that high-speed optical signal can flow smoothly in both ends. Its smart integration of optical and electrical interfaces thanks to the packaging design has expanded its applications from high performance computers to traditional data centers with the support of many protocols. (Active optical cables are reliant on protocol named InfiniBand.). Image below shows the AOC structure.

Key advantages of AOCs include: low weight for high port count architectures; small bend radius for easy installations; and low power consumption enabling a greener environment thereby providing the lowest total cost solution for data centers. At present, AOC is widely used in many fields, such as short-range multi-lane data communication and interconnect applications, to promote the traditional data center to step into optical interconnection.

Being one of the fastest growing technologies in the data center space, AOC has much to offer. It supplies higher bandwidth and a longer reach with a better footprint than current copper cables. When compared to the incumbent copper cables in most cases, active optical cables provide lighter weight, a smaller size, EMI immunity, a lower interconnection loss, and reduced power requirements. It seems that this kind of cable has nothing to "complain about”, but AOC is such a smart inventor that distinguishes from their predecessors and makes them look obsolete.

In the telecommunication market, a wide range of AOCs have been released for different applications, like 40G QSFP+ to QSFP+ AOCs (QSFP cables). Besides, FOR 40GbE applications, there are also fan-out products with one QSFP+ module (ie. AFBR-79EQPZ) at one end of the AOC and several lesser data rate SFP+ modules (eg. SFP-10G-SR) at the other. These can be used to connect a switch port to multiple server ports.

In addition to 40Gbps, AOCs operating at 100Gbps have also been available in the market for several years. In 100GbE environment, CFP is used for longer distances—typically over 100 meters and up to 40km—while QSFP and CXP is used for shorter distances. And the current cabling application of 100G QSFP28 AOC is one QSFP28 to four SFP28 cables, something similar to that 40G QSFP+ AOC assembly. There seems to be few AOCs that have adopted CFP at the present time.

AOCs provide a direct electrical connection between corresponding cable ends by embedding optics and/or electronics within the connectors. Fiberstore AOCs are provided for HPC, storage and networking applications. Many AOC products are available, including 10G SFP+ AOCs, QSFP cables mentioned above, compatible with Generic, Cisco, Brocade and some other brands. Certainly, AOCs can also be customized to meet your length requirements. For more information, please visit Fiberstore.

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To meet the growing requirements of collaborative multimedia services and applications, to respond to the fast-changing traffic patterns, and to better accommodate users’ bandwidth demands, 100G connections have been positioned for significant growth in data centers with the introduction of the latest 100G optical modules. The upgrade to 100Gbps is not more than gaining capacity. It’s also about gracefully evolving your network at your own pace to achieve greater efficiency, streamline costs and support new services. Many systems now support four or more 100G ports on each line card, with some systems supporting many hundreds of 100G ports. 100G optical modules, as an integral part of the overall system design, support highly reliable operations, optimized for entire architecture. This article puts its focus on one predominant 100G form factor: QSFP28.

100G QSFP28 transceivers are commonly seen in two types: QSFP28 100GBASE-SR4 (QSFP28 SR4) and QSFP28 100GBASE-LR4 (QSFP28 LR4), designed with four 25Gbps lanes for high port-count 100G data center applications, enabling the implementation of various reaches in the QSFP28 MSA form factor in 100G systems. They allow for greater port density, lower power consumption and significantly lower cost of ownership for 100G connectivity. With these optical transceivers, state-of-the-art 100Gbps performance and new levels of infrastructure consolidation have been made possible.

The QSFP28 100GBASE-SR4 transceiver is a parallel 100Gbps QSFP28 optical module designed with form factor, optical/electrical connection and digital diagnostic interface according to the QSFP28 Multi-Source Agreement (MSA). It offers 4 independent transmit and receive channels, each capable of 25Gbps operation for an aggregated data rate of 100Gbps for 100 meters on 12-fiber MPO/MTP OM4 multi-mode fiber (MMF). Often, an optical fiber ribbon cable with an MTP/MPO connector can be plugged into the QSFP28 module receptacle for high functionality and feature integration. Proper alignment is ensured by the guide pins inside the receptacle. The cable usually cannot be twisted for proper channel to channel alignment.

The QSFP28 SR4 module is a vertically integrated solution that meets IEEE 802.3 standards and MSA requirements with power dissipation well under 3.5W. It supports both 100GBASE-SR4 as well as 4x25G breakout applications, say 100G QSFP28 to QSFP28 DAC and 100G QSFP28 SR4 to 4x25G SFP28 break-out cables, meeting the harshest external operating conditions including temperature, humidity and EMI interference.

• QSFP28 100GBASE-SR4 Working Principle

QSFP28 SR4 transceiver converts parallel electrical input signals into parallel optical signals, by a driven Vertical Cavity Surface Emitting Laser (VCSEL) array. The transmitter module accepts electrical input signals compatible with Common Mode Logic (CML) levels. All input data signals are differential and internally terminated. The receiver module then converts parallel optical input signals via a photo detector array into parallel electrical output signals. The receiver module outputs electrical signals are also voltage compatible with Common Mode Logic (CML) levels. All data signals are differential and support a data rates up to 25Gbps per channel. The following figure shows the functional block diagram of this module.

The QSFP28 100GBASE-LR4 transceiver is also a 100Gbps transceiver module designed for optical communication applications, compliant to 100GBASE-LR4 of the IEEE P802.3ba standard. This module converts 4 input channels of 25Gbps electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gbps optical transmission. Reversely on the receiver side, the module de-multiplexes a 100Gbps optical input into 4 channels of LAN WDM optical signals and then converts them to 4 output channels of electrical data. The high performance cooled LAN WDM EA-DFB transmitters and high sensitivity PIN receivers provide superior performance for 100GbE applications up to 10km links over single-mode fibers (SMFs) and compliant to optical interface with IEEE802.3ba Clause 88 100GBASE-LR4 requirements.

• QSFP28 100GBASE-LR4 Working Principle

The transceiver module receives 4 channels of 25Gbps electrical data, which are processed by a 4-channel Clock and Data Recovery (CDR) IC that reshapes and reduces the jitter of each electrical signal. Subsequently, each of 4 EML laser driver IC's converts one of the 4 channels of electrical signals to an optical signal that is transmitted from one of the 4 cooled EML lasers which are packaged in the Transmitter Optical Sub-Assembly (TOSA). Each laser launches the optical signal in specific wavelength specified in IEEE802.3ba 100GBASE-LR4 requirements. These 4 lane optical signals will be optically multiplexed into a single fiber by a 4-to-1 optical WDM MUX. The optical output power of each channel is maintained constant by an automatic power control (APC) circuit. The transmitter output can be turned off by TX_DIS hardware signal and/or 2-wire serial interface. Here goes the picture of QSFP28 100GBASE-LR4 module functional block diagram.

100G connectivity is now ready for widespread deployment. With so many 100G modules (CFP, CFP2, CFP4 and QSFP2 having been introduced in the market, the number of companies deploying 100GbE networks is sure to see a significant growth. Although the expense of 100G connectivity maybe an issue for some companies, further developments which are under way are expected to reduce the cost.

100G QSFP28 transceivers enable higher speeds, greater scalability, and higher levels of performance and reliability, so as to better meet business demands. To optimize business investment, Fiberstore supplies many 100G QSFP28 modules which experience rigorous qualification and certification testing, sold at affordable prices. Besides QSFP28 transceivers, QSFP28 cable can also be found here. If you want to know more information about QSFP28 optics, you can visit Fiberstore.

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The number of cloud applications, virtualized workloads, coupled with a host of devices housed in data centers, all these increase at an amazing speed in this technological world. When walking past the data center, you may hear such a call for more capacity and greater performance from your servers. This call doesn’t slack with everyday passing, but it grows vigorously. In order to accommodate these applications that require higher data transport rates, it’s not advised to sit still for some enterprises. If your data center hasn’t shifted from 10Gbps to 40Gbps infrastructure, now it’s your chance by deploying 40GbE with BiDi QSFP+ optics (ie. Cisco QSFP-40G-SR-BD) at lower costs than using 40G QSFP+ optics.

BiDi stands for "bi-directional”. This new BiDi optical technology is available only from Cisco. Cisco BiDi optics is a standard QSFP, MSA-compliant optical connector that can operate with any Cisco switch that supports QSFP modules and connects with any vendor’s standards-compliant equipment. It uses two different wavelengths on the same fiber, with one wavelength headed in one direction and the second wavelength traveling in the other direction.

BiDi technology uses specialized, multilayer, thin-film dielectric coating and lensing, which allows components to pass and reflect optical signals at the same time. And it uses Bidirectional Optical Sub-Assembly (BOSA) technology to support two wavelengths (20Gbps total) on each fiber. Each QSFP can deliver 40Gbps over the same duplex multi-mode fiber (MMF) cabling you use right now.

Inside this module, four channels each of 10Gbps signal transmission and reception are converted to two bidirectional channels of 20Gbps signals over two different wavelengths (usually 850nm and 900nm) respectively. BiDi optics represents a new solution to deploy 40GbE that meets all 40GBASE-SR4 performance criteria. The signal is sent to a target device via 850nm on one fiber. Then the signal from the target device is sent via 850nm on the other fiber. This also works for signals on 900nm, as is shown in the following image. To put it simply, BiDi provides 40GbE on two MMFs and duplex LC connectors, just like the existing 10G infrastructure that is deployed today.

With 40G BiDi, upgrading from 10G to 40G is much easier: to replace the existing 10G optical modules with 40G BiDi optical modules.

For instance, in 10GbE transmission, 10GBASE-SR optics uses two MMFs and duplex LC connectors for transmitting on one of the fibers and receiving on the other fiber. As for current 40GbE, 40GBASE-SR4 (eg. 40G-QSFP-SR4) uses four 10G lanes to support 40G through 12-fiber trunks and patch cords terminated with MPO connectors., with four for receiving, four for transmitting and the rest four fibers unused. This difference requires the change of infrastructure when upgrading 10G network to 40G network. If the 40G BiDi QSFP+ transceiver for short distance also using the duplex transmission mode, things would be much easier. That’s why choose 40G BiDi QSFP transceiver.

Besides, with 40G QSFP+ optics only using 8 of the 12 fibers in a 12-fiber trunk, this results in the disappearance of one third of the total bandwidth available to a data center when migrating from 10G to 40GbE. If select 40G BiDi QSFP+ optics, this bandwidth disappearance can be avoided, since only a pair of cables are used.

Just as what has been mentioned above, 40G BiDi transceiver modules give you 40Gbps over your existing 10Gbps cable plant, meaning that you can connect your top-of-rack switches using the same MMF and patch cables you are using right now, to get 40Gbps performance. If you were building a new 40Gbps data center fabric the traditional way, you would need to run 8 MMF strands between your access and aggregation layers. What a costly project. But with BiDi optics, there is no need for expensive 40G migration cassettes, and no need to add additional fiber infrastructure.

In an upgrading project, cost and time are the critical factors which should be considered. 40G BiDi optical modules offer another way to deploy 40G Ethernet: it’s less costly to implement 40G Ethernet using two MMFs (vs. the 8 fibers required by 40GBASE-SR4). With 40G BiDi optics, 40Gbps performance is no longer a luxury. With 40G BiDi optics, there is no need to rewire your data center to get the next level of capacity and performance. With 40G BiDi optics, it’s possible to upgrade capacity without having to upgrade cabling, a huge cost saving. Fiberstore supplies various 40G BiDi QSFP+ transceivers for your smooth 40G migration. You can visit Fiberstore for more information about 40G BiDi transceiver modules.

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The explosive data traffic which is driven by IP video and "cloud computing” demands for optimized solutions in data centers. Such solutions taken for higher speed data rates (say 100Gbit/s) are based on advanced transceiver technologies which are engineered to make use of the full bandwidth of fibers. These advances lower costs, increase efficiency, and make 100G applicable to a wider variety of carrier and data center applications. Nowadays, as 100Gbps transmission is becoming accessible, 100G optics hit the headline the time when they are brought to the market. Just similar to 10G interconnect solutions, there are also a set of different optical transceivers that are designed for 100G transmission, like CXP, CFP, CPAK, and QSFP28. This article mainly talks about the pluggable form-factor CFP and its later generations: CFP2, and CFP4.

When the IEEE 802.3ba committee ratified the 100 Gigabit Ethernet (GbE) standard, along with the general specification, and defined a number of fiber optic interfaces, the transceiver industry launched an alphabet soup of form factors. The CFP emerged first, "C" for 100, and FP for "Form factor, Pluggable”. Like the early versions of 10G transceivers, CFP optical transceiver form factor is huge, supporting data rates of 40 and 100Gbps. Aimed primarily at 40- and 100GbE applications, the CFP supports both single-mode fiber (SMF) and multi-mode fiber (MMF) and can accommodate a host of data rates, protocols, and link lengths.

The CFP multisource agreement (MSA) was formally launched at OFC/NFOEC 2009 in March by founding members Finisar, Opnext, and Sumitomo/ExceLight (now known as Sumitomo Electric Device Innovations USA following the merger of ExceLight and Eudyna Devices USA Inc..These founding members actually began meeting when the IEEE 802.3 Higher Speed Study Group (HSSG) was only focused on developing a standard for 100GbE. When that activity was expanded to include 40GbE in July 2007, the CFP MSA followed suit.

CFP form factor, as mentioned above, supports both SMF and MMF, as well as a variety of data rates, protocols, and link lengths, including all the physical media-dependent (PMD) interfaces encompassed in the IEEE 802.3ba Task Force, which was ratified in 2010. At 40GbE, target optical interfaces include the 40GBase-SR4 for 100 m and the 40GBase-LR4 for 10km. There are three PMDs for 100GbE: 100GBASE-SR10 for 100m, 100GBASE-LR4 for 10km (ie. CFP-100G-LR4), and 100GBASE-ER4 for 40km.

CFP form-factor enjoys several features which enable it to support a wide range of distances as well as various power dissipation. Firstly, its size is suitable for longer-reach interfaces and single-mode fiber applications. Technically, the CFP works with MMF for short-reach applications, but practically it is not really optimized in size for MMF market judging from its size, most notably because the MMF market requires high faceplatae density.

Secondly, the form factor includes a two-piece electrical connector. The connector itself features two rows, enabling improved density in its overall footprint.

The last point is that CFP is known as the riding heat sink, in which the heat sink is attached to rails on the host card and "rides" on top of the CFP, which is flat topped. The heat sink can be included or omitted depending on the thermal requirements of the host system. When included, the heat sink presses down on the module, providing a good conductive surface that is also low friction, making it very easy for the operator to insert the module into the host board.

CFP2, a new form factor specified by the CFP MSA, is also a hot-pluggable transceiver module that supports the IEEE 100GbE. Compared to the existing CFP, CFP2 is half the size of the CFP (image below) and consumes half the power. Besides, CFP2 doubles the front panel port density owing to integration of optics and ICs, and increase in electrical I/O rate from 10G to 25G.

CFP4 specifications document became available announced by MSA members in 2014. CFP4 enjoys the same features as CFP2 except that the CFP4 has a smaller size than CFP2. In addition, CFP4 quadruples front panel port density.

Pluggable CFP, CFP2 and CFP4 optical transceivers support the ultra-high bandwidth requirements of data communications and telecommunication networks that form the backbone of the Internet. CFP is widely available in the market, especially with the development of 100GbE in recent years. However, CFP2 and CFP4, due to the high cost of research and development, are still not so much widely available in the market.

100G CFP, CPF2 and CPF4 transceivers accelerate the data flow throughout your data centers, delivering significant reductions in power consumption. Fiberstore has a complete suite of 100G CFP transceivers (Cisco CFP-100G-LR4 mentioned above) for your 40G and 100G upgrading from 10G networks. Want to know more information about CFP optical transceivers and other 100G optics, you can visit Fiberstore.

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As one of the most effective approaches today for reliable and long-distance communications, fiber optic cable has attracted network designers’ notice while they take on cabling installation and upgrade projects. Undoubtedly, compared with copper, fiber optic cable delivers more bandwidth, and allows for more reliable data transmission over longer distance, say 10km distance is possible in GbE applications when used in combination with 1000BASE-LX SFP transceivers (EX-SFP-1GE-LX). To put it simply, fiber is able to carry more information with greater fidelity since finer is immune to many environmental factors that affect copper wire. However, there are many aspects that may influence the performance of fiber, such as light loss, a key issue. And such fiber light loss seems to be a top priority for network designers to consider while handling fiber optic cable. This article mainly discusses problems that cause loss and methods to fix it.

Before talking about fiber light loss, it’s imperative to have the basic knowledge about light loss.

Fiber optic signal is made of light, and when fiber optic cable carries these pulses of light between transmitters and receivers, signal loss occurs during transmission. In order to ensure the smooth data transmission, the light must arrive at the far end of the cable with enough power to be measured. Light loss between the ends of a fiber link results from multiple sources, such as the attenuation of the fiber itself, fusion splices, macro bends, and loss through adapter couplings where end-faces meet. Among these important sources that can bring a network down, dirty and damaged end-faces are the most underestimated threat. Dirty end-faces are a leading cause of fiber link failure for both installers and private network owners. Contaminated end-faces are likely to cause fault in fiber links. It’s easy to prevent, but there continues to be a lack of appreciation for this crucial issue and lots of misinformation about proper techniques.

In this passage, two sources that cause loss as light leaves one end-face and enters another inside an adapter are introduced: contamination and damage.

• Contamination

Contamination falls in many forms, from dust to oils to buffer gel. Simply touching the ferrule will immediately deposit an unacceptable amount of body oil on the end-face. Dust and small static-charged particles float through the air and can land on any exposed termination. This can be true in facilities which are under construction or renovation. In new installations, buffer gel and pulling lube can easily find its way onto an end-face.

As for such contamination, protective caps, also called "dust caps”, are one of the most common contributors. These caps are made in rapid production processes during which a mold release compound is used. Such compound is likely to contaminate end-faces on contact. What’s more, as the time goes by, the plastic cap becomes "old”, and then plasticizers would deteriorate and result in an outgas residue. Last, airborne dust itself would find its way into the protective cap and move to the end-face when the cap is pushed onto a ferrule. It’s a very common mistake to assume that end-faces are clean when patch cords or preterminated pigtails are removed from a sealed bag with protective caps in place.

• How to Avoid Such Contamination?

To avoid this problem, it’s recommended to follow the following steps. Inspection of the end-face is necessary to verify that no containments are within the field of view. The most crucial area to clean is the core of the fiber, followed by the cladding. Yet contamination on the ferrule—outside of the end face—could slide towards to core as the fiber is mated or handled. Therefore, all visible contamination should be removed if possible.

• Damage

It’s ill-advised to mate every connection first and then inspect only those that fail, as the physical contact of mated contaminants can cause permanent damage. This permanent damage would lead to more costly and time-consuming determination or replacement of preterminated links.

Scratches, pits, cracks or chips all "belong to” damage. These end-face surface short comings could attribute to the poor termination or mated contamination. Regardless of the cause, damage must be evaluated to determine if action is required, as some of it can be ignored or remedied. Up to 5% of the outer edge of fiber cladding generally may be chipped; this is a common result of the polishing process. Any chips on the core are unacceptable. If scratches or excess epoxy bleed are found, re-polishing with fine lapping paper can eliminate the problem. If the end-face is cracked or shattered, the fiber must always be re-terminated.

• How to Prevent Such Damage?

In every step taken, all end-faces should be inspected before insertion. If a connector is being mated to a port, then the port should be inspected as well. Be aware that contamination inside a port can not only cause damage but also migrate to the connector being inserted. Too often equipment ports are overlooked not only as contaminated themselves but also as a source of contamination for test cords. So, it’s a wise approach to check every equipment port before they are safe and clean to be inserted.

It’s known that fiber light loss can affect the data transmission speed and distance. This distance further depends on wavelength, and cable types, ranging from 550m with multi-mode cable with GbE modules (eg. MA-SFP-1GB-SX) and up to 40km for single-mode cable 40GbE modules (ie. QSFP-40G-ER4).

To reduce fiber light loss as much as possible, it’s of great importance to keep fiber from being contaminated or damaged. Certainly, fiber light loss sources are not limited to above-mentioned two, the intrinsic fiber core attenuation also included. Hope this text is helpful for you to avoid possible external fiber contamination and damage, so as to improve fiber performance.

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In modern fiber optic networks, various tools and gadgets which are fundamental to performing smooth networking service have been designed with the latest fiber optic technology. Among these smart inventions, one particular device—fiber optic transceiver, attracts more and more subscribers’ attention. This device has two functions that it's both a transmitter and receiver which are combined to form a unit and use the same channels to send and receive data.

In optical communication networks, fiber optic transceivers are used to connect the cabling to the network, and provide interface between the equipment and the cabling. They can be found in many form factors for different Gigabit applications: like SFP, GBIC, XFP, SFP+, CFP, QSFP+, and so on. This article mainly talks about XFP transceiver used for 10 Gigabit Ethernet (GbE) networks.

XFP specification was developed by the XFP MSA (Multi Source Agreement) Group. It is an informal agreement of an industry group, not officially endorsed by any standards body. The first preliminary specification was published on March 27, 2002. And the first public release was on July 19, 2002. XFP was adopted on March 3, 2003, and updated with minor updates through August 31, 2005.

XFP transceiver is a little form factor hot pluggable component intended for 10G system applications. The recognized standard with this transceiver is called XFP MSA, which was created by various companies. XFP is often referred to as XFI. XFI electrical interface specification was a 10 gigabit per second chip-to-chip electrical interface specification defined as part of the XFP MSA.

XFP transceivers can be plugged into routers, switches, transport gear, or pretty much any network device to transmit and receive signals. They are protocol-independent and hot-swappable while the device is operating, standardized to be interchangeable among vendors, capable of operating over many different physical medium and at different distances. XFP is optical inter-operable with 10GBASE XENPAK, and 10GBASE X2 on the same link. Judging for its size, XFP packaging is smaller than the XENPAK form-factor, which is desirable by many designers. The smaller the footprint, the easier to design it into the systems when needed.

Being the first small form factor 10GbE optics, XFP meets the relation to MSA launched by various popular companies on the market today. There are many kinds of XFP transceivers available in the telecommunication market, including 10GBASE-SR XFP, 10GBASE-LR XFP, 10GBASE-ER XFP and 10GBASE-ZR XFP.

• 10GBASE-SR XFP

10GBASE-SR XFP (ie. XFP-10G-MM-SR) is designed to work through MMF using 850nm lasers. This XFP type supports a link length of 26m on standard FDDI-grade MMF. And when using 2000 MHz/km MMF (OM3), 300m link lengths are possible. Fiberstore compatible Cisco XFP-10G-MM-SR is able to realize 300m distance reach over OM3 with the maximum data rate at 10.3125Gbps.

• 10GBASE-LR XFP

10GBASE-LR XFP is intended to operate via SMF using 1310nm lasers. The maximum link length that XFP 10GBASE-LR port type can support is 10km when it’s used in combination with high-quality optics.

10GBASE-ER XFP is able to realize the maximum link length of 40km via 1550nm SMF, and 10GBASE-ZR XFP is capable of realizing the utmost distance of 80km also by 1550nm SMF.

To those 10GbE XFP transceiver subscribers, they can either go to the local store for choice or buy it online. The question is how to find a reliable seller who supplies high-quality products at affordable prices. One of the most most widely used and reliable brands of transceivers is Cisco. Before making a decision, it’s advised to read the reviews on the web and testimonials from customers who have bought from it before. This matters a lot in your purchasing, leading to avoid unnecessary expenses on gadgets out of use.

However, the original brands are often expensive. When you have a tight budget, you can turn to third-party suppliers for compatible ones, like Fiberstore XFP transceivers which are quality-assured and fully compatible with some major brands, such as Cisco, Finisar, Juniper and HP. Most importantly, those compatible XFP transceivers are really cost-effective while they ensure the same functions as the originals.

After discussion, you have gained a deeper understanding of XFP transceivers. These hot-pluggable XFP modules allow for easy configuration and future upgrading, suitable for 10GbE networks. Fiberstore provides various types of XFP transceivers, severely checked for compatibility with tools and devices from large organizations in industry, including the above mentioned XFP-10G-MM-SR (10GBASE-SR port) and ONS-XC-10G-S1. For more information about XFP transceivers, you can visit Fiberstore.

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Owing to the pioneering discoveries and breakthrough inventions made in fiber optic technologies, fiber optic communications have transformed this world. As the result of the rapid and affordable deployment of reliable fiber optic networks, easy mobile communications and smooth video downloads have been made possible. Truthfully, fiber-optic communications have not only eliminated many previous network limitations, but also expanded the capabilities of networks far beyond previous expectations. In establishing fiber optic networks, one instrumental is essential, that is the fiber optic transceiver. So many papers and articles have been contributed to these optical transceivers from different angles and aspects, such as the classification, form factors or applications, etc..Here in this passage, several frequently asked questions about optical transceiver modules are mentioned.

Fiber optic transceiver is the combination of a transmitter and a receiver into a single module. The transmitter takes an electrical input and converts it to an optical output from a laser diode or LED. The light from the transmitter is coupled into the fiber with a connector and is transmitted through the fiber optic cable plant. The light from the end of the fiber is coupled to a receiver where a detector converts the light into an electrical signal which is then conditioned properly for use by the receiving equipment.

Almost most of the fiber optic transceivers are hot-swappable or hot-pluggable devices which can support the inserting or pulling out the module without shutting down the system or significant interruption in the operation of the system. With transceiver modules designed with hot-pluggable function, one doesn’t need to power off the device when finish the pluggable process, thus avoiding restart of some operation systems. This is a big saving in time, since in telecommunications and data transmission systems, every second matters.

Fiber optic transceivers are designed to support a wide variety of speeds in different form factors, like 1Gbit/s SFP, 10Gbit/s SFP+, 40Gbit/s QSFP+, 100Gbit/s CFP, and so on. Among these optical transceiver types, several Gigabit Ethernet (GbE) ports are discussed as follows:

1000BASE-SX—It’s a fiber optic version of the standard that operates over multi-mode fiber (MMF), using a 770 to 860nm, near infrared (NIR) light wavelength. This standard specifies the distance reach between 220m (62.5/125µm fiber with low modal bandwidth) and 550m (50/125µm fiber with high modal bandwidth). Take DEM-311GT for example, this D-Link compatible 1000BASE-SX SFP can realize 550m reach over OM2 MMF with LC duplex connector.

1000BASE-LX—It’s also a fiber optic version, but it operates over single-mode fiber (SMF), using a long wavelength (1,270-1,355nm), with distances ranging from 5km to 10km. It can also run over all common types of MMF with a maximum segment length of 550m. Cisco MGBLX1, a 1000BASE-LX SFP transceiver listed in Fiberstore is for or SMF at 1310nm wavelength, supporting 10km distance reach.

Fiber optic network is affected by such technologies: wavelength-division multiplexing (WDM) and iterations of it including dense WDM (DWDM) and coarse WDM (CWDM). They multiplex a number of optical carrier signals onto a single optical fiber by using many wavelengths, so as to expand the capacity of their networks without needing to install more cables under highways. Generally speaking, a CWDM MUX/DEMUX deals with small numbers of wavelengths, typically eight, but with large spans between wavelengths (spaced typically at around 20nm). A DWDM MUX/DEMUX deals with narrower wavelength spans (as small as 0.8nm, 0.4nm or even 0.2nm), and can accommodate 40, 80, or even 160 wavelengths. CWDM transceiver and DWDM transceiver are the transceiver modules which are combined with the CWDM or DWDM technology With these technologies, it’s possible to enlarge network capacity within optical infrastructure without the expense and delays of having to constantly rebuild networks. A big saving in cost.

DDM, also known as DOM (digital optical monitoring), stands for digital diagnostic monitoring. This function can provide component monitoring on transceiver applications in details, enabling the end user to monitor such key parameters in the performance of fiber optic transceiver as transceiver temperature, transceiver supply voltage, laser bias current transmit average optical power, and so on. In a word, this DDM feature serves as an easy way for users to check if the module is functioning correctly.

Of course, frequently asked questions about optical transceiver modules are by no means limited to what have been talked above. This text just lists four points which are more practical and useful in fiber optic projects. Fiberstore, as a professional fiber optical product supplier, offers a sea of selections of compatible fiber optic transceivers with major brands which cover Cisco (ie. MGBLX1), HP, D-Link (eg. DEM-311GT) and so on. All are compatibility- and quality-assured to meet various services needs. Have any questions about or requests for fiber optic transceivers, welcome to visit Fiberstore.

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As data center ages, its speeds have maintained continuous growth over the years, such as 10Mb/s, 100Mb/s, 1Gb/s, 10Gb/s. In this big data age, more and more enterprises and organizations have stepped forward with the ongoing transition from the previous 10GbE networks to 40GbE networks, or beyond. And the big increase in network servers for data storage has led to the growing demand for high-density cabling systems. As such, push-pull patch cords, a new type of fiber optic patch cord, are designed for high density cabling, which allows for improved accessibility and reduced installation costs, an ideal solution for the high density patching environments. Maybe you have few ideas about these push-pull patch cords, and just hear the name. Don’t worry. This article is gonna give the detailed description about them.

AS we all known that it’s necessary to plug fiber patch cables from the patch panels, switches or cassettes in the data center cabling system. However, this plugging becomes increasingly harder especially in those 40/100GbE networks, since the fiber counts are increased to support such high data rates. Finger access to every patch cable becomes difficult.

For fiber patch cords with LC connectors, it’s a little tricky because this connector type is usually locked in the port with a latch on the connector body. In theory, if you want to plug out a patch cord with LC connectors, you should firstly unlock the connector from the port by clicking the latch with is with small size. Usually an additional tool is used to unplug the specific connector in a high density cabling. But in practice, network engineer could be upset about this annoying problem during cabling. To find an easy way to solve this finger access problem, patch cord with integrated push-pull tab was invented for high density cabling, known as push-pull tab patch cord (image below). It has been proven that push-pull tab can increase the cabling density by 30% to 50%, which can accommodate the future high density cabling requirements.

As mentioned above, push-pull patch cord is a new fiber patch cord type with a flexible "push/pull-tab” permitting the connector to be disengaged easily from densely loaded panels without the need for special tools. More specifically, its unique push-pull tab allows for easy finger access and a secure holding fixture for any patching or handling process. Actually, judging from construction, push-pull patch cord enjoys the same components and internal-structure as its former fiber patch cable, except for a tab attached to the connector designed for pushing or pulling the whole connector. With these special design, technicians and cabling installers can accomplish the installing and removing processes with only one hand, free from the use of additional tools.

When it comes to push-pull patch cord classification, there are mainly two versions: push-pull tab LC patch cord and push-pull tab MPO patch cord (figure shown below). LC-HD TAB and MPO-HD TAB are designed for the switchable & movable LC connector and MPO connector, respectively, allowing easy and simple management of high density fiber patch cords.

Why users choose push-pull patch cords for data center cabling? The above mentioned finger access is definitely not the only reason. The following lists other advantages.

• Easier Operation

For fiber patch cords, the duplex latch of which often sits underneath the base of the connector above, inserting and disconnecting them can be a little difficult. With push-pull patch cords, whose latch is extended out to the space in front of the connector, pull and disengage the patch cord with push-pull tab is easier. In a word, the use of push-pull patch cord increases operational accessibility.

• Increased Flexibility & Adjustability

Push-pull patch cords are designed in various specifications, able to connect different generation of devices from 10Gb/s to 40Gbp/s or beyond. They offer safe and easy pushing and pulling of the specific connector without affecting the other connectors around it.

• Less Space & Lower Cost

Besides, this high-density cabling solution provides easy installation of fiber patch cords, helping to save time and leading to a low initial investment cost accordingly. A high return on investment.

Push-pull patch cords ensures more operational accessibility, less installation or removing time and expenses, providing exceptional finger access even in the highest density environments. Fiberstore supplies many high-quality and low-cost push-pull patch cables with LC-HD TAB and MPO-HD TAB. These push-pull tab LC patch cables and push-pull tab MPO patch cables are all quality-assured to allow for smooth and high-density connections between network equipment in the rooms. For more information about push-pull patch cables, you can visit Fiberstore.

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