Månadsvis arkiv: July 2016
In optical communication networks, optical transceivers are some of the most fundamental pieces of hardware for a smooth network. Nowadays, as telecommunication market is surrounded by a sea of fiber optic transceivers of different brands, originals or third-party ones, users are met with many choices. But since many name-brand networking companies charge too much for their transceivers, in most cases, users often buy smart, plug-and-play, and hot-swappable compatible transceiver modules to save money. For instance, if you’re in need of 10GBASE-LR SFP+ for your HP networking, you can turn to Fiberstore for 100% HP compatible SFP+ transceivers (JD094B) which deliver the same value and costs you only a few, US$ 48.00.
Most people often hear such a question: Will I be able to use the existing equipment with the new wiring? The answer is certainly yes. Actually, a third-party fiber optic transceiver is fully compatible with name-brand hardware. There’s simply no difference between good quality third-party ones and the original ones. In this article, I will list several reasons why you should choose HP compatible transceivers, including the compatibility, cost, and support.
One thing that a lot of people don’t really realize about optical networking equipment is that there are only a host of factories in the world which are certified to produce it. As a matter of fact, anyone who supplies top-grade optical transceivers is getting them from the same few vendors. And Fiberstore uses them too.
HP compatible SFP+ transceivers are fully MSA-compliant, so they adhere to all relevant standards for optical equipment. Take JD094B for example, this HP compatible 10GBASE-LR SFP+ works at a wavelength of 1550nm over single-mode fibers (SMFs), with a maximum link length at 40km. All these performances are just the same as what can be expected from the original HP SFP+ transceiver. Neither your HP networking will detect the difference, nor you can tell the difference, since the only difference lies in the name on the package.
Some companies use the exact same ODMs (original design manufacturers) that the major switch OEMs (original equipment manufacturers) use. However, since optical transceivers are the primary business for some third-party transceiver companies, they may understand which ODMs provide the highest quality part for a given data rate or transport protocol. It is not inconceivable for some third-party optics companies to provide more reliable components than those offered by the major switch OEM companies.
The lower costs of third-party optics really cannot be overstated. Typically third-party transceivers cost substantially less than name brands. Why you pay hundreds of dollars for a device that only cost much less, say dozens dollars from third-party? In many cases, a full loadout of third-party transceivers can shave so much money off of an upgrade budget to fund entirely new pieces of hardware. Or they can put a piece of equipment within range, which wouldn’t have been if name-brand ports had to be purchased. There’s no compelling reason to over-pay for the name brand optics.
By definition third-party providers of optical transceivers are not tied to a specific switch or router platform. Therefore, their optics will typically interoperate across multiple platforms. This means one specific inventoried part number can be used in both a HP switch and a Cisco switch, as an example. Thus, this approach effectively reduces sparing inventory as well as the operational headaches associated with maintaining inventories for each switch platform.
Since selling transceivers is the primary business for most third-party transceiver companies, most strive for immediate availability of product. Fiberstore keeps a full stock of our transceivers in-house and ready to ship. There is no complicated ordering process, and once you’ve made an order, you don’t have to wait days or weeks for the items to be delivered. Usually, the products are shipped the same day when you place an order.
HP compatible SFP+ transceivers are cheaper, 100% compatible and in large stock. Whether you need 10GBASE-LR，10GBASE-ER ports, or 10BASE-SR, Fiberstore can meet your needs rapidly for lower prices, no waiting. Certainly, HP compatible SFP optics are also available here, like HP J4858C. For more information about HP compatible transceivers, you can visit Fiberstore directly.
It’s true that fiber optic cable, based on optical technology to carry information between two points, have become increasingly important in fiber optic systems. This cable is often attached with the same or different connectors on the ends to connect devices, for example, LC LC multimode patch cord (LCs on both ends). When used in premises, fiber optic cables can be used as backbone cabling in a standard structured cabling network, connecting network hardware in the computer room. And when applied in optimized fiber optic networks, they go directly to the work area with only passive connections in the links. They can be installed indoors or outdoors using several different installation processes. One of my recent blogs has talked about safety issues about fiber optic cable installation. Today, this article still focuses on its installation, but from other aspects, including the general guidelines, its pulling tension, bend radius, and so on.
When deployed outside, fiber optic cables may be direct buried, pulled or blown into conduit or innerduct, or installed aerially between poles. When used outside, they can be e installed in raceways, cable trays, placed in hangers, pulled into conduit or innerduct or blown though special ducts with compressed gas. The installation process depends on the nature of the installation and the type of cables being used.
First point to mention is that fiber optic cable is often custom-designed for the installation and the manufacturer may have specific instructions on its installation. So, it’s highly recommended to follow the cable manufacturer’s suggestions. Often, it’s necessary to check the cable length to make sure the cable being pulled is long enough for the run, so as to prevent having to splice fiber and provide special protection for the splices. Of course, it’s better to try to complete the installation in one pull. Prior to any installation, one should assess the route carefully to determine the methods of installation and obstacles that are likely to be encountered.
- Pulling Tension
Fiber optic cable is designed to be pulled with much greater force than copper wire if pulled correctly, but excess stress may harm the fibers, potentially causing eventual failure. Cable manufacturers install special strength members, usually aramid yarn, for pulling. Fiber optic cable should only be pulled by these strength members. Any other method may put stress on the fibers and harm them. During installation, swivel pulling eyes should be used to attach the pulling rope or tape to the cable to prevent cable twisting during the pull.
Besides, cables should not be pulled by the jacket unless it is specifically approved by the cable manufacturers and an approved cable grip is used. Tight buffer cable can be pulled by the jacket in premises applications if a large (~40 cm, 8 in.) spool is used as a pulling mandrel. It’s right to wrap the cable around the spool 5 times and hold gently when pulling.
It’s ill-advised to exceed the maximum pulling tension rating. It’s suggested to consult the cable manufacturer and suppliers of conduit, innerduct, and cable lubricants for guidelines on tension ratings and lubricant use.
On long runs (up to approximately 3 miles or 5 kilometers), one should use proper lubricants and make sure they are compatible with the cable jacket. If possible, an automated puller can be used with tension control and/or a breakaway pulling eye. On very long runs (farther than approximately 2.5 miles or 4 kilometers), one should pull from the middle out to both ends or use an automated fiber puller at intermediate point(s) for a continuous pull.
- Bend Radius
When there are no specific recommendations from the cable manufacturer, the cable should not be pulled over a bend radius smaller than twenty (20) times the cable diameter. And after completion of the pull, the cable should not have any bend radius smaller than ten times the cable diameter.
- Twisting cable
It’s known that twisting the cable can stress the fibers, thus in no case should one twist the cable. (Tension on the cable and pulling ropes can cause twisting.)
Use a swivel pulling eye to connect the pull rope to the cable to prevent pulling tension causing twisting forces on the cable.
Roll the cable off the spool instead of spinning it off the spool end to prevent putting a twist in the cable for every turn on the spool.
When laying cable out for a long pull, use a “figure 8” on the ground to prevent twisting. The figure 8 puts a half twist in on one side of the 8 and takes it out on the other, preventing twists.
Fiber optic cables have been widely deployed for computer net- works (LANs), closed circuit TV (video), voice links (telephone, intercom, audio), building management, security or fire alarm systems, or any other communications link. With its installation in large scale, it’s of great importance to know some basic points on cable installation discussed in this text. As for the fiber optic cables chosen for project, you can try Fiberstore, whose cables are available in many types, like SC fiber optic cable, LC SC cable, MTP cable. All are test- and quality-assured, suitable for both indoor and outdoor installation.
It’s known that fiber optic termination methods vary based on the types of fiber optic cable being terminated, the style of connectors or splices used and the termination process appropriate for that connector. Generally speaking, fiber optic cable can be terminated in two ways—connectors that mate two fibers to create a temporary joint and/or connect the fiber to network equipment, and splices which create a permanent joint between the two fibers. Each termination method must have two primary characteristics: good optical performance (low loss and minimal reflectance) and high mechanical strength. As such, the terminations can be made in the right style, installed in a manner that provides low light loss and back reflection and protected against the expected environment, dirt or damage while in use. This passage mainly talks about the first method: connector.
Most fiber optic connectors are plugs or so-called male connectors with a protruding ferrule that holds the fibers and aligns two fibers for mating. Choosing a connector type for any installation should consider if the connector is compatible with the systems planned to utilize the fiber optic cable plant, if the termination process is familiar to the installer and if the connector is acceptable to the customer. If the systems are not yet specified, patch cords with different connectors on each end (e.g. LC ST patch cable) may be necessary.
Fiber optic connectors are manufactured in different styles (say, ST, SC, LC, MT-RJ) that attach to the fibers in a fiber optic cable (LC to LC fiber cable single mode) by a number of methods, such as epoxy polish, prepolished/splice, etc.. ST is one of the most popular connectors for multimode networks, like most buildings and campuses. SC is a snap-in connector that is widely used in singlemode systems for it’s excellent performance and multimode systems because it was the first connector chosen as the standard connector for TIA-568. LC uses a 1.25 mm ferrule, half the size of the ST. Otherwise, it’s a standard ceramic ferrule connector, easily terminated with any adhesive. MT-RJ is a duplex connector with both fibers in a single polymer ferrule. It uses pins for alignment and has male and female versions, basically obsolete nowadays.
Several termination methods are available for fiber optic cables, and the following passages list three terminations: adhesive termination, crimp/polish termination and prepolished termination.
- Adhesive Termination
Epoxy Polish: The fiber is glued into the connector with two-part epoxy and the end polished with special polishing film. This method provides the most reliable connection and lowest losses. The epoxy can be allowed to set overnight or cured in a special oven. A “heat gun” should not be used to cure the epoxy as the uneven heat may not cure all the epoxy or may overheat it which will prevent curing.
Hot Melt: This connector is similar to the epoxy/polish connector but already has the adhesive (a heat set glue) inside the connector. The adhesive is liquefied in an oven before the fiber can be inserted. The fiber is secured when the adhesive cools.
Anaerobic Adhesives: These connectors use a quick-setting adhesive instead of the epoxy. They may use a single part adhesive or an adhesive and set- ting agent. Some adhesives do not have the wide temperature range of epoxies, so they should only be used indoors unless otherwise specified.
- Crimp/Polish Termination
These connectors use a crimp on the fiber to hold it in the connector ferrule. The fiber can be polished like an adhesive connector or cleaved with a special tool. Insure the crimp is made properly to prevent fiber pistoning (pulling back or pushing forward in the connector ferrule.)
- Prepolished Termination
These connectors have a short stub of fiber already epoxied into the ferrule and polished. Termination requires cleaving a fiber, inserting it into the back of the connector like a splice and crimping. The loss of these connectors will generally be higher than adhesive connectors, since they include the connector loss plus a splice loss in every connector.
To ensure low loss, the fiber must be cleaved properly, which requires a good cleaver and good technique. Insure the crimp is made properly to prevent fiber pistoning. The termination process can be monitored with a visual fault locator.
Connectors can be installed directly on most cable types, including jacketed tight buffer types like simplex, zipcord and breakout cables, where the where the aramid fiber strength members in the cable are crimped or glued to the connector body to create a strong connector. Connectors can be attached to the 900 micron buffered fibers in distribution cables, but the termination is not as rugged as those made to jacketed cables, so they should be placed in patch panels or boxes for protection. The 250 micron buffered fibers in loose tube cables cannot be easily terminated unless they have a reinforcement called a breakout kit or furcation kit installed, where each fiber is covered by a larger plastic tube. Generally loose tube and ribbon cables are terminated by splicing on a terminated pigtail.
Cables can be pulled with connectors already on them if, and a big if, you can deal with two issues: First, the length must be precise. Too short and you have to pull another longer one (it’s not cost effective to splice), too long and you waste money and have to store the extra cable length. Secondly, the connectors must be protected. Some cable and connector manufacturers offer protective sleeves to cover the connectors, but you must still be much more careful in pulling cables. You might consider terminating one end and pulling the unterminated end to not risk the connectors.
When special tools are required, use them in the appropriate manner. And once installation is completed, connectors should be covered with an appropriate dust cap and stored in a safe location awaiting testing or connection to net- work equipment.
Fiber terminations must also be of the right style to be compatible to the equipment involved and be protected against the environment in which they are installed. When several connector types are all acceptable, or only one connector type is available but not ideal for the installation, the installer should discuss the merits of other types before committing to the project.
A common problem facing cabling installers during installation or other fiber handling is the light losses or weaker optical signal, which is cause by the fact that when a fiber bend radius exceeds the specified figure, the angle at which the light hits the cladding changes and some light will escape and result in power loss. It’s known that light losses is the commonplace found in fibers, like LC-SC multimode fiber patch cord. In 2009, bend-insensitive multi-mode fiber (BIMMF) has been introduced, which can withstand tight bends, or even kinks, or other withstand tough treatment without suffering significant light losses in many cases. It seems to be an ideal product. How much do you know about it? Have some ideas about its working principle, its compatibility, its testing issues? Follow this article and find answers.
An introduction to the working principle helps you to understand how BIMMF reduces signal losses with its bend-insensitivity and becomes the preferred choice in data center applications.
BIMMF technology prevents light from escaping. BIMMF has an innovative core design that incorporates a graded-index core profile combined with a specially engineered optical trench. A specially engineered optical trench (image below) is used to trap the light in the many modes which propagate within the fiber core. The trench, or also called moat, with low refractive index, surrounds the core in BIMMF to reflect lost light back into the core. It acts like a barrier for propagating light. Keeping the light in the core, even in the most challenging bending scenarios, significantly reduces the bend-induced. The trench is just an annular ring of lower index glass surrounding the core with very carefully designed geometry to maximize the effect.
One question with BIMMF is whether it’s compatible with conventional fibers. Can they be spliced or connected to other conventional (non-BI) fibers without problems? How does the inclusion of higher order modes affect bandwidth?
Measurement of core size, NA, differential mode delay (DMD) and bandwidth were developed prior to the introduction of BI MMF designs. These measurements are in the process of being evaluated and updated, so measurement results may depend on the manufacturer of the BIMMF. For the most part, it appears that BIMMF can be made to be compatible to other non-BI fibers by modifying the core design slightly or careful engineering of the trench surrounding the core, but at this point it is left to the manufacturers to show their product will perform equivalently to the installed base of fiber.
When short lengths of BIMMFs are measured, they may have a larger effective NA and core size than conventional MMFs since they propagate “leaky modes” that are attenuated in conventional fiber designs. This may affect splice or connector loss when mating BIMMF with conventional MMF but usually only in one direction, from BIMMF to conventional MMF, in a manner similar to the losses from mismatched fibers.
Testing BIMMFs or using them for reference cables for testing is another matter. For testing, link set ups included both all BIMMF channels and mixed links using a combination of BIMMF assemblies and standard non‐BIMMF assemblies. 10G and 40G testing used full duplex traffic with two transceivers (e.g. E10GSFPLR or QFX-QSFP-40G-SR4), and this approach is necessary, since the trunk cables contain only 12 fibers and per the standard, and full duplex traffic at 100G requires 20 fibers. The channel configurations for the various active tests are shown below.
This kind of cable has obvious advantages. In patch panels, it should not suffer from bending losses where the cables are tightly bent around the racks. In buildings, it allows fiber to be run inside molding around the ceiling or floor and around doors or windows without inducing high losses. It’s also insurance against problems caused by careless installation.
However, BIMMF profiles pose a complex design challenge. Profile parameters must be carefully selected to ensure all key attributes satisfy all relevant industry standards. Bandwidth is a key parameter for MMFs and the graded-index profile remains a key driver to achieve high bandwidth. Any deviation from the optimum profile results in reduction of bandwidth of the MMFs. Inappropriate trench location can result in delay errors of the higher-order modes, and this can significantly impair bandwidth performance. Locating the trench too far from the fiber core can result in failure to comply with fundamental industry standards. The fiber’s trench location must be carefully engineered to ensure superior bandwidth and macrobend response while maintaining industry standard requirements for core diameter, numerical aperture and chromatic dispersion.
BIMMF is fully compliant with the OM3 and OM4 standards for laser-optimized fibers, and is also backward compatible with the installed base of 50-μm MMFs. With its improved bend -sensitivity, BIMMF allows for less light losses in the stressed section of the fiber, reducing the challenges encountered in installations in local area network (LAN) data centers.
As one of the latest and most popular technologies utilized for information transmission from one point to another, the fiber optic communication has gained more and more importance in data centers nowadays. Since its introduction, fiber optic communication has revolutionized the telecommunications industry, transforming into the fiber optic broadband Internet service enjoyed by people today. With the obvious advantages, fiber optic cables have become an essential component in fiber optic communications. Terminated with connectors on ends, these cables (e.g. SC SC fiber cable) carry the light signals generated by the transmitter to the receiver. Although this fiber optic connection has been widely used in data centers because of its high data transmission speeds over long distance, fiber optics, like many other things, also has two sides: the pros and cons. Here this article delves into the advantages and disadvantages of fiber optic networks.
Great Immunity & High-quality Connections: Since the fiber core is made of glass, which is an insulator, no electric current can flow through. It’s immune to electrometric interference and radio-frequency interference (EMI/RFI), crosstalk, impedance problems, and more. More specifically, fiber optics are highly resistant to EMI and have a low rate of bit error. EMI is a disturbance caused by electromagnetic radiation from an external source. This disturbance can interrupt or degrade the performance of a conventional metallic cable connection and can be caused by an object that carries electrical currents, such as power lines or even the sun. Fiber optics are also resistant to corrosion, making them a good option for beachfront properties where copper cabling would otherwise be susceptible to degradation by salt and seawater.
Great Security: Security is a major concern for some companies, enterprises or organizations, whether small or big. With fiber optic cables, the data carried on are very safe. Fiber optics don’t radiate signals and it’s really difficult to tap or listen in the passed through information. Besides, once there occurs any physical break, it’s extremely to identify since this break will have impacts on the whole system. Fiber optic networks also enable you to put all your electronics and hardware in one central location, instead of having wiring closets with equipment throughout the building.
Scalability & Design: Fiber optics are much more scalable in nature as new equipment can be added easily and laid over the original fiber. Wavelengths can be turned on or off on demand, which allows for the easy provisioning of services and quick scaling for a growing business. Fiber optic cables are also much smaller in size and lighter weight than copper wiring. These fibers can typically be put in place in preparation for growth needs up to 15 to 20 years in the future. Although growth is often speculative, spare fibers can be included for future requirements to accommodate growth. Alternatively, additional cables can be put in place at a later time to make way for network expansion.
It’s well known that fiber optic cable provides more bandwidth than copper, and can carry more information with greater fidelity than copper wire. And no one can defy its advantages. But it’s also clear that fiber optic networks have several weak points.
Physical Damage: As mentioned above, fiber optic cable is thinner and lighter than copper wiring, so it makes for a more delicate system. Just because of its small size, fiber optic cable can be easily cut by accident during building renovations or rewiring. In addition, as fiber optic cables can transmit much more data than metallic networks, you would need fewer cables to service a larger number of people. This means that cutting just one cable could disrupt service for a large number of businesses and individuals. Additionally, wildlife also poses a threat, as the fiber cable jackets are intriguing to some species. Tunneling animals and rodents may chew through the cable, while many insects can find the cabling palatable. Anything that can wrap itself around the cable can also cut off the transmission. Fibers are also sensitive to bending, making laying fibers around corners a tricky business. Fiber optic networks are also susceptible to radiation damage or chemical exposure.
Fiber Fuse: At high power, fiber optic networks are susceptible to something known in the industry as “fiber fuse”. This occurs when too much light meets with an imperfection in the fiber, which can destroy long lengths of cable in a short amount of time.
Short-Term Large Budget: Judging from the long-term running, it’s cost-effective. But when considering for short-term use, it’s costly to implement fiber optic systems. Special test equipment is often required along with installers that have skilled knowledge about laying a fiber optic network. Fiber endpoints and connection nexuses also require special equipment and setup. In addition, it may take specialized equipment to diagnose an issue with a fiber optics network, making for higher-cost fixes if the cables sustain damage.
Although there some several weaknesses, fiber optics technology has still dominated the telecommunication market. And fiber optic network is selected as the main communication way. To ensure efficient fiber optic network, it’s important to choose the high-quality fiber optic products. Here Fiberstore is highly recommended for its reliable products, including optical transceivers (say SFP modules), fiber optic cables (SC SC fiber cable), as well as testing equipment used in cable installation, and so on. You can try it!