Category: Fiber Transceivers

SFP optical module is a compact optical transceiver module used in communication field. SFP optical transceivers are designed to support SONET/SDH, Fast Ethernet, Gigabit Ethernet, Fibre Channel and other communications standards. It interfaces a network device motherboard (switch, router, media converter or similar device) to a Fiber Channel or Gigabit Ethernet optical fiber cable at the other end. SFP transceivers are available in a wide range of data rates including 155M, 622M, 1.25G and 2.5G, which allows users to choose the most suitable transceiver for each link. Today’s article will illustrate the most popular 1.25G SFP transceivers.

Description of SFP Transceiver

SFP modules can be divided into different types according to different standard. Here is what you need to know about SFP modules. The transmission distance of a SFP is up to 120km for single-mode and 2km for multimode fiber. The SFP fiber transceiver could be dual fibers with LC connectors, or single fiber with LC or SC connectors. The wavelengths could be 850nm, 1310nm and 1550nm. The 1.25G SFP optical transceiver modules are available in different standard such as 1000BASE-T, 1000BASE-SX, 1000BASE-LX/LH, etc. The following part explains such types.

1000BASE-SX SFP Transceiver

1000BASE-SX SFP transceiver is a cost effective 850nm module supporting dual data-rate of 1.25Gbps/1.0625Gbps. It is compatible with the IEEE 802.3z 1000BASE-SX standard and operates multimode fibers link up to 550 m. The fiber optic transceiver consists of three sections: a VCSEL laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. This SFP type (e.g. J4858B) is usually applied for Fiber Channel links, Gigabit Ethernet links, Fast Ethernet links, etc. J4858B (see in Figure 1) is HP 1000BASE-SX SFP that is widely welcomed by overall users.

1000BASE-LX/LH SFP Transceiver

1000BASE-LX/LH SFP transceiver is a high performance 1310nm transceiver for single-mode fibers. It is compatible with the IEEE 802.3z 1000BASE-LX standard and also supports dual data-rate of 1.25 Gbps/1.0625 Gbps with a transmission distance of 10 /15 /20 km. Cisco GLC-LX-SM-RGD (shown in Figure 2) is 1000BASE-LX/LH SFP that can operate on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers. HP J4860C is a 1000BASE-LH SFP that can operates over 1550nm for a distance of 70km. Unlike Cisco GLC-LX-SM-RGD SFP, J4860C can support a much longer distance of 70km, which is ideal for long-haul network application.

10/100/1000BASE-T SFP Transceiver

10/100/1000BASE-T SFP Transceiver is compatible with the Gigabit Ethernet standard as specified in IEEE STD 802.3. It supports data rates of 10/100/1000 Mbps, fully satisfying 10/100/10001000BASE-T applications such as LAN 10/100/1000Base-T Fiber Channel links, Gigabit Ethernet over Cat 5 Cable, Switch to Switch Interface, Router/Server interface, etc.

Why Choose Compatible SFP Module

We have introduced several SFP modules above including the HP SFPs. The original SFP optical transceivers are very expensive, the simple solution to this is to find a reliable OEM vendor. Besides saving cost, there are many others reasons that you should choose to purchase a compatible SFP, SFP+ or XFP fiber optic transceiver. For example in a scenario where gigabit speed is required to run across a point-to-point link, the distance between the link length is assessed and an appropriate SFP transceiver module native to the host device is chosen. If a HP platform was in situation, then the selection of module will be limited by among the following: 550 meter (J4858B), 10km (J4859B), 40km (JD061A) or the maximum 70km (J4860C). Using a compatible SFP you can choose from a variety of distance limits from 550meters up to 100km in numerous increments with distances of 160km being achievable on the top product lines.

Another advantage of use compatible SFP transceivers is the freedom to tailor the transceiver to your individual requirement. Custom serial numbers can be added both to the product label and also hard coded to the device itself. Latches can be color coded for high density link identification fiber-mart.com also provide a recoding service in China, this specific service means existing SFP’s can be adapted if the host device is to be changed. In some instances, even cross-device compatibility is quite possible.

Conclusion

Because of its high performance and small size, SFP transceiver replaces the former GBIC module and becomes the most used fiber optic transceiver module in the telecommunication industry. Currently, many optical vendors supply optical transceiver modules. fiber-mart.com, as a professional telecom manufacturer and supplier, offers a full range of SFP optical transceivers that are 100% compatible with large brands. We are committed to provide high-quality products and long-term customer services to our customers. Any interested in our products, you can contact us directly.

Using standard transceivers and cables is the most straightforward way to upgrade to 100G traffic. However, there are several types of 100G optics (transceivers and cables) available on the market like the CFP, CFP2, CFP4 and QSFP28 fiber optic assemblies. QSFP28 transceivers offer the cost-optimized solutions for connecting 100G switches together in a rack or data center, which become very popular in the 100G connectivity. Today, we are going to introduce this smallest 100G form factor transceiver—QSFP28 to you.

QSFP28 Optical Transceivers

It is notable that QSFP28 transceiver not only have the same physical size as the QSFP+ used for 40G traffic, but the lowest power consumption among those that are capable of handling 100G traffic. The QSFP28 interconnect offers four channels of high-speed differential signals with data rates ranging from 25 Gbps up to potentially 40 Gbps, and will meet 100 Gbps Ethernet and 100 Gbps 4X InfiniBand Enhanced Data Rate (EDR) requirements. There are basically two types of QSFP28 transceivers seen in the below image.

QSFP28-SR4 transceivers is specially designed to support connections of up to 100 meters over multimode fiber. This approach is similar to using AOC cables, but here it is possible to use structured cabling. They use more expensive non-standard MPO (multi push-on/pull-off cable) connectors which cancel out some of the cost savings of the transceiver. QSFP28-LR4 versions support connections up to 10km over single-mode fiber. They use standard LC connectors and the existing structured LC cabling.

For distances longer than 10km, there have also been some recent breakthroughs in transceivers with DWDM capabilities, most significantly the PAM4. To be effective, however, the DWDM QSFP28 PAM4 requires amplification for even very short distances, and for any distance over 5 or 6km, needs dispersion compensation. With this, it can handle data traffic up to 80km.

QSFP28 Cable Assemblies

Compared to the QSFP28 transceivers, QSFP28 cable (DAC or AOC cables) is the more convenient, low-cost method of connecting 100G equipment. And most importantly, using a single cable assembly removes many of the problems associated with dirty connectors. DAC is suitable for applications within 15m and AOC up to 70m. AOC cable assemblies provide similar performance to discrete transceivers and fiber cables. The following image shows a QSFP28 AOC (left) and QSFP28 DAC cables (right).

QSFP28 Application

No matter you choose to use the QSFP28 transceivers or cables, they are indeed the ideal solution for switch vendors who need to handle data that stays within the rack and the data center. QSFP28 offers the perfect fit for these scenarios. However, for the 100G longer distance, the CFP and CFP2 offer DWDM Coherent technology and enable multi-channel long distance connectivity of more than 1000km. One thing we can’t miss is that the CFP is too big to be used in an Ethernet switch in volume.

Even though a vendor chooses the smaller CFP2 or CFP4, the size and power are often unrealistically high. One solution is to offer CFP DWDM support for those few links where it’s required, but even there, the increase in power consumption and the decrease in available ports have an impact on the overall cost-effectiveness of the switch.

Conclusion

The QSFP28 fiber optic solution that offers the best of both worlds allows the user to get the full benefits of QSFP28 transceivers and cables in the datacom equipment, but also gets the advantages of high-speed traffic transportation between sites. fiber-mart.COM offers a variety of 100G modules, DACs and AOCs, as well as the cable assemblies and management hardware which can satisfy short or long reach applications. For more detailed information, please contact us directly.

Data center regularly went through great migration from 1G, 10G to 40G, 100G over the past few decade. Since IEEE 802.3ba standard defined the 40G Ethernet on June 17, 2010. The newest widely adopted optical transceivers is the QSFP+ that offers aggregated optical speeds of 40G. There are many variants for QSFP+ small from factor including LR4 (10km single-mode), IR4 (2km single-mode) or ESR4 and SR4 for short haul multi-mode. So what are they and what is the difference between them? The following passage will provide a satisfying answer to you.

QSFP optical transceivers have four separate 10G channels to simultaneously operating for supplying 40GbE network and sum up the capacity into a single channel. The following tables shows QSFP40G portfolio, of which 40GBASE-SR4, 40GBASE-LR4 and 40GBASE-ER4 are the most commonly used 40G physical layers.

1. 40GBASE-SR4

40GBASE-SR4 (short range) is a port type for multi-mode fiber and uses 850nm lasers. It uses four lanes of multi-mode fiber delivering serialized data at a rate of 10.3125 Gbit/s per lane. 40GBASE-SR4 has a reach of 100m on OM3 and 150m on OM4. There is a longer range variant 40GBASE-ESR4 with a reach of 300m on OM3 and 400m on OM4. This extended reach is equivalent to the reach of 10GBASE-SR. Take JG325A (see in Figure 2) as an example, it is HP compatible 40GBASE-SR4 QSFP+ transceiver. It primarily enables high-bandwidth 40G optical links terminated with MPO multi-fiber connectors and can also be used in a 4x10G module for interoperability with 10GBASE-SR interfaces.

2. 40GBASE-ER4

40GBASE-ER4 (extended range) is a port type for single-mode fiber being defined in P802.3bm and uses 1300nm lasers. It uses four wavelengths delivering serialized data at a rate of 10.3125 Gbit/s per wavelength.

3. 40GBASE-LR4

40GBASE-LR4 (long range) is a port type for single-mode fiber and uses 1300nm lasers. It uses four wavelengths delivering serialized data at a rate of 10.3125 Gbit/s per wavelength. Take FTL4C1QE1C as an example, it is Finisar FTL4C1QE1C  (see in Figure 3) compatible 40GBASE-LR4 QSFP+ transceiver supporting link lengths of 10km at a wavelength of 1310nm.

Comparison of These Three 40GBASE Standards

Through the above definitions of each type of 40G physical layers, you may have a further understanding of them. Now, we are comparing them one by one. 40GBASE-SR4 is for multi-mode fiber while 40GBASE-LR4 and 40GBASE-ER4 is a port type for single-mode fiber. The multi-mode solutions require special MPO fiber ribbons (multi-strand optical cables) to transport the 4 different 10G optical connections. Single-mode solutions use only two strands of fiber and combine the 4 channels using inexpensive CWDM technology. This gives a tremendous advantage, simplifying the connectivity to standard LC optical connectors and thus reducing costs further.

In addition, 40GBASE-LR4 QSFP+ transceivers are most commonly deployed between data-center or IXP sites with single mode fiber. 40GBASE-SR4 QSFP+ transceivers are used in data centers to interconnect two Ethernet switches with 12 lane ribbon OM3/OM4 cables. And from the above figure, we can know that they support different transmission distance in different wavelengths and with different connectors.

Summary

To sum up, 40GBASE-SR4, 40GBASE-LR4 and 40GBASE-ER4 are distinguished with each other in several different features—wavelength, connector, transmission distance, etc. fiber-mart.com offers a wide variety of high-density and low-power 40GBASE QSFP+ transceiver modules. They are the best-selling products of our company for its large stocks, competitive price and high quality. In addition, there are also a promotion for MTP cables. For more information, please contact us directly.

Are you turning to deploying single-mode cables to speed up your infrastructure? If yes, let’s say you have made the right choice. In general, single-mode cables are typically categorized into OS1 and OS2 single-mode fibers. Besides this, a variety of SM optical fibers with carefully optimized characteristics are also available in ITU-T G.652, 653, 654, 655, 656 or 657 standard. Each has its unique specification, which reflects the evolution of transmission system technology from the earliest installation of single-mode optical fiber to the present day. Today’s article will make a brief introduction to the G.65x series of single mode fiber patch cables so as to assist you in making a wise selection.

G.652—The ITU-T G.652 fiber is the most commonly deployed single-mode fiber. This standard SM fiber comes in four variants (A, B, C, D) see in Figure 2. A and B have a water peak. C and D eliminate the water peak for full spectrum operation. The G.652.A and G.652.B fibers are designed to have a zero-dispersion wavelength near 1310 nm, therefore they are optimized for operation in the 1310nm band. The more recent variants (G.652.C and G.652.D) feature a reduced water peak that allows them to be used in the wavelength region between 1310 nm and 1550 nm supporting Coarse Wavelength Division Multiplexed (CWDM) transmission.

G.653—G.653 fiber is also called dispersion-shifted fiber (DSF). Compared with G.652, G.653 has a reduced core size, which is optimized for long-haul single-mode transmission systems using erbium-doped fiber amplifiers (EDFA). And the wavelength of zero chromatic dispersion was shifted up to 1550 nm. One of the most troublesome, four-wave mixing (FWM), occurs in a Dense Wavelength Division Multiplexed (CWDM) system with zero chromatic dispersion, causing unacceptable crosstalk and interference between channels.

G.654—G.654 fiber can handle higher power levels between 1500 nm and 1600 nm, which is mainly designed for extended long-haul undersea applications. It uses a larger core size made from pure silica to achieve the same long-haul performance with low attenuation in the 1550nm band. This G.654 specifications entitled “characteristics of a cut-off shifted single-mode optical fiber and cable.”

G.655—G.655 is known as non-zero dispersion-shifted fiber (NZDSF). It has a small, controlled amount of chromatic dispersion in the C-band (1530-1560 nm), where amplifiers work best, and has a larger core area than G.653 fiber. G.655 fiber overcomes problems associated with four-wave mixing and other nonlinear effects by moving the zero-dispersion wavelength outside the 1550nm operating window. There are two types of NZDSF, known as (-D)NZDSF and (+D)NZDSF. They have respectively a negative and positive slope versus wavelength. G.655 fibers were mainly used to support long-haul systems that use DWDM transmission.

G.656—The G.656 fiber is also called Medium Dispersion Fiber (MDF). It is designed for local access and long haul fiber that performs well at 1460 nm and 1625 nm. This kind of fiber was developed to support long-haul systems that use CWDM and DWDM transmission over the specified wavelength range. And at the same time, it allow the easier deployment of CWDM in metropolitan areas, and increase the capacity of fiber in DWDM systems.

G.657—G.657 optical fibers are intended to be compatible with the G.652 optical fibers but have differing bend sensitivity performance. It is designed to allow fibers to bend, without affecting performance. This is achieved through an optical trench that reflects stray light back into the core, rather than it being lost in the cladding, enabling greater bending of the fiber. G.657 as the latest standard for FTTH applications, along with G.652 is the most commonly used in last drop fiber networks.

Summary

In the above context, the passage has briefly weighted up G.652, G.653, G.654, G.655 and G.657 single-mode fibers. Note that G.657A is essentially a more expressive version of G.652D, with a superior bending loss performance and should you start feeling a little benevolent towards deploying it on a long-haul application. I can immediately confirm that this allows for a glimpse into the workings of silliness. Dispersion Shifted Fiber (DSF) in accordance with G.653 has no chromatic dispersion at 1550 nm. However, they are limited to single-wavelength operation due to non-linear four-wave mixing. G.654 compliant fibers were developed specifically for undersea un-regenerated systems.

Choosing the right single-mode fiber for your network application is a critical decision. fiber-mart.com single-mode optical cables provide the cost-effective combination of high-bandwidth performance and increased reliability. Our single-mode fibers are available in various types of connectors like the LC LC single mode patch cord, and can be utilized in many applications. For more detailed information about single-mode fiber patch cables, you can contact us.

When deploying a fiber network, people nowadays not only appreciate the high-speed broadband services, but the maintenance of how long it will last. After all, optical fiber is a particular type of hair-thin glass with a typical tensile strength that is less than half that of copper. Even though the fiber looks fragile and brittle, but if correctly processed, tested and used, it has proven to be immensely durable. With this in mind, there are essentially factors that will affect the longevity of your fiber network.

Installation Strains

Stress, on the other hand, is a major enemy of fiber longevity, so the protection task is passed to the cable installer, who will ensure that the use of suitable strength elements limits the stress applied to the cable to much less than the 1 per cent proof test level. The installer then needs to ensure that the deployment process does not overstrain the cable. Figure 2 below illustrates a typical crew deployment for a trunk installation. The whole process should be paid more attention to the stress.

Of the three techniques commonly used—pulling, pushing and blowing, only pulling creates undesirable stretching (tensile stress). Unlike metal, glass does not suffer fatigue by being compressed, and so the mild compression caused during pushing causes no harm to the fiber.

Surface Flaws

Optical fiber typically consists of a silica-based core and cladding surrounded by one or two layers of polymeric material (see in Figure 3). Pristine silica glass that is free of defects is immensely resistant to degradation. However, all commercially produced optical fibers have surface flaws (small micro-cracks) that reduce the material’s longevity under certain conditions. The distribution of flaws on the surface of the silica-based portion of the fiber largely controls the mechanical strength of the fiber. fiber-mart.COM fiber optic cables are well tested to ensure less surface flaws, like LC to ST fiber cable.

To conquer this, reputable fiber suppliers carry out proof testing, which stretches the fiber to a pre-set level (normally 1 per cent) for a specified duration to deliberately break the larger flaws. And the user is then left with a fiber containing fewer, smaller flaws that need to be protected from unnecessary degradation. This means primarily stopping the creation of new flaws by coating the fiber with a protective and durable material for its primary coating.

Environmental Factors

Once deployed, the local environment has a big impact on fiber life. Elevated temperatures can accelerate crack growth, but it is the presence of water that has been historically of most concern. The growth of cracks under stress is facilitated by water leading to “stress corrosion”.

You can check what the tendency of a fiber to suffer stress corrosion is by reviewing its “stress corrosion susceptibility parameter”, much more conveniently referred to as “n”. A high n value (around 20) suggests a durable fiber and coating.

Calculating How Long Your Network Will Last

Bearing in mind the three factors above, how can you calculate the lifetime of your fiber network? In general, the chances of a fiber being damaged by manual intervention, such as digging, over the same time frame is about 1 in 1,000. Quality fiber, installed by benign techniques and by careful installers in acceptable conditions should, therefore, be extremely reliable – provided it is not disturbed.

It is also worth pointing out that cable lengths themselves have rarely failed intrinsically, but there have been failures at joints where the cable and joint type are not well matched, allowing the fibers to move – for example, due to temperature changes. This leads to over stress of the fiber and eventual fracture.

Conclusion

To tell the truth, the biggest enemies to the carefully engineered reliability of fiber jumper can be either humans or animals, rather than the fused silica itself. The provided fibers are stored and coiled correctly, it is quite possible that they turn out to be stronger than we at first thought and perhaps the original flaws begin to heal with time and exposure to water under low stress levels. fiber-mart.COM offers high quality fiber cable assemblies such as Patch Cords, Pigtails, MCPs, Breakout Cables etc. All of our products are well tested before shipment. If you are interested, you can have a look at it.

Fiber optic cable is considered as one of the most effective transmission medium today for safe, and long-reach communications, and it also offers a number of advantages over copper. In general, fiber optic cable consists of a core, cladding, coating, strengthening fibers, and a cable jacket, which has been clearly introduced in the previous article. Today’s article will focus on the several materials in fiber optic cable construction, as well as their features and applications.

PVC (Polyvinyl Chloride)

Polyvinyl Chloride (PVC) is one of the most commonly used thermoplastic polymers in the world. The PVC cable is typically used for patch connections in the data center, wiring closet, and at the desktop. PVC is produced in two general forms, first as a rigid or unplasticized polymer (RPVC or uPVC). The following image shows a ST single-mode pre-Terminated cable (0.9mm PVC Jacket).

Features:

Good resistance to environmental effects. Some formulations are rated for -55 to +55.

Good flame retardant properties. Can be used for both outdoor and indoor fiber optic cables.

PVC is less flexible than PE (Polyethylene).

PE (Polyethylene)

Polyethylene is a kind of polymer that commonly categorized into one of several major compounds of which the most common include LDPE, LLDPE, HDPE, and Ultrahigh Molecular Weight Polypropylene. Polyethylene fiber has a round cross section and has a smooth surface. Fibers made from low molecular weight polyethylene have a grease like handle.

Features:

Popular cable jacket material for outdoor fiber cables

Very good moisture and weather resistance properties

Very good insulator

Can be very stiff in colder temperatures

If treated with proper chemicals, PE can be flame retardant.

Kevlar (Aramid Yarn)

The word Aramid is a generic term for a manufactured fiber in which the fiber forming substance is a long chain synthetic polyamide in which at least 85% of the amide linkages are attached directly to the two aromatic rings as defined by the U.S. federal trade commission. Kevlar fiber is based on poly (P-phenylene terephthalamide). Aramid yarn is the yellow fiber type material found inside cable jacket surrounding the fibers. It can also be used as central strength members.

Features:

Aramid yarn is very strong and is used in bundle to protect the fibers.

Kevlar is a brand of aramid yarn. Kevlar is often used as the central strength member on fiber cables which must withstand high pulling tension during installation.

When Kevlar is placed surrounding the entire cable interior, it provides additional protection for the fibers from the environment.

Steel Armor

The steel armored fiber cable, using light-steel tube, can provide maximum bend radius, strong protection and flexible cabling. Steel armor jacket is often used on direct burial outdoor cables and it provides excellent crush resistance and is truly rodent-proof. Since steel is a conductor, steel armored cables have to be properly grounded and loss fiber optic cable’s dielectric advantage. Armored fiber optic cable are often used in the outdoor direct burial cables and for the industrial environment where cables are installed without conduits or cable tray protection. The following image shows a single-mode armored fiber optic cable.

Various types of these light-steel armored fiber cables are in stock in fiber-mart.COM, including pre-terminated armored fiber patch cables, armored fiber trunk cables and field-terminated armored fiber cables for both indoor and outdoor applications.

Features:

Provides excellent crush resistance for outdoor direct burial cables

Protects cables from rodent biting

Decreases water ingress into the fiber which prolongs the fiber cable’s life expectancy

Central Strength Member

Strength member is used to increase the tensile force that will be applied on the cable during installation. Strength member will take the pulling force and will keep the fibers safe during installation. For large fiber count cables, a central strength member is often used.

The central strength member provides strength and support to the cable. During fiber optic cable installation, pulling eyes should always be attached to the central strength member and never to the fibers. On fiber splice enclosure and patch panel installations, the cable central strength member should be attached to the strength member anchor on the enclosure or patch panel.

Conclusion

When you choose to use which type of the fiber optic cables, the fiber optic cable construction, along with the mechanical and environment requirements should all be taken into account. All the above materials in the fiber optic cable construction are specifically required to meet the network infrastructure. fiber-mart.COM fiber optic cables come in various types with detailed specifications displayed for your convenient. These quality cables are designed with best-in-class performance. For more information about fiber optic cables or patch cords, you can visit fiber-mart.com.