Category: Fiber Transceivers

Optical transceivers, Active Optic Cables, data center switches, and cable management in data centers.

Telecom Hardware: NIC, Transceiver, Modem and Media Converter

People usually have the misconception about the devices like the network interface card, transceiver, modem and media converter in telecommunications fields. Some even don’t know how to use them correctly. In fact, these devices are all possessed with different functions. For example, a network interface card connects your computer to a local data network or the internet. A transceiver is responsible for taking the digital data represented by a series of zeros and ones. Modems takes the digital zeros and ones and converts it to an analog sound. While a media converter, as the name implies, is typically used to convert one media type to the other. To have a further understanding of their performances, you can have a look at the following article.
Network Interface Card
Just as said before, a network interface card (NIC) is used to connect your computer to a local data network. It functions as a middleman between your computer and the data network by translating the computer data into electrical signals. An Ethernet NIC is an indispensable transmission medium for Ethernet network. Note that we need to choose the right networking adapter that matches the transmission medium and network architecture we are connecting to. Today, most computers come with built-in Network Adapters, and the most popular one is Ethernet NIC.
Optical Transceiver
On an Ethernet network, a transceiver is mainly use to convert the digital signal to an electrical, radio or light signal by a method of encoding scheme. This method uses the number zero and one to represent the voltage. A 0 might be represented as a zero voltage on the wire, while a 1 might be represented by a positive voltage. Through this method, optical technician can easily know the performance of the transceiver. The old transceiver is just an adapter that took digital signals from an AUI port on one end and translated those into an electrical signal using RJ45 or some other port. Besides this transceiver type, there are several new types that will be introduced in the below part.
SFP Module
SFP short for Small Form Factor Pluggable, is typically used on switches and routers to easily modify the media type used by a port. SFP module is one of the common type of optical transceivers that is gaining used today, especially for Gigabit Ethernet application. Other than the former devices with a fixed media type, the port accepts the SFP module. As a result, to change the media type, we can simply plug in a different SFP module. For example, we can get an SFP to support copper or a different specifications of fiber optic. Figure 2 shows a SFP modules connected by a LC LC single mode fiber patch cable in a switch.
GBIC
GBIC (GigaBit Interface Converter) module is an old transceiver module, which is slightly larger than an SFP but performs the same function. A GBIC is a larger-sized transceiver that fits in a port slot and is used for gigabit media including copper and fiber optic. Besides the GBIC and SFP (or mini-GBIC), we should also mention an XFP transceiver, which is similar in size to an SFP but is used for 10 Gigabit networking. Additionally, there are QSFP+ modules for 40 Gigabit Ethernet and CFP or QSFP28 for 100G infrastructure.
Modem
Optical transceiver is mainly used to achieve the conversion between electrical signals and digital signals by the encoding scheme. A modem takes the digital zeros and ones and converts it to an analog sound signal that can be carried across the telephone wires. Modem is actually an abbreviated term that means modulator & demodulator. Modulation is happening on the sending end where binary data is converted to analog waves, and Demodulation is happening on the receiving end where the analog waves are converted back to binary data. Note that there is an encoding scheme that identifies when the signal represents a 0 or a 1, and the Network Adapter must match both the architecture and the transmission medium that is used.
Media Converter
A media converter is usually used when you need to convert from one media type to another like from copper to fiber or vice versa. Supposing you had an Ethernet network that uses copper cabling but we had a server that had a fiber optic network adapter card. In this case we could use a fiber optic to Ethernet copper cable media converter. But one thing you should remember is that media converters work within the same network architecture. It means the media converter can convert from one type of Ethernet to another that uses a different transmission cable, but it is not used to convert from something such as Ethernet to a different networking standard.
In order to accomplish the process of converting from one architecture to another, it would require modifying the Frame contents to modify the Data Link layer address. Media converters operate at the Physical layer, since they simply transform the signal from one encoding scheme to another. However, media converters don’t read or modify the MAC address. The following image shows a SFP to RJ45 1000BASE Gigabit Fiber Media Converter.
Conclusion
At the end of the article, you might have a basic knowledge of the above devices. These devices are equipped with unique performances that play an important role in telecommunication fields. Equipment in telecom field must be correctly selected and mixed use of the is prohibited. Therefore, if you are not sure to how to use them, please seek advice from an expert. fiber-mart.COM is a rising and professional manufacturer. We not only offers a full selections of telecom products, but aim to provide the best services to the customers.

Cabling Guide for Cisco Nexus 9508 Switch

Due to the the ever-expanding data center consolidation, virtualization and cloud technologies, network installers feel the urge to maintain a competitive advantage of their infrastructure. Except for the performance, bandwidth and latency in datacenter cabling, management and operational agility and simplicity have also elevated themselves to the top mind of data center architects and operator. Cisco Nexus 900 series represents a familiar starting point on the journey toward a new era in software-defined network, which is announced to be the most port dense and power efficient plus fastest packet forwarder and programmable data center modular switch in the industry. This article introduces basic information of Cisco Nexus 9000 series and the cabling solutions for Nexus 9508 switch.
According to Cisco’s announcement, the Nexus 9000 Series switch is the foundation of the Cisco next generation data center solution. The Cisco Nexus 9000 Series switch contains two main branches including the Nexus 9300 series fixed switches and Nexus 9500 series modular switches. Of particular interest is the Nexus 9508 of 9500 series, which is impressive in terms of performance, power efficiency, 10/40GbE and future 100GbE port density, programming environment and orchestration attributes. The following image shows the inner structure of the Cisco Nexus 9508 switch.
Cisco Nexus 9508 can offer up to 8 line cards slots with a comprehensive selection of modular line cards in a 13RU space. There are totally three line card options available: 48 port 1/10GbE SFP+ with four 40GbE QSFP+, 48 port 1/10GBASE-T with four 40GbE QSFP+ and 36 port 40GbE QSFP+ full line rate. The 1/10GbE line cards provide 640 Gbps of line rate capacity. And the 40GbE line card is based on QSFP+ form factor. From a network design perspective, the Cisco Nexus 9508 switch can be configurable with up to 1152 10 Gigabit Ethernet or 288 40 Gigabit Ethernet ports, which is very helpful for 10GbE & 40GbE migration.
Main Features of Cisco Nexus 9508 Switch
The Cisco Nexus 9508 is a versatile data center switching platform that can host 10, 40, and future 100 Gigabit Ethernet interfaces. Other than this, the switch also has other unique features:
Predictable high performance—The switch delivers 30 Tbps of non-blocking performance with latency of less than 5 microseconds, enabling data center customers to build a robust network fabric that can scale from as few as 200 10 Gigabit Ethernet server ports to more than 200,000 10 Gigabit Ethernet server ports.
Nonblocking, high-density 1 to 10 & 10 to 40 Gigabit Ethernet transition—The Cisco Nexus 9500 platform helps organizations transition from existing 1 Gigabit Ethernet Cisco Catalyst®6500 series switches server access designs to 10 Gigabit Ethernet server access designs with the same port density. And it can also helps organizations transition from 1 and 10 Gigabit Ethernet infrastructure to 10 and 40 Gigabit Ethernet infrastructure to support the increased bandwidth demands.
Advanced optics—This switch can directly use the pluggable 40 Gigabit Ethernet QSFP+ bidirectional transceiver that enables customers to use existing 10 Gigabit Ethernet data center cabling to support 40 Gigabit Ethernet connectivity.
Highly available, scalable, and robust solution—All major components are redundant, including supervisors, system controllers, power supplies, and fan trays. The switch line cards use a mix of merchant and Cisco application-specific integrated circuits (ASICs) to produce a low-complexity, low-cost design. All buffer memory is integrated into the forwarding ASICs, avoiding the need for a large number of external memory modules.
All transceivers are pluggable to support the highest possible mean time between failure (MTBF) for the switch. What’s more, the flexible and efficient chassis design has 100% headroom for future expansion with the capability to support more bandwidth and cooling and twice the number of power supplies needed to support today’s maximum configuration.
Power efficiency—The Cisco Nexus 9500 platform is the first switch chassis designed without a midplane. Line cards and fabric modules connect directly. This design approach provides optimal front-to-back airflow and helps the switch operate using less power. In addition, all Cisco Nexus 9000 series power supplies are 80 Plus Platinum rated. The typical power consumption per 10 Gigabit Ethernet port is less than 3.5 watts (W). The typical power consumption of each 40 Gigabit Ethernet port is less than 14W.
QSFP+ Direct Attach Copper Cabling
As we all know, direct attach cables (DACs) are often used to connect two or more switches which are in the same rack or in the adjacent rack. This is done to reduce the cabling cost for which DACs are much cheaper than transceivers and fiber patch cords. The following figure shows a wiring option for a Cisco Nexus 9396 to Cisco Nexus 93128 using 40G QSFP+ to 40G QSFP+ DAC cabling assemblies.
40G QSFP+ to 4 x 10 SFP+ Interconnection
The Cisco Nexus 9508 switch can also be operated in 4×10 Gigabit Ethernet mode. If the interface is logically configured as a 4×10 Gigabit Ethernet port, then each port becomes four 10Gbqs port. This will be accomplished by using copper twinax, hydras or breakout cables. This scenario can be achieved by connecting a Cisco Nexus 9000 Series Switch to a Cisco Nexus 2232 using a QSFP+ to four SFP+ copper hydra cable assembly.
40GE QSFP SR4/CSR4 Optics Cabling Options
Multimode fiber cabling is generally preferred when the distance between Cisco Nexus 9508 switch and other switches is less than 400 meters. In this circumstance, 40G QSFP+ SR4/CSR4 transceivers and MPO interconnect cable assemblies are often used. The following scenario shows how the Cisco Nexus 9508 switch is connected to Cisco Nexus 93128 switches with 40G QSFP+ SR4/CSR4 optics and MPO cable assemblies.
40GbE Connectivity With 40G BiDi Optics
As noted before, Cisco 40G SR-BiDi QSFP can be used in Cisco Nexus 9508 switch for 40G connectivity. The 40G BiDi QSFP multiplexes two 10GbE signals into one 20GbE stream and runs two 20GbE wavelengths on the optics side, and delivers a QSFP pluggable MSA compliant electric signal to the switch module, thereby only requiring the termination of a dual LC connector as used in 10GbE optical infrastructure. The SR-BiDi QSFP enables the re-use of existing 10GbE multimode fiber cable infrastructure plus patch cables as it supports the same LC connector. The SR-BiDi QSFP eliminates the cable infrastructure upgrade requirement of today’s 40GbE, which can lower capex of cabling and switch hardware. The following image shows the Cisco Nexus 9508 switch using 40G BiDi transceiver providing a zero-cost fiber cabling upgrade path for 10GbE to 40GbE.
Cisco is offering a practical way to transition to higher speed data center networking through favorable economics. With the use of Cisco Nexus 9508 switch, designers will embrace a new programmable network platform ready for the age of software-defined networking. fiber-mart.COM provides various 40G QSFP+ transceivers and fiber optic cable for the 40G connection of Cisco Nexus 9508 switch. 10G SFP+ transceivers and MPO/MTP-LC harness fiber patch cables for the 10G SFP+ to 40G QSFP+ direct connection are also provided.

FBT vs. PLC Fiber Optic Splitters

Optical technology nowadays has made huge progress to meet the growing requirement for high-density multifiber applications in telecommunication field. Fiber optic splitter, as an indispensable equipment for fiber optic network, enables signals on an optical fiber to be distributed among two or more fibers. Optical cable splitter typically can be divided into FBT (Fused Biconical Taper) splitter and PLC (Planar Lightwave Circuit) splitter. Each type has advantages and disadvantages when deploying them in a passive optical network. This article will guide you to form a basic knowledge about fiber optic splitter, especially FBT splitter and PLC splitter.
Fiber Optic Splitter
Optical splitter, also known as a beam splitter, is based on a quartz substrate of an integrated waveguide optical power distribution device, which is used to split the fiber optic light evenly into several parts at a certain ratio. Since splitters contain no electronics nor require power, they are an integral component and widely used in most fiber optic networks. The diagram below shows how light in a single input fiber can split between four individual fibers (1×4).
Optical splitters are manufactured commonly in two types according to its working principle—FBT (Fused Biconical Taper) splitter and PLC (Planar Lightwave Circuit) splitter. Splitters can be built using a variety of single mode fiber patch cables and multimode optical fibers and with most connector types for various applications.
FBT Splitter—FBT is a traditional technology that two fibers are typically twisted and fused together while the assembly is being elongated and tapered. The fused fibers are protected by a glass substrate and then protected by a stainless steel tube, typically 3mm diameter by 54mm long. FBT splitters are widely accepted and used in passive optical networks, especially for instances where the split configuration is not more than 1×4. The slight drawback of this technology is when larger split configurations such as 1×16, 1×32 and 1×64 are needed. The following picture shows a FBT splitter with a split configuration of 1×2.
PLC splitter—A PLC splitter is a micro-optical component based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability. It is manufactured using silica glass waveguide circuits that are aligned with a V-groove fiber array chip that uses ribbon fiber. Once everything is aligned and bonded, it is then packaged inside a miniature housing. PLC Splitter has high quality performance, such as low insertion loss, low PDL (Polarization Dependent Loss), high return loss and excellent uniformity over a wide wavelength range from 1260 nm to 1620 nm and have an operating temperature -40°C to +85°C. The following picture shows a PLC splitter connected with LC LC single mode patch cord.
Advantages and Disadvantages of FBT and PLC splitters
1. FBT—Fused Biconical Splitter
FBT splitter is one of the most common splitters, which is widely accepted and used in passive networks. FBT splitter is designed for power splitting and tapping in telecommunication equipment, CATV network, and test equipment.
Advantages
The product is well-known and is easy to produce, thus reducing cost of production.
Splitter ratios can be customized.
Can work on three different operating bands (850nm, 131 Onm, and 1550nm).
Disadvantages
Restricted to its operating wavelength.
Because of errors in equality insertion loss, the maximum insertion loss will vary depending on the split and increase substantially for those splits over 1:8.
Because an exact equal ratio cannot be ensured, transmission distance can be affected.
High temperature dependent loss (TDL). The operating temperature range is 23 °F- 167 °F. Any changes in temperature can affect the insertion loss.
The larger the split, the larger the encapsulation module.
Susceptible to failure due to extreme temperatures or improper handling.
2. PLC—Planar Lightwave Circuit Splitter
PLC splitter is a hot research at home and abroad today, with a good prospect of application, which is used to distribute or combine optical signals. It is based on planar lightwave circuit technology and provides a low cost light distribution solution with small form factor and high reliability.
Advantages
Suitable for multiple operating wavelengths (1260nm–1650nm); unstinted.
Equal splitter ratios for all branches.
Compact configuration; smaller size; small occupation space.
Good stability across all ratios.
High quality; low failure rate.
Disadvantages
Complicated production process.
Costlier than the FBT splitter in the smaller ratios.
Conclusion
Similar in size and outer appearance, PLC and FBT splitters provide data and video access for business and private customers, but internally the technologies behind these types vary, thus giving service providers a possibility to choose a more appropriate solution.

Guide to Several Materials in Fiber Optic Cable Construction

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.

How to Configure RJ45 Pinout

Ethernet cable, as one of the most popular types of networking cable, is mainly utilized to interconnect two wired network devices in the home or the office. Cat 5/cat6, UTP/STP cables are some of this cable type that connects all devices to get a network up and running smoothly. Unlike the fiber jumper, this Ethernet copper cable is usually terminated with a 8P8C modular connector, which is often called RJ45 (Registered Jack). The way the RJ45 connector wired to Cat 5, 5e and 6 cables differs depending upon the type of cable required.
It is known to all that, inside the Ethernet cable, there are eight color coded wires twisted into 4 pairs of wires, which poses difficulty in effectively wiring them. So how to terminated RJ45 connectors at the end of the network cable? In fact, there are three wiring standards available on the market—straight-through cables, crossover cables and rollover cables. In order to have a better understanding of the RJ45 pinout, this article will provide some basic information about them.
Different Wiring Standards
Before starting with the discussion of cable pinout for modular jack, we often get questions as to the difference in straight-through, crossover, and rollover wiring of cables and the intended use for each type of cable. These terms describe the way the cables are wired (which pin on one end is connected to which pin on the other end). The following part shows the exact pinout schemes of the three cables.
Straight-Through Cables
For this type of cable, the wiring of both ends is the same, in other words Pin 1 connector A goes to Pin 1 on connector B, Pin 2 to Pin 2 etc. Straight-through wired cables are most commonly used to connect a host to client. When we talk about cat 5e patch cables, the straight-through wired cat5e patch cable is used to connect computers, printers and other network client devices to the router switch or hub. Straight-through cable can be either terminated with T568A or T568B standard, just as you can see in the below image.
Crossover Cables
Crossover cables are very much like Straight-Through cables with the exception that TX and RX lines are crossed (they are at opposite positions on either end of the cable), that’s it, Pin 1 on connector A goes to Pin 3 on connector B. Pin 2 on connector A goes to Pin 6 on connector B, etc. Crossover cable are usually terminated with one end with T568A and the other end with T568B standard This means that two similar devices can communicate with each other, so this is how to connect two computers or two switches or hubs to each other. Crossover cables are most commonly used to connect two hosts directly. Examples would be connecting a computer directly to another computer, connecting a switch directly to another switch, or connecting a router to a router.
Rollover Cables
A rollover cable as the names implies, refers to the one where the pinouts are reversed. Pin 1 becomes pin 8 and pin 2 becomes pin 7. This type of cable is not used in computer networks, except in very special applications. Rollover cables, sometimes referred to as host cables are most commonly used to connect to a devices console port to make programming changes to the device. Unlike crossover and straight-wired cables, rollover cables are not intended to carry data but instead create an interface with the device.
Cabling Standards—T568A and T568B
Ethernet cables are twisted into 4 wires coded with different colors. The four colors used on Cat 5 and 6 cables are green, orange, blue and brown. One wire in each pair has a solid color and the other has a white stripe added. The telecommunication industry has two standards for cable RJ45 pinouts: T568A and T568B. These standards determine how each of the four pairs of colored wires is connected on the RJ45 connector.
When visually comparing the T568A and T568B wiring configurations side-by-side, you will see that that the pin positions for the green and orange pairs are swapped. On T586A cables, pin 1 is white-green and pin 2 green, whereas on T586B cables, pin 1 is white-orange and pin 2 orange. The difference continues in that pins 3 and 6 are used for the other color. With both standards, the blue pair is always on pins 4 and 5 and the brown pair on pins 7 and 8. T586B is the most common, although the government often uses T586A. The choice is irrelevant provided all components follow the same standard.
How to Configure Ethernet Cable for T568A or T568B
T568A and T568B standards were recognized by ANSI, TIA and EIA. The first is the T568A wiring standard and the second is T568B. Nowadays T568B has surpassed 568A and is seen as the default wiring scheme for twisted pair structured cabling. But this cannot be the unique standard to determine which one is suitable than the other. In fact, whether to choose one standard over the other really depends upon the configuration of the existing network you are working on or if you are building a network from the ground up. The benefit to using the more popular T568B wiring scheme is that it is backward compatible to USOC wiring schemes, but it also accommodates current and future demands on the network.
If you are working on an existing network, it is important to continue with the existing wiring scheme for straight through cables. If this is unknown, this can be determined by testing the cables for continuity. Mixing the two schemes will prevent data signals from transferring simply because the individual colored and striped wires will not be matching up when you connect the plugs and jacks. Or in some circumstance, it may be necessary to mix the two configurations when previously T568A-wired components will be connected to T568B components. In this case, you would want to create a crossover cable by terminating one end with a T568A terminated plug and the other with a T568B plug to prevent data loss.
Conclusion
The RJ45 pinout standards specify two wiring schemes on how to configure RJ45 Ethernet cable. While the T568A and T568B wiring standards are very similar, the T568B scheme is more commonly used for many data cable applications. Note that whether to use T568A or T568B really depends on the existing wiring, jacks or personal preference, and you should take consistency into account as well. FS.COM provides a full range of optical devices, including the Ethernet cables, fiber optic cables, optical transceivers, DAC/AOC and so on. Custom fiber patch cords are also offered. All of our products are well-tested before shipping, if you want to know more, please send your request to us.

How Should I Terminate My Fiber Optic Cable

In today’s day and age, we are more connected than ever. And we expect it.
At the work place we are attending virtual trainings on the latest technologies and we are connecting across the globe with our colleagues in real-time meetings – with just the click of a button.
When we leave work, we are going home using app-based scooters and bicycles that only needs the swipe of a cell phone. And if taking a highway home, you no longer search for change at a toll booth but instead you drive through a toll lane that scans and charges your account as you drive underneath it.
And it doesn’t stop at home. We are answering emails, while streaming Ultra HD video on our smart TV’s, all while having the latest super hero flick downloading on our tablet to watch on an upcoming business trip.
With the ever-increasing demand for the bandwidth needed to meet today’s expectations; how we design, install, and maintain our fiber optic networks must evolve with that same demand. In particular, the methods used to terminate, or connect, the ends of our fiber optic networks has evolved in the past 20 years quite drastically; starting with hand-polishing a ferrule with films and epoxies to achieve a finished termination. Hand epoxy polishing gave you a good, epoxy-cured connection but can be time consuming, and it took certain skill sets to achieve a good ferrule polish. Epoxy terminations lead to Mechanical Terminations which is the mechanical mating of fibers with the use of specific hand tools, v-groove alignment, and index matching gel to bridge the air gap between fibers. The benefits of using a factory-polished ferrule and the mechanical termination offered a time saving from traditional hand-polishing and allowed even some of the most novice of technicians the ability of putting a quality connector on in the field. As optical fusion splice machines and fusion splicing technology improved, technicians can now fusion splice a pigtail, a length of cable factory terminated on a single end, to a field cable that has been newly pulled or an old cable that needs to be repaired.
More importantly than any convenience of use though, is the performance of the termination. To enjoy some of the luxuries of connectivity mentioned before, we need a stronger optical signal to go farther than ever. Insertion Loss (IL) is a measurement of the optical power that is lost through a mated pair in decibels (dB). To compare the performance in IL of the three main termination methods, hand epoxy can typically range from .20dB – .75dB depending on installer. A typical mechanical style termination IL is 0.50dB, with loss accumulating from both the air gap of a mated pair, and the alignment of the fiber stub to your field fiber. Fusion splicing a pigtail or connector, is going to give your lowest loss of light through termination. Average fusion splice termination IL is .02dB – .05dB of loss through the splice, for a total of typical .20dB IL from your termination. By fusion splicing a connector in your network you are performing that much better in regards of your signal getting from source to receive.
Another important factor of your termination is how much light it reflects, you do not want your termination to be reflective. Reflectance is measured by how much light (dB) is returned back up the link, and the lower the number (farthest from 0) the better. The ferrule of your termination is the main factor in reflectance, and is categorized in 3 main stages: Physical Contact (PC), Ultra Physical Contact (UPC), and Angled Physical contact (APC). To throw a lot of numbers and letters around, PC polish typically has a reflectance of -30dB, UPC polish typical -40dB, and APC polish -65dB or better. Remember, the lower the number the least amount of reflection, so APC being -65dB is premium performance for optical termination because it returns the least amount of light per termination. Hand polishing connector does rely on skill, an experienced technician will be able to give you the best results but it still can be an imperfect science. Mechanical connectors allowed anybody to be able to put on a connector with the use of specific tools and simple termination procedures, but because of the reflectance of the matching gel, along with the mating of the ferrules, you will achieve around the -40dB referenced above. By being able to fusion splice a factory terminated pigtail to a field fiber, you achieve maximum performance of the ferrule polish due to the low reflectance fusion splice technology. A -65dB return loss on an APC termination is possible because a typical core alignment fusion splice is actually considered a non-reflective event. As we bring fiber closer and closer to the home, with lab environment transmission of 400gB of data over fiber, we can’t afford the return of light that our networks of days past allowed us.
With fusion splicing becoming the termination method of choice for performance, it’s now about installation and how we can make it easier. Pigtail splicing while practical, can be cumbersome with cable management and could require more rack space for that management. You prep your field fiber, you prep your pigtail, you splice them together and manage the slack, and you have a high performing termination.
The industry is now seeing Splice on Connectors as a popular choice of termination vs traditional pigtails because of the cost, space, and time savings they offer. Now you can use a factory terminated connector that can be spliced right at the end of your trunk cable, allowing a time savings in cable prep, a space saving without the excess length of traditional pigtails, and still giving your connection an Insertion Loss as low as .20dB, and a minimal return loss as low as -65dB. Splice on Connectors can arguably be your lowest cost, easiest to install, and best performing termination method.
In conclusion, I want to say that I am writing on my laptop while streaming a basketball game, my wife is streaming her reality TV while scrolling home improvement blogs on her phone, and our demand for bandwidth isn’t slowing down. As our use of technology evolves, so must our data networks. And in terms of how we terminate our fibers, the practice of using splice on connectors has us all trending in the right direction.