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Data Center 40G Migration with OM3 and OM4 Optical Connectivity

Why Migrate to 40G

With the quick development in data center, cabling infrastructures should provide manageability, flexibility and reliability. Deployment of optical connectivity solutions enables for an infrastructure meeting these requirements for current applications and data rates. Scalability is another key factor that needs to consider when choosing the type of optical connectivity. It refers to not only the physical expansion of the data center with respect to additional servers, switches or storage devices, but to the scalability of the infrastructure to support a migration path for increasing data rates. As technology evolves and standards are completed to define data rates such as 40G/100G, Fibre Channel (32G and beyond) and InfiniBand (40G and beyond), the cabling infrastructures installed today need to provide scalability to accommodate the need for more bandwidth in support of future applications. Moreover, current data rates cannot meet the needs of the future with the rising demand to support high-bandwidth applications. 40G technologies and standards, however, can support future networking requirements. Thus, a migration to 40G is required.

40 Gigabit Ethernet Standard

Ratified in June 2010, 802.3ba standard provides a guidance for 40G transmission with multimode and single-mode fibers. And this standard does not have guidance for Cat UTP/STP copper cable. OM3 and OM4 are the only multimode fibers included in the standard. Due to the 850nm VCSEL modulation limits, multimode fibers utilize parallel optics transmission instead of serial transmission. Single-mode fiber guidance utilizes duplex fiber WDM (wavelength-division multiplexing) serial transmission.

multimode fiber

Compared to single-mode fiber, multimode fiber offers a significant value proposition for short length interconnects in the data center. Unlike traditional serial transmission, parallel optics transmission utilizes an optic module interface where data is simultaneously transmitted and received over multimode fibers. The 40GBASE-SR4 supports 4 x 10G on four fibers per direction.

Cabling Performance Requirements for OM3/OM4

When evaluating the performance needed for the OM3 and OM4 cabling infrastructure, the following criteria should be considered. Each of the criteria would have an impact on the cabling infrastructure’s ability to meet the standard’s transmission distance of 100 meters over OM3 fiber and 150 meters over OM4 fiber.

Bandwidth is the primary criteria. OM3 and OM4 fibers are optimized for 850nm transmission and have a minimum 2000 MHz∙km and 4700 MHz∙km effective modal bandwidth (EMB). Fiber EMB measurement techniques are utilized today. The minimum EMBc (Effective Modal Bandwidth calculate) method combines the properties of both the source and fiber. With a connectivity solution using OM3 and OM4 fibers that have been measured using the minEMBc technique, the optical infrastructure deployed in the data center will meet the performance criteria set forth by IEEE for bandwidth.

Insertion loss is a critical performance parameter in current data center cabling deployments. Total connector loss within a system channel impacts the ability to operate over the maximum supportable distance for a given data rate. The supportable distance at data rate decreases with total connector loss increasing. The 40G standard specifies the OM3 fiber to a 100m distance with a maximum channel loss of 1.9 dB, which includes a 1.5 dB total connector loss budget. OM4 fiber is specified to a 150m distance with a maximum channel loss of 1.5 dB, which includes a 1.0 dB total connector loss budget. The maximum cable fiber attenuation is 3.5 dB/km at 850 nm. So the insertion loss specifications of connectivity components should be evaluated when designing data center cabling infrastructures. With low-loss connectivity components, maximum flexibility can be achieved with the ability to introduce multiple connector matings into the connectivity link.

Summary

Cabling deployed in the data center today must be selected to provide support of data rate applications of the future. To achieve this purpose, OM3 or OM4 is a must. They provide the highest performance for today’s needs. With 850nm EMB of 2000 MHz∙km and 4700 MHz∙km, the fibers provide the extended reach required for structured cabling installations in the data center. Except the performance requirements, the choice in physical connectivity is also important. Utilizing MTP-based connectivity in today’s installations provides ways to migrate to multifiber parallel optic interface when needed. Therefore, MTP-based connectivity using OM3 and OM4 fiber is the ideal solution in the data center. It can be installed for use in today’s applications, while providing an easy migration path to future higher speed technologies.

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How Much Do You Know Fiber Optic Testing?

For every fiber optic cable plant, you need to test for continuity and polarity, end-to-end insertion loss, etc. If there were a problem, it must be fixed to keep the fiber optic cable plant working properly and ensure the communications equipment operate well.

fiber-optic-testing

Testing Tools

Fiber optic cable testing needs special tools and instruments. And they must be appropriate for the components or cable plants being tested. The following five kinds of fiber testing tools are needed for the testing work.

OLTS—Optical loss test set (OLTS) with optical ratings matching the specifications of the installed system (fiber type and transmitter wavelength and type) and proper connector adapters. Power meter and source are also needed for testing transmitter and receiver power for the system testing.
Reference test cable—This cable should be with proper sized fiber and connectors and compatible mating adapters of known good quality. And the connector loss is less than 0.5 dB.
VFL—Visual fiber tracer or visual fault locator (VFL)
Microscope—Connector inspection microscope with magnification of 100-200X, video microscopes recommended.
Cleaning Materials—Cleaning materials intended specifically for the cleaning of fiber optic connectors, such as dry cleaning kits or lint free cleaning wipes and pure alcohol.

Notes Before Testing
Cleaning Issue

Before testing, it’s very important to keep connector clean so that there is no dirt present on the end face of the connector ferrule as the dirt will cause high loss and reflectance. For example, the dust caps which is used to keep connectors clean usually contain dust. So it may leave residue or cause harm to the connectors to use cleaning tools with dirt.

Eye Protection

Connector inspection microscopes focus all the light into the eye and can increase the danger. Some DWDM and CATV systems have very high power and they could be harmful. Though fiber optic testing sources are too low in power to cause eye damage, it’s still suggested to check connectors with a power meter before looking it. As most fiber optic sources are at infrared wavelengths that are invisible to the eye, making them more dangerous. So better protect your eyes from these potential harms.

Loss Budget

Before testing, you should clearly know the loss budget as reference loss values for the cable plant to be tested. Here are some guidelines:

    • For connectors, 0.3-0.5 dB loss; for adhesive/polish connectors, 0.75 dB loss; for prepolished/splice connectors (0.75 max from TIA-568)
    • For single-mode fiber, 0.5 dB/km for 1300 nm, 0.4 dB/km for 1550 nm. It means a loss of 0.1 dB per 600 feet for 1300 nm, 0.1 dB per 750 feet for 1550 nm.
    • For each splice, 0.2 dB
    • For multimode fiber, the loss is about 3 dB/km for 850 nm, 1 dB/km for 1300 nm. It means a loss of 0.1 dB per 100 feet for 850 nm, 0.1 dB per 300 feet for 1300 nm.

So for the loss of a cable plant will calculated as (0.5 dB X # connectors) + (0.2 dB x # splices) + fiber loss on the total length of cable.

Fiber Optic Loss Testing

Before installation, it’s necessary to inspect all cables as received on the reel for continuity using a visual tracer or fault locator. An OTDR is needed to test if cables are damaged during the shipment. Any cable showing damage should not be installed.

After installation, all cables should be tested for insertion loss using a meter of OLTS according to standards OFSTP-14 for multimode fiber and OFSTP-7 for single-mode fiber. Usually cables are tested individually (connector to connector for each terminated section of cable and then a complete concatenated cable plant is tested “end-to-end”, excluding the patch cords that will be used to connect the communications equipment which are tested separately. Insertion loss testing should be done at the wavelengths of 850/1300 nm with LEDs for multimode fiber, 1310/1550 nm with lasers for single-mode fiber, 1490 for FTTH. Keep the data on insertion loss for future comparisons if problems arise or restoration becomes necessary. Long cables with splices may be tested with an OTDR to confirm splice quality and detect any problems caused during installation, but insertion loss testing with an OLTS (light source and power meter) is still required to confirm end-to-end loss.

Testing Results and Methods

If the cable plant loss is tested within the loss budget, the communication link should work properly.

If the loss is higher than the loss budget, first you need to test in the opposite direction using the single-ended method. Since this method can only test the connector on one end, you can isolate a bad connector. If the tested losses are the same on both directions, you need to test each segment separately to isolate the bad segment or use an OTDR if it is long enough.

If there is no light through the cable and only darkness when tested with your visual tracer, there must be very high loss. Then you need to cut the connector on one end (maybe the wrong one) by your decision.

Originally published at http://www.articlesfactory.com/articles/communication/how-much-do-you-know-fiber-optic-testing.html

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Factors That Limit Optical Transmission Distance

Nowadays, fiber optic network is gaining its popularity because it has high speed, high density and high bandwidth, etc. Compared with traditional copper cable, the fiber optic cable could support much further distance although the exact distance is limited by many factors. For the super fast optical communication, transmission distance has already become the most vital issue. The optical signal may become weak over long distance. Thus, many components and methods have been adopted to break the limitations of the optical transmission distance. This article will emphasize the factors that limit optical transmission distance.

Optical Fiber Cable Type

Typically, the dispersion in the fiber optic cable could have a great impact on the transmission distance. There are two types of dispersion—chromatic dispersion and modal dispersion. Chromatic dispersion is the spreading of the signal over time resulting from the different speeds of light rays, while modal dispersion is the spreading of the signal over time resulting from the different propagation mode.

As it is known to all, optical fiber cable could be divided into single-mode fiber cable and multimode fiber cable. For the single-mode fibers, transmission distance is affected by chromatic dispersion, because the core of single-mode fibers is much smaller than that of multimode fibers. And this is the main reason why single-mode fiber can have longer transmission distance than multimode fiber. For the multimode fibers, transmission distance is largely affected by the modal dispersion. Due to the fiber imperfections, the optical signals of multimode fibers cannot arrive simultaneously and there is a delay between the fastest and the slowest modes, which causes the dispersion and limits the performance of multimode fibers (see the following picture).

modular dispersion

Light Source of Fiber Optic Transceiver

Fiber optic cable is the path sending the optical signals. However, most of the terminals are electronic based. The conversions between electrical signals and optical signals are necessary. Fiber optic transceivers are widely used in today’s optical network to achieve this purpose. The conversion of signals depends on a LED (light emitting diode) or a laser diode inside the transceiver, which is the light source of fiber optic transceiver. The light source can also affect the transmission distance of a fiber optic link.

LED diode based transceivers can only support short distances and low data rate transmission. Thus, they cannot satisfy the increasing demand for higher data rate and longer transmission distance. For longer and higher transmission data rate, laser diode is used in most of the modern transceivers. The most commonly used laser sources in transceivers are Fabry Perot (FP) laser, Distributed Feedback (DFB) laser and Vertical-Cavity Surface-Emitting (VCSEL) laser. The following chart shows the main characteristics of these light sources.

light source of fiber optic transceiver

Frequency of Transmission

As is shown in the above chart, different laser sources support different frequencies. The maximum distance of fiber optic transmission system can support is affected by the frequency at which the fiber optic signal will be transmitted. Generally the higher the frequency, the longer distance the optical system can support. So it is essential to select the right frequency to transmit optical signals. Typically single-mode fibers use frequencies of 1300 nm and 1550 nm, while multimode fibers use frequencies of 850 nm and 1300 nm.

Bandwidth

Another factor influencing the transmission distance is the bandwidth of fiber optic cables. Generally, the transmission distance decreases proportionally, as the bandwidth increases. For example, a fiber that can support 500 MHz bandwidth at a distance of one kilometer will only be able to support 250 MHz at 2 kilometers and 100 MHz at 5 kilometers. Single-mode fibers have an inherently higher bandwidth than multimode fibers due to the way in which light passes through them.

Splices and Connectors

Splices and connectors in most fiber optic system are inevitable. Signal loss can be caused when the optical signal passes through each splice and connector. The total amount of the loss depends on the types, quality and number of connectors and splices.

Conclusion

According to the above statement, the optical transmission distance is affected by various factors including the fiber type, light source of transceiver, frequency of transmission, bandwidth as well as splices and connectors. So it is necessary to consider these factors to minimum the limitations on transmission distance when deploying the fiber optic network.

Originally published at http://www.fiberopticshare.com/factors-that-limit-optical-transmission-distance.html

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How to Make, Lay and Repair Submarine Cables?

Ninety-nine percent of international data is transmitted by submarine communication cables laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean. These undersea cables are hundreds of thousands of miles long and can be as deep as Everest Is tall, as well as enable our globalized society by facilitating the transfer of digital information. This article will tell how to make, lay and repair submarine cables.

How to Make Submarine Cables?

The core of undersea cables is covered with brass tape which is impervious to the assault of the aqueous worm called teredo which is the greatest enemies of submarine cables. The completed core with the brass taping is fully wrapped by jute yarn, a coarse hemp, steeped in a tarry preservative. Wound around the core, this jute yarn serves as a bedding for the outer protecting wires. After several servings of the jute yarn have been applied to the core, the whole is then covered with galvanized iron wires which vary in number and thickness according to the depth of water the cables is to lay in.

Cables laid in deep water are lighter than those laid in shoaler water. Why? Because if the cables are too heavy in deep water, the strain of raising cables would be so great that it may be impossible to recover the cables for repair purposes. Moreover, there is very little to injure submarine cables in the deep water.

How to Lay Submarine Cables?

The laying of long submarine cables is not easy. The telecom engineers toil long and tedious hours to make this possible. Submarine cables are laid down by using specially modified ships. On reaching the place selected for the landing of the cable, the ship approaches as close to the shore as possible and, letting go anchor, prepares to land the shore end. Some companies use rafts to achieve this, while others use a couple of spider-sheaves, or large VV-shaped wheels in light iron frames are sent ashore and fixed by sand anchors some 60 yards apart. Hauling lines are paid out from the ship, reeved through the sheaves and brought back on board again. One end of this continuous lines is attached to the picking-up gear and the other to the cable. The engines are then set in motion, and the cable is dragged slowly out of the ship towards the shore. As it goes, large wooden casks or inflated India rubber buoys are lashed to it every 50 or 60 feet, to keep it afloat and prevent the damage which would result from it being dragged along the bottom.

submarine cable

When sufficient cable has been landed, the length on shore is laid in a trench which runs from low water mark to the cable landing station (CLS), and the end is inserted through a hole in the floor. Then there will be testing and speaking instruments set up in the CLS. For day and night, the testing goes on. The ship gets slowly under way when a satisfactory test has been taken.

How to Repair Submarine Cables?

The first indication that a cable is broken or faulty is the failure of the receiving apparatus to properly record incoming signals. When a break or a fault in the line is indicated by the receiving instruments, a test is immediately made from each end of the line. These tests are taken with very sensitive apparatus. Several methods of testing are employed in the localization of complete or partial interruptions of cables, with the most general being the Wheatstone Bridge balance.

The operation of repairing submarine cables is no child’s play. It is a kind of work which requires sturdy and fearless manhood as well as skillful seamanship. Most of the breaks happen during seasons of the year when the weather conditions at sea are most severe. It is common for a cable ship to spend months at sea waiting for suitable weather conditions to carry on operations.

Conclusion

By reading the above statements, have you got more knowledge about the submarine cables’ making, laying and repairing? It may not be rich in content, but submarine cables are indeed important members of fiber cables and do play an important role in international data transmission.

Originally published: www.roarsummit.com/how-to-make-lay-and-repair-submarine-cables-1551133696.html

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How to Choose a Right OTDR?

An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to measure fiber loss, the loss and reflectance of fiber splices, and to locate loss irregularities within the fiber. Now there are many types of OTDRs providing different test and measurement needs including very simple fault finders and advanced OTDRs for link certification. Then, how to choose the right one?

aq1200-mft-otdr

First, you should evaluate your needs. Installing or maintaining fiber? For simple maintenance, a simple or low cost OTDR is good. It’s easy to use, requires the lowest possible investment and some even provides total link loss and optical return loss values. For not very complex installation, you should choose a mini OTDR based on the following key parameters for your specific environment.

Dynamic Range

This specification determines the total optical loss that the OTDR can analyze; i.e., the overall length of a fiber link that can be measured by the unit. The higher the dynamic range, the longer the distance the OTDR can analyze. Insufficient dynamic range will influence the ability to measure the complete link length and affect the accuracy of the link loss, attenuation and far-end connector losses. It’s good to choose an OTDR whose dynamic range is 5 to 8 dB higher than the maximum loss you will encounter.

Dead Zones

Dead zones originate from reflective events (connectors, mechanical splices, etc.) along the link, and they affect the OTDR’s ability to accurately measure attenuation on shorter links and differentiate closely spaced events, such as connectors in patch panels, etc. There are two types of dead zones to specify OTDR performance:

Attenuation dead zone refers to the minimum distance required, after a reflective event, for the OTDR to measure a reflective or non-reflective event loss. Try to choose OTDR with the shortest possible attenuation dead zone to measure short links and to characterize or find faults in patchcords and leads. Industry standard values range from 3 m to 10 m for this specification.

Event dead zone is the distance after a reflective event starts until another reflection can be detected. If a reflective event is within the event dead zone of the preceding event. Industry standard values range from 1 m to 5 m for this specification. The event dead zone specification is always smaller than the attenuation dead zone specification.

Sampling Resolution

Sampling resolution refers to the minimum distance between two consecutive sampling points acquired by the instrument. This is a quite important parameter as it defines the ultimate distance accuracy and fault-finding capability of the OTDR.

Pass/Fail Thresholds

This parameter is also important because lots of time can be saved in the analysis of OTDR traces if you set Pass/Fail thresholds for parameters of interest (e.g., such as splice loss or connector reflection). These thresholds highlight parameters that have exceeded a Warning or Fail limit set and, when used in conjunction with reporting software, it can rapidly provide re-work sheets for installation/commissioning engineers.

Report Generation

If an OTDR has specialized post-processing software allowing fast and easy generation of OTDR reports, it can save up to 90% post-processing time. These can also include bidirectional analyses of OTDR traces and summary reports for high-fiber-count cables.

To choose a right OTDR for your test application, you should better consider the above factors. Fiberstore offers YOKOGAWA AQ1200A, EXFO AXS-110-23B-04B OTDR, etc,. with great accuracy, measurement range and instrument resolution. There must be one suitable for you and helpful to maximize your return on investment.

Originally published at http://www.articlesfactory.com/articles/communication/how-to-choose-a-right-otdr.html

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Splice or Connector: Which to Choose for FTTH Drop Cable Installation?

When deploying a FTTH network, subscribers must choose the right drop cable interconnect solution. So they need to decide whether to use splices (permanent joint) or connectors (easily mated and unmated by hand) for the best solution. This is for both ends of the drop cable—the distribution point and at the home’s optical network terminal (ONT) or network interface device (NID). Splices and connectors are widely used at the distribution point, while at the ONT/NID, a field-terminated connector or a spliced-on factory-terminated connector is used. This paper discusses the available interconnect solutions (splices and connectors) for FTTH drop cables and their own pros and cons.

Splices: Pros and Cons

Excellent optical performance is the most significant advantage of splices. And splicing can also eliminate the possibility of the interconnection point becoming dirty or damaged, potentially compromising signal integrity, as may happen to a connector end face when it is being handled while unmated. Contaminants will cause high optical loss or even permanently damage the connector end face. Splice enables a transition from 250µm drop cable to jacketed cable.

The major drawback of splice is its lack of operational flexibility. To reconfigure a drop at the distribution point (in the case of one subscriber dropping FTTH service and another one adding it) one splice must be removed, fibers rearranged, and two new fibers spliced. Then it requires the technician to carry special splicing tools for simple subscriber changes. Moreover, other customers’ service may be disrupted by the fiber-handling process. 250µm fiber cable is usually used at the distribution point, which is easily bent and then cause high optical loss or even break the fiber. If a splice is used at the ONT, a tray is needed to hold and protect the splice, which increase the ONT size and potentially the cost.

According to above description, splice is appropriate for drops where there is no need for future fiber rearrangement, typically in a greenfield or new construction application where all of the drop cables could be easily installed during the living unit construction.

Connectors: Pros and Cons

Due to the characteristic of being mated and unmated repeatedly, connectors can provide greater network flexibility. Without any tools, a technician can easily connect or disconnect subscribers. Connector could also provide an access point for networking testing.

Material cost is the connector’s most obvious downside. They cost more than splices, although network rearrangement is much cheaper. So providers need weight the connector’s material cost and its potential for contamination and damage against the greater flexibility and lower network management expense.

Connectors could be used to connect different subscribers as needed for distribution points. It must be installed at the ONT and then offers flexibility both at the curb and at the home.

Choose the Right Splice

Once the decision goes to splices, the type of splicing (fusion and mechanical) must be determined.

Fusion splicing has been the de facto standard for fiber feeder and distribution construction networks. Fusion splicer is used for FTTH drop splicing as it provides a high quality splice with low insertion loss and reflection (see the picture below). However, the initial capital expenditures, maintenance costs and slow installation speed of fusion splicing hinder its status as the preferred solution. Fusion splicing is best suited for companies which have invested in fusion splicing equipment and have no need to purchase additional splicing machines.

FS2808 Digital Fiber Fusion Splicer

Mechanical splices are successfully deployed around the world in FTTH installation, but not popular in United States because the index matching gel inside the splices can yellow or dry out, resulting in service failures. Great strides have been made in improving gel performance and longevity over the last 20 years.

Choose the Right Connector

Once choosing to use a connector, a factory-terminated or field-terminated connector must be decided.

Factory-terminated drop cables provides high-performing and reliable connections with low optical loss. By reducing installation time, factory termination keeps labor costs low. However, factory-terminated cables are expensive compared to field-terminated alternatives. And they require a cable management system to store slack cable at the curb or in home.

The installation of field-terminated connectors can be customized by using a reel of cable and connectors. Fuse-on connectors use the same technology as fusion splicing to provide the highest level of optical performance in a field-terminated connector. Mechanical connectors provide alternatives to fuse-on connectors for field installation of drop cables.

Depending upon service provider requirements and living unit configurations, a hybrid solution of a field-terminated connector on one end of the drop cable and a factory-terminated connector on the other may be the optimal solution.

Summary

The drop cable interconnect solution is a key component of a FTTH network. Selecting the right connectivity product not only offers cost savings and efficient deployment but also provides reliable service to customers. Most FTTH drop cable installations have been field terminated on both ends of the cable with mechanical connectivity solutions.

Article source: article-realm.com/public/article/index/id/313702/artilce

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Which One Will You Choose? Cat 5e, Cat 6 or Cat 6a?

Copper is the oldest installed cable and it’s still widely used for connecting devices. Till now, copper cable has gone through several generations to meet people’s increasing needs of different sides. There are many types of copper cables offering different performance such as Cat 5e, Cat 6 or Cat 6a. What kind of copper cabling should you choose? This is a really confusing question people usually meet today. This article will introduce some details about these three kinds of copper cables and help you make your decision.

cat5e-cat6-cat6a

Cat 5e

Cat 5e, also known as Enhanced Category 5, is designed to support full-duplex Fast Ethernet operation and Gigabit Ethernet. In 1998, Gigabit Ethernet was introduced. Then, the original Cat 5 was found not good enough to guarantee error-free performance. So extra requirements were added to Cat 5, such as Return Loss, Delay, Delay Skew and Power Sum Crosstalk measurements. With these improved parameters, Cat 5e came into being to ensure reliable operation of Gigabit Ethernet. The electrical performance for Cat 5e requirements is up to 100MHz.

Cat 6

Cat 6 was designed as the next generation to Cat 5e. It has higher standards construction than Cat 5e with a bandwidth of up to 250 MHz rather than 100 MHz. It can support the faster protocols and is therefore considered more reliable than Cat 5e. It is ideal for 10 Gigabit Ethernet transmissions.

Cat 6a

Cat 6a has a bandwidth of up to 500 MHz and is designed to support 10 Gigabit Ethernet transmissions over 100 meter channel. It’s also compatible with Cat 5e and Cat 6. A new electrical parameter measure of “alien crosstalk”, which is a measurement of the noise crosstalk generated from neighboring cables, was introduced to ensure that Cat 6a cabling system can run 10 Gigabit Ethernet transmissions well.

Common Features of Three Types

The three kinds of cables are unshielded twisted pair (UTP) or shielded twisted cables. They use 4 twisted pairs in a common jacket and the same RJ-45 jacks and plugs. And they are limited to a cable length of 100 meters including the length of the patch cables on either end of the link. The parts are interchangeable. That means you can use a Cat 5e patch cable with Cat 6 house cabling. But your system will perform at the lowest link level.

Differences of Three Types

The most noticeable difference of these cables is the price. According to statistics, plan on Cat 6 will cost roughly 30% more than Cat 5e and Cat 6a 30% more than Cat6. But the price is not the only factors to decide which kind of cable should be used.

  • Transmission Performance: Cat 5e has a bandwidth of up to 100 MHz. It has a reduced maximum length of 45 meters when used for 10 Gigabit Ethernet applications. Cat 6 cable is rated for 250 MHz. It can support 10 Gigabit Ethernet up to 55 meters. While Cat 6a performs at up to 500 MHz, so it allows 10 Gigabit Ethernet to be run over distances of up to 100 meters. Cat 6a has a better transmission performance than Cat 6 and Cat 5e. But this doesn’t mean the network ‘speed’ of Cat 6a is faster. These are electrical performance differences.
  • Crosstalk: Crosstalk is a complicated subject to grasp and has been talked before. It is the phenomenon in which a signal from one channel or circuit interferes with another channel or circuit’s signal. Cat 6 cable has lower signal degradation from near-end crosstalk (NEXT), power sum NEXT (PS-NEXT) and attenuation than Cat 5e. Cat 6a reduces this to an even lower level.
  • Physical Properties: Cat 6a has bigger size and more weights than Cat 5e and Cat 6. It will take up more space for installation. And because of the larger cable diameter, Cat 6a needs a bigger bend radius. So it’s important to allow extra space anywhere for Cat 6a cables. Since it’s capable of speeds up to 500 MHz and Alien Crosstalk begins at only 350 MHz, Cat 6a needs more testing.
Which One Should You Choose?

For most of copper network applications, Cat 5e is good enough to give all the performance we are likely to need today. But if you are looking for a cable for your future needs, then Cat 6a will give you the best performance at full distances. So it depends on what you will do with the cable. You should also consider the price and space.

Originally published at http://www.fiber-optic-equipment.com/which-one-will-you-choose-cat-5e-cat-6-or-cat-6a.html