Straight-Through vs. Crossover Ethernet Cables

Ethernet cables or networks cables are used for data transmission between devices on a network. They consist of a copper cable with 4 pairs of wires and connected by RJ45 connectors on each end of the cable. Most Ethernet cables in use today are either Cat5e and Cat6 which offer higher data transfer rates than the older types such as Cat5 and Cat4. Although various types of Ethernet cables look the same, the internal wiring distinguishes. Ethernet cables can come in two different wiring applications: straight-through and crossover, each of them with different wire arrangement in the cable for serving different purposes.

Straight-Through Ethernet Cables

Straight-through cable is the most common type and is used to connect different type of devices. This type of cable is easy to find in stores and can be used to:
1)Connect a computer to a switch/hub’s normal port.
2)Connect a computer to a cable/DSL modem’s LAN port.
3) Connect a router’s WAN port to a cable/DSL modem’s LAN port.
4) Connect a router’s LAN port to a switch/hub’s uplink port. (normally used for expanding network)
5) Connect 2 switches/hubs with one of the switch/hub using an uplink port and the other one using normal port.

If you need to check how straight-through cable looks like, it’s easy. Both side (side A and side B) of cable have wire arrangement with same color. For example, Cat5e UTP cable usually uses only four wires when sending and receiving information on the network. The four wires, which are used, are wires 1, 2, 3, and 6. When you configure the wire for the same pin at either end of the cable, this is known as a straight-through cable.

Straight-Through Ethernet Cables

Crossover Ethernet Cables

Crossover cables are usually used to connect the same type of devices and may be a little harder to find since they aren’t used nearly as much as straight-through cables. A crossover cable can be used to:
1) Connect 2 computers directly.
2) Connect a router’s LAN port to a switch/hub’s normal port. (normally used for expanding network).
3) Connect 2 switches/hubs by using normal port in both switches/hubs.

Compared with straight-through Ethernet cables, the internal wiring of crossover cables reverses the transmit and receive signals. That is to say, the two end of the crossover Ethernet cable are wired differently. And the reversed color-coded wires can be seen through the RJ-45 connectors at each end of the cable.

Crossover Ethernet Cables

Identifying Straight-Through and Crossover Cables

Whether they are straight-through or crossover cables, all Ethernet cables essentially look the same. When dealing with the inevitable pile of unlabeled cables that forms in every home, this can make dealing with them tricky. Fortunately, you can quickly identify crossover and straight cables if you know what to look for.

When determining if an Ethernet cable is a straight or crossover cable, examine the connectors. Observe the pin configuration carefully. The pins are color coded, so you should have no trouble doing this. If the pins are configured in the same way, you are looking at a straight cable. If not, it is a crossover cable.

Conclusion

Nowadays, the need for crossover cables has been eliminated with more modern equipment. Gigabit Ethernet was created with a widely used option called Auto-MDIX (automatic medium-dependent interface crossover). This technology detects whether you need a crossover cable or a straight-through cable, and it automatically configures the network interface card accordingly, which means that crossover function would be enabled automatically when it’s needed.

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Demystifying Ethernet Category Types

Ethernet represents the plumbing pipes of the Internet. Many network installers are familiar with Cat5e and Cat6 cables with RJ45 connectors. But the term “Ethernet”, co-invented by Robert Metcalfe, encompasses an entire range of twisted pair and fiber cables that are constantly being upgraded and standardized by the Institute of Electrical and Electronics Engineers known as IEEE. Each new iteration of Ethernet, or category, supports increasingly faster bandwidth speeds.

ethernet patch cable

Category 3

Cat3 cable is an earlier generation of Ethernet but can still be seen in older deployments. With the ability to support a maximum frequency of 16 MHz, this type of Ethernet can still be used for two-line telephone systems and 10BASE-T networks. CAT3 cable can also be used for alarm system installation or similar applications. CAT3 cable can have 2, 3, or 4 copper pairs (though uncommon). Category 5e cable however, has become the default Ethernet category of choice with the ability to support faster speeds and frequencies.

Category 5

Cat5 Ethernet, introduced 10/100 Mbps Ethernet, also known as Fast Ethernet. Even though some older deployments still use CAT5 cable, it is now considered obsolete and has since been replaced by Cat5e.

Category 5e

Although Cat5 and Cat5e cables are physically similar, Category 5e Ethernet adheres to more stringent IEEE standards. Cat5e is the most common type of cabling used for deployments due to its ability to support Gigabit speeds at a cost-effective price. Even though both Cat5 and Cat5e support a maximum frequency of up to 100MHz, Cat5e has completely replaced its predecessor. Gigabit Ethernet utilizes 4 data pairs in comparison to Fast Ethernet which utilizes 2 data pairs.

Cat 5e is perfectly fine. Many companies are placing more and more servers on the cloud. This means that if everything you do is on the cloud, and you require very little internal networking, your limiting factor will not be the type of cable, but the speed of your Internet. Quite likely, Cat 5e will achieve faster connections than your Internet speed, making Cat 5e the choice of most users.

Category 6

Cat6 network cables have been around for only a few years less than Cat5E cables. However, they have primarily been used as the backbone to networks, instead of being run to workstations themselves. The reason for this (beyond cost) is the fact that, while Cat6 cables can handle up to 10 Gigabits of data, that bandwidth is limited to 164 feet — anything beyond that will rapidly decay to only 1 Gigabit (the same as Cat5E).

Cat6 wiring can support up to 10 Gbps and frequencies of up to 250 MHz. While Cat5e cable features 1.5-2 twists per cm, Cat6 cables are more tightly wound and feature 2 or more twists per cm. Cat6 cables also sport thicker sheaths compared to Cat5e. Though standard Ethernet supports distances of up to 100 meters, CAT6 cable only supports 55 meters when transmitting 10Gbps speeds. Even though Cat6 and Cat6a cabling offers higher performance rates, many LANs still opt for CAT5e due to its cost-effectiveness and ability to support Gigabit speeds. When transmitting at 10Gbps speeds, Cat6 cables only support a maximum distance of 37 meters.

Category 6a

Cat6a can support bandwidth frequencies of up to 500 MHz, twice the amount of Cat6 cable, and can also support 10Gbps like its predecessor. However, unlike Cat6 cabling, Cat6a can support 10 Gigabit Ethernet at 100 meters. Cat6a cabling on the other hand, can transmit the same speeds at up to 37 meters. Cat6a also features more robust sheathing which eliminates alien crosstalk (AXT) and improves upon the signal-to-noise ratio (SNR). The stronger sheathing makes Cat6a cabling considerable thicker than Cat6.

Category 7

Cat7 can also support 10 Gbps, but laboratory testing has successfully shown its ability to transmit up to 40 Gb at 50 meters and even 100 Gb at 15 meters. The cabling can support frequencies of up to 600 Mhz. Cat7 offers extensive shielding to reduce signal attenuation and is relatively stiff in comparison to previous generations of cabling. The shielding needs to be grounded and Cat7 also requires special GigaGate45 (CG45) connectors.

Which type of Ethernet cable you should choose depends on your specific applications and requirements. When you plan to purchase Ethernet cables, you need to consider their differences like transmission distance, cost, durability, etc. Hope this post would help you choose the suitable cable and build a high-performing and future-proofing network.

Introduction to Cat6 Ethernet Cables

The Emergence of Cat6 Cable

Category 6 (CAT6) is an Ethernet cable standard defined by the Electronic Industries Association and Telecommunications Industry Association (commonly known as EIA/TIA). CAT6 is the sixth generation of twisted pair Ethernet cabling. Cat6 increases the bandwidth of the Cat5/5e from 100MHz to 250 MHz and allows for better signal to noise ratio with minimal loss which ensures faster and reliable networks. Cat6 also has many benefits compared to the Cat5/5e such as backwards compatibility, ease of installation, high performance, faster speeds, and higher capacity.

How CAT6 Cable Works

Category 6 was designed to support Gigabit Ethernet data rates (1 gigabit per second – Gbps). It additionally can support 10 Gigabit Ethernet connections over a limited distance (technically, 50 meters or 164 feet for a single cable).

CAT6 cable contains four pairs of copper wire and utilizes all of these pairs for signaling in order to obtain the higher level of performance.

Other basic facts about CAT6 cables
  • Ends of a CAT6 cable use the same RJ-45 standard connector as previous generations of Ethernet cables.
  • Printing along the length of the cable sheath identifies it as “CAT6”.
  • An enhanced version of CAT6 called CAT6a supports up to 10 Gbps speeds.
CAT6 vs. CAT6A

The Category 6 Augmented (CAT6A) cable standard was created to further improve on the performance of CAT6 for Ethernet cables. Using CAT6A enables 10 Gigabit Ethernet data rates over a single cable run up to 100 meters (328 feet). twice as far as CAT6, which supports 10 Gigabit Ethernet also, but only over distances up to 50 meters (164 feet). In return for the higher performance, CAT6A cables tend to cost noticeably more than their CAT6 counterparts, and they are slightly thicker (but still use standard RJ-45 connectors).

CAT6 vs. CAT5e

The history of cable design for Ethernet networks resulted in two separate efforts to improve on the previous generation Category 5 (CAT5) cable standard. One eventually became CAT6. The other, called Category 5 enhanced (CAT5e), was standardized earlier. CAT5e lacks some of the technical improvements that went into CAT6 but also supports Gigabit Ethernet installations, and at a lower cost.

Like CAT6, CAT5e utilizes a four wire pair signaling scheme to achieve the necessary data rates. (In contrast, CAT5 cables contain four wire pairs but keep two of the pairs dormant.)

Because it became available in the market sooner and offered “good enough” performance for Gigabit Ethernet at a more affordable price point, CAT5e became a very popular choice for wired Ethernet installations. This plus the relatively slow transition of the industry to 10 Gigabit Ethernet has significantly slowed the adoption of CAT6.

Limitations of CAT6

As with all other types of twisted pair EIA/TIA cabling, individual CAT6 cable runs are limited to a maximum recommended length of 100 meters (328 feet) for their nominal connection speeds (Gigabit Ethernet). As mentioned above, CAT6 supports 10 Gigabit Ethernet connections also but not at this full distance. Besides, CAT6 cable price is a little higher than that of CAT5e cable. So before choosing it, you’d better measure whether it is worth the extra cost.

Cat7 Ethernet Cable: Is It Worth The Extra Cost?

Nowadays, homes and businesses are operating on either a wired network connection or a wireless connection. Wired connections are usually faster than wireless connections and have lower latency. Both types of network hardware continue to advance, allowing users to benefit from faster speeds.

This might not be a big deal for the home network where the internet connection speed is usually the bottleneck. But businesses need to consider what kind of cables they are using. When using different types of Ethernet cables, the network speeds differ.

Comparing Other Cables To The Cat7 Ethernet Cable

Let’s start with the most standard types of Ethernet cables. Most of the new ones that are purchased in stores or bundled with equipment are probably recent enough that you do not need to worry. Companies that are still using older Ethernet cables they’ve had for a long time more than likely need to upgrade to a newer version.

Cat7 Ethernet Cable

Cables are not a brand name or generic; they are separated into different standard categories. The most common include Category 5, Category 5e, Category 6 and Category 6a. The newest cable category is 7. Each cable is backward compatible – meaning, you can plug a newer cable into a device created for a slower cable, and you will not have any compatibility problems.

Category Cable Progression

Each newer cable standard allows the user to get higher possible speeds with lower crosstalk. This enables the user to get those fast speeds, even with longer cables. When compared at lengths of 100 meters of cable, the following numbers show the difference in Ethernet cable categories:

  • Cat5 ethernet cable is typically too slow for business networks, allowing the user to get up to 100 Mb/second speed at 100 Mhz
  • Cat5e network cable allows up to 1 Gb/s internet speed with 100 Mhz
  • Cat6 ethernet cable allows up to 1 Gb/s, but cable lengths up to 55 meters can get internet speeds of 10 Gb/s at 250 Mhz
  • Cat6a ethernet cable can get speeds up to 10 Gb/s, even at 100 meters of cable length, operating at 500 Mhz
  • Cat7 ethernet cable is the newest cable category, operating at speeds of 10 Gb/s at 100 meters of cable and transmitting frequencies up to 600 Mhz.
A Little History

The Cat5 cable was the standard in 1995, Cat5e was standard in 2001 and Cat6 came out in 2002. The Cat6a has been around since 2008. Most businesses still have no need for updating their hardware to Cat7 Ethernet cable, much less the Cat7a or Cat8 cables that were first released in 2010 and 2013.

Cable can only allow the power and speeds of whatever equipment and internet type it is working with. Getting a faster cable will not change the internet speed if the equipment is set for a slower speed or the internet speed package is slower.

Most Cat5 and Cat5e cable should be changed out for a business set up. We believe that upgrading as high as Cat6a ethernet cable will be necessary for quite some time. Until companies need the speed, have the equipment to handle the speed and get an internet package that requires faster channels, the Cat7 ethernet cable’s full potential will simply not be used. This makes it an expensive, unnecessary upgrade. Purchasing and running cable is not a small expense, so companies should try to pick their cable in line with what they need currently and will need in the near future.

Solid or Stranded Ethernet Cables

Another difference in the cables will be the way the wires are used within the cable. The solid cable uses one single piece of copper for an electrical conductor. The stranded cable uses multiple (and thinner) copper cables twisted together for the electrical conductor. This makes the stranded cable more flexible, perfect for navigating a complex space. The solid cable is far less flexible making it ideal for permanent installation in the walls or outdoor.

Be sure to make clear of the features and difference between each type of Ethernet cables before finally selecting the one for your home or business project. Hope the information in this article could be helpful or a guide for you when you are confused about which Ethernet cable to choose.

The Evolution of Ethernet Nomenclature

To address new reaches, new media, and new speeds on links, Ethernet is continuously expanding into new applications and has become the dominant data communication channel in the world. From the basic twisted pair technology of BASE-T, Ethernet nomenclature has mirrored the evolution of the copper physical layer to include other copper cabling and backplane connections. This article will introduce the industry nomenclature of the most common types of Ethernet ports.

Ethernet (10 Mbps)

The first standard version of Ethernet used coaxial cable and operated at 10 Mbps. The main type of 10 Mbps Ethernet deployed today is 10BASE-T. 10BASE-T operates over two Twisted-pairs of telephone wire (26 to 22 AWG), or better, terminated with RJ-45 connectors. The two twisted-pairs are used as two simplex links: one twisted-pair to transmit in one direction and one twisted-pair to transmit in the other direction. While many switches support 10BASE-T for backward compatibility, most ports auto-negotiate to the higher speeds of either 100BASE-T or 1000BASE-T.

Since the majority of Ethernet ports sold have an RJ-45 connector and support 10BASE-T, 100BASE-T and 1000BASE-T, these ports are often referred to as 10/100/1000 or 10/100/1000BASE-T ports. The RJ-45 is found on almost every personal computer and Ethernet switch.

Fast Ethernet (100 Mbps)

Fast Ethernet operates at 100 Mbps and has the largest installed base of links. The main types of Fast Ethernet links are 100BASE-TX, 100BASE-FX and 100BASE-LX. 100BASE-X links use 4B/5B coding to encode and decode the data and is specified eXternal to the IEEE 802.3 standard by referencing to the FDDI standard. 100BASE-TX, which is almost universally known by the vernacular of 100BASE-T, operates over two Twisted-pairs of Cat5 cable or Cat6 cable terminated with RJ-45 connectors. 100BASE-T increases the speed of 10BASE-T by an order of magnitude and uses the same two twisted-pairs of wires as 10BASE-T.

Cat6 cable

100BASE-FX was the first 100Mbps Fiber link to be defined and used “F” as the “additional distinction” field of the port name. 100BASE-FX links use two 62.5μm “FDDI grade” multimode fibers to support up to at least 2 kilometers. Since 100BASE-LX10 uses Long wavelength lasers at 1310 nm, eXternal coding and supports at least 10kilometers over single-mode fibers, “LX10” was used as the “additional distinction” field of the port name. In both cases the fibers use two simplex links. Over 90% of Fast Ethernet links are 100BASE-T links.

Gigabit Ethernet (GbE)

Gigabit Ethernet (GbE) ports have been the workhorse of the data center for several years now and began shipping more ports than Fast Ethernet for the first time in 2010. Over 90% of GbE links are 1000BASE-T links that operate over four Twisted-pairs of Category 5 cabling, or better, terminated with RJ-45 connectors. The four twisted-pairs are used as four duplex links where all four twisted-pairs are used to transmit in both directions at the same time while 10 and 100 Mbps Ethernet use only two simplex pairs.

All other GbE links are in the 1000BASE-X family and use eXternal 8B/10B coding to encode and decode the data. The eXternal source for the coding in the IEEE 802.3 standard is the Fiber Channel standard. For shorter distances up to 25 meters where structured cabling is not required, 1000BASE-CX uses copper cables and eXternal source coding. 1000BASE-CX uses a jumper cable assembly that contains two pairs of twin axial cable terminated with D-sub connectors.

Conclusion

Ethernet has grown and evolved over the years. Apart from the three original types of Ethernet ports mentioned above, 10 Gigabit Ethernet, 40 Gigabit Ethernet, 100 Gigabit Ethernet and even above have already been put into wide use. Nowadays, Ethernet is the most ubiquitous networking technology. It has grown from its roots in enterprise networks, and now addresses other markets such as data centers, storage, metro, wide area, and carrier networks.

Modular Patch Panel Solution for Network Upgrade

The increasing demand for faster access to larger volumes of data, emerging high-speed network standards and rapidly advancing technology make it essential to integrate equipment with different network speeds into your network infrastructure. Modular patch panel solutions allow you to seamlessly and conveniently integrate equipment with 10G, 40G and 100/120G speeds to meet your connectivity needs future-proof your networks.

Tendency in Data Centers

When you plan to integrate 10G and 40G equipment in your data center, you’re supposed to make sure that the existing network of 10G servers and other devices can be connected to your higher-speed switches like 40G switches. And connectivity with future network standards should be taken into consideration as well. Although multiple-speed applications coexist in the same data center is not a fresh topic, the parallel optics cabling used for data transmission speeds of 40G and beyond does present a series of connectivity challenges.

What Is Modular Patch Panel Solution

Modular patch panels are comprised of rack-mountable enclosures to house a range of modular and removable fiber cassettes. By supporting various fiber network cabling standards, the cassettes are easy to mix, add and change according to your changeable connectivity needs. Modular patch panels is an ideal way to create a standard-based, flexible, and reliable network platform in data centers.

The key to modular patch panels solution is modular fiber cassettes, which are available in multiple variations. The cassettes allow you to interconnect different fiber speeds simply by plugging standard duplex LC cables into one side of the cassette and one or more standard MPO/MTP cables into the other side.

modular patch panel solution

Benefits of Modular Patch Panel Solution
  • Integrating various cabling standards—modular patch panel solutions allow you to connect diverse network cabling standards seamlessly, including 10/10G, 10/40G, 40/40G, 10/100/120G and 40/100/120G, as well as future standards.
  • Utilizing standard patch cords—Since connections use standard patch cords that are readily available, you can make changes and repairs without the delays and added expense associated with custom cabling.
  • Offering flexibility and scalability—as you integrate new cabling standards to support higher network speeds, you can simply swap existing cassettes with new cassettes that support the new standards. Your network can grow and change conveniently, without the costly, labor-intensive process of replacing channels end-to-end.
  • Reducing cable congestion—reduced cable slack means less clutter, less confusion and an easily organized, better-labeled cabling infrastructure. You can also manage cables in any direction, be it horizontal or vertical, front or back.
  • Space-saving—you can save valuable rack space to lower data center costs by managing various port densities and speeds in a single high-density patch panel. A single patch panel can manage as many as (168) 10G ports.
  • Right-size investments—with a modular solution, you can buy and load only the cassettes you need now, while leaving room for future expansion.
Conclusion

Although modular patch panel solution provides a feasible and optimized way to migrate and upgrade your networks, ensuring users to integrate equipment with different network speeds seamlessly and conveniently. It also faces the challenge when selecting a modular patch panel solution that best fits your demand. So users should choose the right one to satisfy connectivity needs for now and future-proof network for tomorrow which would ensure a maximum return on investment.

Copper Cabling Installation Guideline

As bandwidth demands continue to rise, both copper and fiber cable manufacturers are developing fast to provide greater capacity and flexibility. Copper cabling is still preferred by many network managers because copper cables especially UTP cables (eg. Cat6 UTP Cable), are as inexpensive as optical fibers and easy to install. And the components such as patch panels, wall-plate outlets, connecting blocks are economical. Here are the guidelines for copper cabling installation which would ensure a faster and safer copper network.

Standards

The first step when planing and deploying a telecommunication infrastructure is to make sure you are following the ANSI/TIA-568-C standard. This standard will ensure that your cabling system is interoperable with any networking or voice applications that have been designed to work with that standard.

Cable Distances

ANSI/TIA-568-C standard defines the maximum distance that a horizontal cable should traverse. The tips relating to distance and the installation of copper cabling are listed below.

  • Never exceed the 90-meter maximum distance for horizontal cables.
  • Horizontal cable rarely goes in a straight line from the patch panel to the wall plate. Remember to account for the fact that horizontal cable may be routed up through walls, around corners, and through conduit.
  • Calculate any additional cable distance that may be required as a result of trays, hooks, and cable management.
  • Leave some slack in the ceiling above the wiring rack in case re-termination is required or the patch panel must be moved. Some professional cable installers leave the extra cable loop in the ceiling bundled together or looped around a hook, shown as below.
extra cable loop
Wiring Patterns

The ANSI/TIA-568-C standard releases two wiring patterns for modular jacks and plugs: T568-A and T568-B. The only difference between them is that pin assignments for pairs 2 and 3 are reversed. As for the applications and working principles, these two wiring patterns make no difference. Remember to choose the same wiring configuration on both ends.

The cable pairs are assigned to specific pin numbers. The pins are numbered from left to right if you are looking into the modular jack outlet or down on the top of the modular plug. The following picture shows the pin numbers for the eight-position modular jack (RJ-45) and plug.

Installing Guide

Many factors need to be considered before you start installing copper cabling. Even if you have adequately planned your installation, situations can still arise that will cause problems either immediately or in the long term. Here are some tips to keep in mind for installing copper cabling.

  • Do not untwist the twisted pairs at the cable connector or anywhere along the cable length any more than necessary.
  • Bridged taps are not allowed.
  • Use connectors, patch panels, and wall plates that are compatible with the cable.
  • Never splice a data cable if it has a problem at some point through its length; run a new cable instead.
  • When terminating, remove as little of the cable’s jacket as possible, preferably less than three inches. When finally terminated, the jacket should be as close as possible to where the conductors are punched down.
  • Don’t lay data cables directly across ceiling tiles or grids. Use a cable tray, J hook, horizontal ladder, or other method to support the cables. Avoid any sort of cable-suspension device that appears as if it will crush the cables.
  • If you have a cable with damaged pairs, replace it. Don’t use another unused pair from the same cable because other pairs may be damaged to the point where they only cause intermittent problems, which are difficult to solve. Substituting pairs also prevents any future upgrades that require the use of all four pairs in the cable.

With the rapid development and upgrading of Ethernet technology and the surrounding standards, the applications of copper cables also develop like PoE technology, wireless access, digital camera, LED-based power system and sensor networks. Although fiber is very popular in the data center market, the advent of 25G and 40G copper cable standards demonstrate the continuous evolvement of copper cable technology, which still has a strong presence, particularly in the area of server end access.

How to Punch Down Keystone Jacks?

Keystone jack, also known as keystone module connector, is a snap-in package used for mounting various types of low-voltage electrical jacks. It can also be used for mounting optical connectors into the wall plate or patch panel for network wiring installs. There are numerous requests for wiring diagrams or general information on how to punch down or terminate keystone jacks (Cat5e / Cat6) after running your telecom network’s cross-connect cabling. This article will cover materials needed to solve this problem. With our easy-to-follow wiring guide, you’ll have your Cat5e and Cat6 keystone jack wired, installed and ready to go in no time!

Step 1: Make sure the stripper is adjusted properly on a scrap piece of cable. The Stripper should be adjusted to only score the jacket to make removing it easier and not nick the twisted pairs. Using a Coaxial Stripper strip around 1 inch of the jacket off. Be careful not to nick the conductors as this will cause the wire to break or short out the connection causing problems down the road. Inspect all wires for damage before proceeding to step 2.

keystone jacks

Step 2: Straighten the pairs out completely and lay them over the top of the keystone jack noting the color pattern for the 568b wiring. Note: Each keystone jack is slightly different in how they are labeled and how the colors are arranged. The 568B standard is most commonly used and ends of the cable must have the same standards to communicate. We have the 3 most common keystone jack styles pictured here. The first jack pictured has the 2 standard pairs on the right, and the 2 variable pairs on the left. The A standard is the center column and the B standard is on the left. Both A and B standard applies to the right side of the jack. The solid color box with the lower right corner missing represents the solid color wire with the white stripe. The white box with the colored tip represents the white wire with the colored stripe.

Step 3: Keeping the pairs as twisted as possible press the wire into the correct groove with your thumbs. If you completely straighten the wires to run them through the jack you will risk cross talk between the pairs.

punch down tool

Step 4: Using a punch down tool to punch the wires down into the blades built into the keystone jack. The blades in the jack are designed to work with solid cable, and may not work with stranded cable. Make sure the blade is facing the outside of the keystone jack. If you reverse it you will cut the wires inside the keystone jack rendering them useless. The punch down tool should cut off the remaining pieces of the wire on the outside, but sometimes you may need to punch them down a 2nd time and wiggle the wire to it breaks clean off. Then you can install the dust covers if your keystone jack comes with them.

Keystone jacks have been widely used in data communication and LAN wiring. FS.COM offers cost-effective Cat5e and Cat6 keystone jack with RJ45 connector-style. They also provide keystone Cat5e toolless style connectors which make for a simple installation without the need for a punch down tool. Toolless keystone jacks are an ideal solution for terminating and connecting network cable. For more details, please visit www.fs.com.

D-Rings for Cable Management

In high-density data centers, disorder of cable assemblies can lead to poor system performance, difficult maintenance, unnecessary downtime, and even safety hazards. Good management will enhance your system availability and efficiency by well organizing the mass of cables. D-rings, as one of the common types of cable management products, play an important role in building an easier and safer cabling environment.

What Can D-Ring Cable Manager Achieve?

D-ring, also known as D-ring cable manager, is a basic manager that organize cables. It is commonly used individually on any suitable plat like wall or installed on cable management panel to provide easy and orderly cable routing, making it one of the most versatile cable managers on the market! Whether you’re routing cables from the front to the back of your cabinet or organizing and supporting patch cables, the D-ring cable manager will be an effective tool for your IT installation.

Types and Selection of D-Ring Cable Manager

D-ring cable managers are designed with different sizes, shapes and materials for different applications. There are mainly two types of D-ring according applications one is for vertical cable management and the other is for horizontal cable management. As for the materials, durable metal is more popular during applications. The selection of D-ring cable manager should also consider the size of a D-ring and cable count the D-ring going to hold. The following picture shows horizontal cable management and vertical cable management applications of D-rings.

D-Ring

How to Use D-Ring in Cable Management

The using and installation of D-ring cable manager is simple and easy. With screws and installing tools, you can make full use of this cable management accessory. As the above mentioned, D-ring is usually installed on cable management panels. Here will introduce how to use D-ring in vertical cable management and horizontal cable management in details.

  • D-Ring in Vertical Cable Management
    When a D-ring is used for vertical cable management, it can be directly installed on the server rack using appropriate fasteners. It can be used for both front or rear cable management providing tidy cabling appearance and easy cable adding or removing in vertical cabling environment.
  • D-Ring in Horizontal Cable Management
    The using of D-ring in horizontal cable management is more flexible and can be used with a wide range of cable management products for different applications. In most horizontal applications, D-ring is installed on cable management panels. Here introduce two of the most commonly seen applications of D-ring. The first one is using D-ring with patch panel, the second one is using D-ring with rack unit enclosures.

The following picture shows a simple example of fiber cabling using cable management panel with D-ring on the front panel, fiber patch panel installed on the IT rack and a lacing bar on the rear side. Four 24-fiber LC adapter panels are installed on the fiber patch panel. The cable management panel with D-ring is installed on the front side of this IT rack providing an organized channel for the fiber optic cables connected to the fiber adapter panels. Fiber cables connected to the rear side are supported by the lacing bar which provides cable strain relief.

panel with D-ring

Conclusion

D-ring is a small but indispensable accessory in cable management, which can promote clean and tidy cabling environment. Apart from the D-rings mentioned above, there are many other small but effective tools for cable management, such as cable ties, cable lacing bars, J-Hooks, and wire looms which are also very necessary for cable organization.

Understanding DWDM in Optical Communication

Without optical communication we might be still sending mail, going to the newsstand to buy a newspaper, sending mail and postcards and renting movies, no internet would have been possible, no digital communications as we know it.

Among the many unsung technologies that make all this possible, Dense Wavelength Division Multiplexing (DWDM) is without any doubt one of the most important. As a kind of WDM technology, DWDM has the capability to send multiple signals on the same fiber, using different wavelengths. DWDM devices combine the output from several optical transmitters for transmission across a single optical fiber. At the receiving end, another DWDM device separates the combined optical signals and passes each channel to an optical receive. One of the nice characteristics of the optical fiber is that different channel can travel one close to the other with very little, almost negligible in most cases, crosstalk. Thanks to DWDM, we’re now able to pack 10 TBits/s of traffic per single fiber and send it more than 1000Km.

DWDM started as high end transport technology, but made its way to regional and metropolitan network and finally into transceivers. Several generation of DWDM transceivers have already been released (XENPAK, X2, XFP, SFP, SFP+), providing networking equipment not only with the capability to transport a huge amount of data with a single fiber, simplifying cabling and reducing cost, but also reducing the number of equipment needed. Before, if an operator wanted to connect 2 switches located some tens of kilometers apart, it needed non-coloured optics on the switch, connected with the same kind of optics on the transport system transponder shelf, this last piece of equipment did the conversion from non-DWDM wavelengths to DWDM wavelengths before they were optically multiplexed and transported over the DWDM link, the opposite process at receiving site. With DWDM transceivers directly on the switch, they can be connected directly to the optical multiplexing gear. It is evident that this solution has numerous advantages.

DWDM

If it is clear that DWDM optics come with great advantages, but the device is more complex and more optical variables comes into play. With uncoloured optics everything is pretty simple , they come with a “distance” tag attached (10km, 40km, 300m), power budget is pretty much the only parameter that the end user should care about. With DWDM there is no specific target distance power levels are of course still important, but other parameter, such as OSNR (optical signal to noise ratio) and CD (chromatic dispersion) come into play, in fact, often specifications are given in the form of a combination of the three mentioned parameters.

An optical signal travelling on a fiber experiences an attenuation of about 0.2dB/Km, so if you want to transmit it for long distances it needs to be amplified along the way and probably more than once. Erbium doped fiber amplifiers (EDFAs) do exactly this, but, at every amplifying stage, noise is added to the signal. The longer you want to go, the more amplifiers you need, the noisier the signal at the end of the line. Below a certain OSNR, which depends on the device to device, becomes impossible to detect the signal with an acceptable bit error rate.

DWDM is ready made for long-distance telecommunications operators that use either point-to-point or ring topologies. It provides ultimate scalability and reach for fiber networks. Without the capacity and reach of DWDM systems, most cloud-computing solutions today would not be feasible. Establishing transport connections as short as tens of kilometers to enabling nationwide and transoceanic transport networks, DWDM is the workhorse of all the bit-pipes keeping the data highway alive and expanding.