Category Archives: Copper Networks

Among so many categories of copper cables such as Cat5e, Cat6, Cat6a, Cat7, even Cat8, what kind of cables should you choose? And how to make Ethernet patch cables by yourself? For more copper networks information, check the following articles.

Things You Should Know About Wireless Access Point

A wireless access point (WAP or AP) is a hardware device or configured node on a local area network (LAN) that allows wireless capable devices and wired networks to connect through a wireless standard, including Wi-Fi or Bluetooth. A wireless access point acts as a hub of traditional wired network, and a bridge connecting wired and wireless network. An access point connects to a wired router, switch, or hub via an Ethernet cable, and projects a Wi-Fi signal to a designated area. Wireless access points may be used to provide network connectivity in office or family environments, covering dozens of meters to hundreds of meters. Most APs use IEEE 802.11 standards.



Wireless access points can be divided into two types: Simplex AP and Extended AP.

A simplex AP functions as a wireless switch, only transmitting radio signal. When a simplex AP works, it transmits network signal through twisted-pair and converts electrical signal into radio signal after compiling, forming the coverage of Wi-Fi shared Internet access.

An extended AP, commonly known as a wireless router, is mainly applied to Internet access and wireless coverage. Through a wireless router, the share of Internet connection in home Wi-Fi sharing network, as well as wireless shared access of ADSL (Asymmetrical Digital Subscriber Loop) and community broadband can be realized. From security, an access point is different from a wireless router, in that it does not have firewall functions, and will not protect your local network against threats from the Internet.

Difference Between Access Point and Wireless Router

From the appearance, they look almost the same and hard to tell, but they do have subtle differences. A simplex wireless AP usually has a wired RJ45 network port, a power interface, configuration port (USB port or configuration via WEB interface), and fewer indicator lights; while a wireless router has four more cable front-end ports. In addition to a WAN port for connecting higher-up network equipment, four LAN ports can be wired in internal network, and a router has more indicator lights than AP.



AP plays the important role of relay, which amplifies the wireless signal between two wireless points, and enables remote clients to receive stronger wireless signal. For example, if an AP is put in place A, and there is a client in place C which is 120 meters away from place A, it can be seen that the signal from A to C has been weakened a lot. If an AP is put in place B (60 meters between A and C) as a relay, the signal of client in C will be effectively enhanced, and the transmission speed and stability can be ensured.


Another important function of AP is bridging, which is to connect two endpoints and achieve data transmission between two wireless AP. AP is also bridged to connect two wired LANs. For example, there is a wired LAN made up of 15 computers in place A, and wired LAN made up of 25 computers in place B, but the distance between A and B is very far, over 100 meters, and there is no possibility through wired connection, then how to connect the two LANs? AP is needed in both place a and place b to bridge them so that data transmission can be achieved.

The last function is “master-slave mode”, which can achieve one point to multipoint connection. “Master-slave mode” is widely used in connection between wireless LAN and wired LAN. For example, place A is a wired LAN made up of 20 computers, place B is a wireless LAN made up of 15 computers, and B has a wireless router. If A wants to be connected to B, an AP is needed in A. Initiate the “master-slave mode” and connect AP to the router in A, so that all the computers in A can connect to B.


Most businesses and homes today rely greatly on the wireless access point (WAP) for data transmission and communication. Wireless access point does make our life more convenient. These devices avoid a mess of wired Ethernet cables. Besides, a company, family or school often has to install wired cables through walls and ceilings, while wireless network needs no cables, which contributes great mobility to users.

Cat6 and Cat6a Copper Cable Differences

As the data speeds increase from Fast Ethernet to Gigabit Ethernet, cables for the network connection are also required to be improved. Cat6 and Cat6a are two kinds of copper cables for Gigabit Ethernet. “A” is short for “augmented”. Cat6a is an enhanced Cat6 cable. Do you know which you should use, Cat6 or Cat6a? Could these two categories replace each other? Now this article will tell some of their differences from several sides.



It’s not difficult to identify Cat6 and Cat6a cables from appearance. If you look at the jacket carefully, you will find the identifiers printed as Cat6 and Cat6a. You can also distinguish these two cables from thickness. Cat6a cables are much thicker than Cat6 cables.


Copper cables have shielded twisted pair (STP) and unshielded twisted pair (UTP). STP cable means there is one or more additional jackets surrounding the inner twisted wire pairs for insulation. The shielding is beneficial for protecting cable from electromagnetic interference (EMI). (For more information about STP vs. UTP difference, you can refer to my blog “STP vs. UTP, Which One Is Better?” .) Cat6 and Cat6a cables also include these two types. Though shielded Cat6 cables are available in the market, unshielded versions are easier to get. On the contrary, shielded Cat6a cables are more common.

Transmission Distance

Cat6 cable can support the transmission distance up to 100 meters at the data rate of 10, 100, 1000 Mbps. But it can support only 55 meters at the speed of 10 Gbps when crosstalk is in an ideal situation. What’s worse, the transmission distance can only reach 33 meters when the crosstalk is high. So the lengths of Cat6 cables are influenced by the network speed and crosstalk conditions. While Cat6a cables can support the distance over 100 meters at the speed of 10 Gbps.


Take Fiberstore as an example, the average cost of 1m Cat6 cable is about 1.00 US$ and more than 3.00 US$ for 1m Cat6a cable (cables maybe more expensive on other sites.). The more cables you purchase, the bigger the price difference will be. And the price difference is not only caused by the cable. Other matched connection components should also be considered.


As mentioned above, Cat6a cable is thicker and heavier than Cat6 cable. Cable trays can not hold as many Cat6a cables as Cat6 cables. When laying cables on the trays, you should better not bend cables too much as this can damage the wiring and influence network performance. The minimum radius that a cable can be bent without damaging is called the bend radius. The lower the bend radius, the more you can bend the cable. As Cat6a cable is bulkier than Cat6, Cat6a cable has a larger bend radius than Cat6 cable.

Which One Should You Buy?

Although Cat5e cable can meet the current needs in your home or office, higher bandwidth will be required in the near future. So you should upgrade your network with Cat6 or Cat6a cables which can provide greater bandwidth. At that time, you need to figure out which one to buy. If you install cables in a small room or business offices where cables might get close to one another, then Cat6a is better than Cat6 due to the alien crosstalk. Cat6 cables especially the unshielded cables, are much more prone to alien crosstalk than Cat6a, which uses superior insulation to protect its wiring.


From this article, you can make a clear identification of Cat6 and Cat6a cables. When you plan to purchase cables, you need to consider their differences like shielding, transmission distance, cost, durability, etc. Hope you can choose the suitable cable and build a high performance network.

STP vs. UTP, Which One Is Better?

When you prepare to buy Ethernet cables, you have to choose between STP (shielded twisted pair) and UTP (unshielded twisted pair) . That’s really difficult to decide if you don’t have enough knowledge of these two kinds of cables. Do you want to know more? Read this article and you will find the answer.

Why Are There STP and UTP Cables?

In data communication, electromagnetic interference (EMI) exists in cables. EMI, also called radio frequency interference (FRI), is a disturbance. This disturbance is caused by an external source affecting an electrical circuit by electrostatic coupling, electromagnetic induction, or conduction. The external source can be natural or man-made. For example, the natural sources include the sun, thunder storms, etc., while the man-made sources are vehicle ignition systems, cell phones, etc. EMI may cause data error and influence the transmission quality of cabling systems. In consideration of decreasing or avoiding EMI, shielding is one of the methods applied to protect cabling systems.

What Are STP Cables?

STP cable has a shield inside which is composed of copper tape, a layer of conducting polymer or a braid (made of copper or aluminum mostly). There are different types of shielding, such as braided shield, foil and screening. That makes different levels of shielding, including STP, SSTP (screened shielded twisted pair), FTP (foil twisted pair). The shield can be applied to each one of the pairs in a cable or to all pairs together.


Advantages of STP Cables

First, the shield of STP cables can reduce EMI. It’s good for increasing data transmission quality in buildings containing microwave equipment, HVAC (Heating Ventilation Air Conditioning) systems or radio transmitters. It blocks interference generated from devices such as power tools and vacuum cleaners. Although UTP cables are still able to reduce interference, their performance is not as good as STP cables.

Second, STP cables can reduce crosstalk with proper installation and maintenance. STP cables can resist signals from passing through the outer coating and entering nearby wires by accident because of the special cable constructure. STP cables are quite necessary for dealing with crosstalk especially when your building contains numerous network devices.

What Are UTP Cables?

UTP cables don’t have shielding to reduce interference. UTP cables reduce EMI through the way that the pairs are twisted inside the cable. Thus, UTP cables are lighter and thinner than STP cables.


Advantages of UTP Cables

First, easier to install and maintain. UTP cables contain no shields and they are thinner than STP cables, which is easier for cable installation and maintenance, particularly in limited space. While the shields of STP cables are quite fragile and rigid. If the shield suffered damage, cabling systems are likely to be affected by interference. What’s worse, it’s not easy to be repaired and needs special handling.

Second, more flexible. UTP cables are comparatively lighter. On one side, it makes the installation, transport and maintenance work easier. On the other side, it makes UTP cables more suitable to be used in narrow space.

Third, fewer cost. UTP cables are cheaper than STP cables. So are the related hardware. Besides, as mentioned above, UTP cables are easy to install and maintain. You don’t have to spend too much money on maintenance since UTP cables don’t rely on an outer shield. So they are beneficial to save you investment on installation and maintenance.


Due to different characteristics, the two types of cables are used in different environment.

STP cables are often used in situations nearby equipment causing EMI. For example, airports, medical centers and factories have lots of machines that can produce interference, so STP cables are typically applied. STP cables are also useful when cables must be run next to fluorescent lights, microwave ovens or powerful motors. What’s more, STP cables can be used in outdoor settings. Some people connect outdoor surveillance cameras to STP wiring. In that way, the video feed can avoid the interference generated by vehicles and power lines. And it can stop criminals from using jammers to interrupt communications between cameras and indoor monitors or recording equipment.

UTP cables are suitable to be used in offices and homes. They are less expensive than STP cables. So if the interference or crosstalk is not your main concern, you are suggested to choose UTP cables for saving you cabling cost. Remember not to select UTP cables if your place is full of powerful magnetic fields which can slow down the network speed or cause the network failure. Therefore, you’d better carefully evaluate the potential sources of interference.


Choosing the right cable can improve your network performance and extend the life span of your equipment. Before making the decision, it’s important to get well known of STP and UTP cables. You must know exactly each one’s advantages and application areas. If you need better anti-interference capabilities, you can select STP cables. If you put cost as the first factor, you may choose UTP cables. For both kinds of cables, you can find in FS.COM. Any question, please contact us via

Which Ethernet Cable Should You Choose?

Ethernet cable is one of the media transmitting signals to a home or business network place. Although the world is going wireless today, Ethernet cable is still used in many situations due to its advantages of fast speed, high reliability and security. But when you decide to buy the Ethernet cables, you will get confused about which category to choose. This article will discuss how to make your decision among these Ethernet cables like Cat5, Cat5e, Cat6 and Cat7.

Ethernet Cables Types
Cat5 Cable

Cat5 cable can handle 10/100 Mbps speed (Fast Ethernet) at the bandwidth up to 100 MHz. Cat5 cable is the oldest of these three kinds of cables. Over the years, Cat5 cable was used majorly in networking especially when pairing older routers, switches and other myriad networking devices. Nowadays it’s not used for too many installations. But it can support gigabit speeds if the cable is shorter sometimes.


The letter “e” means “enhanced”. As the name says, Cat5e is an improvement on Cat5 cable. Currently it’s the most popular cable used in new installations. It’s designed to support 1000 Mbps or gigabit speed. It can also greatly reduce the crosstalk. The crosstalk is the interference existing sometimes between wires that are sealed inside a cable. With this feature, Cat5e can better keep signals on different circuits or channels from interfering with each other. In a word, Cat5e cable can provide a faster, more reliable and steady network than Cat5. And Cat5e is also compatible with Cat5 cable.


Cat6 is an improvement over Cat5e. It has more sophisticated constructure and can support the speed up to 10 gigabit and the bandwidth up to 550 MHz over long distances. Cat6 is a good choice for those who want to install future-proof network. But Cat6 cable is not very good for the applications at home. This kind of cable is recommended for large organizations which deal with pretty bulk files.


Cat7 cable is designed to be used in Gigabit Ethernet and can support bandwidth up to 600 MHz. It greatly improves the capacity and reliability of Cat6. Another big advantage of Cat7 is the shielding of its twisted pairs, which significantly improves noise resistance. Cat7 is thought as the most durable and has a longer lifespan than Cat 5 and Cat 6. It’s the best choice for future use. But it’s comparatively expensive.


Which One Should You Choose?

First, you need to think about the question seriously how you like your current network speed. If you are satisfied with the current network speed, you don’t need to upgrade it. But if your hardware can handle 1 Gigabit and you are still using Cat5 cable, then you should better upgrade your Ethernet cables. You may choose Cat5e cable which is enough for your network needs. Or you can select Cat6 cable.

Second, you should know that network speed is not the same to internet speed. There is a chance that even though you upgrade your Ethernet cable, your internet speed won’t change too much. As it’s affected by many other factors. However, upgrading networking cables have a tremendous effect on file transfer speeds between computers. So to emphasize, when buying Ethernet cable, you should also consider your hardware compatibility.


From this article, you can find it’s not very hard to decide which kind of Ethernet cable to use. To make the right decision, it depends on your situations. Usually Cat5 or Cat5e cable is enough for home network use. If you transfer lots of data over your network, then you can upgrade your network cables from Cat5 to Cat5e or Cat6 to guarantee your network speed. But if you are satisfied with your current network speed, you don’t need to replace Cat5 with other cables. Of course, the cost is also an important factor. So if budget allows, Cat7 is a nice choice. At last, no matter what kind of cable, please notice that the Ethernet cable should be less than 100 meters in length to achieve higher efficiency.

How to Make Your Own Ethernet Cables?

Ethernet patch cables are indispensable for network. However, Ethernet patch cables are more expensive than bulk cables and the pre-terminated lengths are not always that you need. So it’s quite necessary to know how to wire Ethernet cable by yourself. This article will show you detailed steps of making your own Ethernet patch cable.

Materials You Need
Bulk Ethernet cable

Usually people will choose Cat5e cable. Cat5e cable is a little different from Cat5. It can handle data rate up to 1000Mbps. Cat5e is suitable for Gigabit Ethernet and experiences much lower levels of near-end crosstalk (NEXT) than Cat5. So in most applications, Cat5 has been superseded by Cat5e. Except Cat5e, you may also choose Cat6 cables which have better performance. Cat6 cable has twice the bandwidth of Cat5. It’s ideal for supporting 10 Gigabit Ethernet. Select the cable type and then buy the lengths of the cable you need.

RJ45 Connectors for Cat5e or for Cat6

RJ45 connectors are often used for telephone and network. RJ45 connectors include a variety of types for Cat 5e or Cat6, such as shielded, strain relief boots, 2 prong or 3 prong, etc. Whatever, you need to select the one suitable for your application. FS.COM provides plenty of RJ45 connectors meeting a high standard of safety quality.


RJ-45 Crimping Tool

RJ45 crimping tool is designed to quickly, strip, crimp and cut the wires in an easy operation. FS.COM supplies various types of high quality crimping tools. With this kind of tool, you can get precise and reliable terminations every time.


Steps for Wiring Ethernet Cable
Step 1. Strip Outer Sheath

Use your stripper on your crimping tool to strip 1 inch (2.5 cm) sheath from the end of the cable. Insert the cable into the stripper portion of the crimping tool and squeeze it tight. When squeezed, rotate the crimping tool around the cable a full 360°. At last, pull away and the sheath will be stripped. If you break the internal twisted wires by accident, just cut the broken wire and strip again. So when you measure the cable length, you should better leave spare inches in case things happen like this.

Step 2. Untwist and Arrange Wire

After stripping the sheath, you can find 8 color-coded wires inside. Then you need to untwist the internal wires and arrange them into a proper wiring scheme for RJ45 connector. There are two kinds of color codes standards: T568A and T568B. The color order is important to get correct. No matter which standards you choose, you should arrange the color-coded wires in the same order on both sides. Here recommend you T568B color-coded wiring. The following are about pins and colors used in T568B standards.


Step 3. Insert the wire into RJ45 connector

Before insert the wire into RJ45 connector, you need to cut down the wire to fit in the connector. Bring the wires together and cut them down in an even line with the cutting tool on the crimping tool. Then insert the wires into the connector in the right order. Ensure each wire fits into each groove in the connector. The wires should be inserted until the sheathing is inside the connector, just beyond the crimp portion of the connector.


Step 4. Crimp

Put the connector into the crimping tool carefully until the connector can’t go in any further. Squeeze the crimping tool very tightly and release. Then squeeze the the crimping tool again to make sure that all of the pins are pushed down on the connector. When finishing crimping, check that if all pins are all crimped down. If the pins are all down, tug the connector slightly to make sure that it is securely attached to the wire.


Step 5. Test

Before installing the cable, you should better take a test with an Ethernet cable tester. If the Ethernet cable doesn’t work, look closely at each end and see if you can find the problem. Usually the problem is caused because a wire ends up in the wrong place or one of the wires makes no contact or poor contact. You should also check if the color is in the right order. If the color order is wrong, then cut the end off and start again.


Sure, you can buy Ethernet cables from the store directly. But if you need to make your own cable with special lengths, then you are lucky to read this article. Remember that the Ethernet cable should be no more than 100 meters or 328 feet. Because the cable performance will be influenced by the over length. For bulk cables, RJ45 connectors, crimping tools, and network testers, etc., you can get all from FS.COM. Hope you can make your own Ethernet cable successfully.

How to Distinguish T568A and T568B of RJ45 Ethernet Cable Wiring?

Ethernet cable can be easily found in our daily life. Ethernet cable is color-coded if you look at it carefully. Color-coded wiring sequences exist as a cabling industry standard. Thus, cabling technicians can save a lot of time of doing cable termination on both ends by following others’ work without guessing or deciphering the function and connections of each wire pair. This article will tell the T568A and T568B standards that the Ethernet cable jack wiring follows.

What Are T568A and T568B Standards?

RJ45 conductor data cable contains 4 pairs of wires. Each one consists of a solid colored wire and a strip of the same color. There are two wiring standards for RJ45 wiring: T568A and T568B. T568A and T568B are the two wiring standards for RJ45 connector data cable. T568A was specified by TIA/EIA-568-A wiring standards in 1995. Later it was replaced by the TIA/EIA 568-B standard in 2002 and has been updated since. Both standards define the T568A and T568B pin-outs for using unshielded twisted pair cable and RJ45 connectors for Ethernet connectivity. These two standards and pin-out specification appear to be related and interchangeable. But they still have differences and should not be used interchangeably.


RJ45 Color-Coded Scheme

RJ45 cables have 8 color-coded wires and the plugs have 8 pins and conductors. Eight wires are used as 4 pairs, each representing positive and negative polarity. The following figure shows pin and colors used in the T568A and T568B standards.


Straight-through and Cross-over Connections

The wiring standards T568A and T568B are used to create a cross-over cable (T568A on one end, and T568B on the other end), or a straight-through cable (T568B or T568A on both ends).

Straight-through cables are used to connect computers to a Ethernet switch. The RJ45 cable uses only 2-pairs of wires: orange (pins 1, 2) and green (pins 3, 6). Pins 4, 5 (blue) and 7, 8 (brown) are not used. Straight-through cable connects pin 1 to pin 1, pin 2 to pin 2, pin 3 to pin 3, and pin 6 to pin 6.


Cross-over cable is used to network two computers without a Ethernet switch (hub). Cross-over cable connects pin 1 to pin 3, pin 2 to pin 6, pin 3 to pin 1 and pin 6 to pin 2. This kind of cable is used to connect TX+ (transmit) to RX+ (receive), and TX- to RX-. The unused pins are generally connected straight-through in both straight-through and cross-over cables.


Which Standard Should You Choose?

Actually there is no electrical difference between the T568A and T568B wire sequences. So it’s hard to tell which one is inherently better. The difference between the two is the position of the orange and green wire pairs. It is preferable to wire to T568B standards if there is no pre-existing pattern used within a building.

In fact, both standards are acceptable in most cases. You can use either one as long as you’re consistent. T568B is the standard followed by the majority of Ethernet installations in the United States for RJ45 color code. It is the more common standard used when cabling for businesses. While T568A is the majority standard followed by European and Pacific countries. It is also used in all United States government installations. So when you face the selection, you may make the decision on the country you work in and what types of organizations you install for.


T568A and T568B are the two wiring standards for RJ45 connector data cable specified by TIA/EIA-568-A wiring standards document. Color-coding is part of the standards. If modifying the Ethernet cables improperly, signal loss of network connectivity can be caused. So please insure all connectors and cables are modified in accordance with standards when you do cable terminations.

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.


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.

Products Used in the Physical Layer

The Physical Layer, as the Layer 1 of ISO OSI Systems communications model where the mechanical and electrical specifications of physical network interface are defined. The physical network interface is considered passive network elements because they do not generate or alter data units traveling across the network. Network elements defined by the Physical Layer include (among others): Network transport media (cables) and connectors.

Network Media Types

Network media types used in Data Center today are copper and fiber optic cables.

The following copper cables are available: Cat 1 to Cat 5, Cat 5E, Cat 6, Cat 6a, Cat7 and Twinax cables. Twinax copper cable with two conductors in a coaxial cable, which is slowly wrapped around each other; originally designed to replace RS-232 and has been redesigned for high-speed computer applications under 10 meters.

Fiber optic cable utilize light for data transmission, rather than electrical current on copper cables, Fiber optic cables have many advantages, for example, the are many times lighter and have substantially reduced bulk, no pins, a smaller and more reliable connector reduced loss and distortion, and are free from signal skew or the effects of electro-magnetic interference.

Cable Connector Types

Copper cable connectors. Currently, there are two copper connector standards are in use, RJ-45 and MRJ-21.

RJ-45: The most popular Ethernet connector in use nowadays. MRJ-21: Used in Brocade’s netlron MLX product family, provides 1GbE connectivity of up to 6 ports by the RJ-45 patch panel or RJ-45 connectors. It is a high-density, high-speed copper cable.

Optical cable connectors. Optical cable connector structure can be divided into: FC,SC, ST, LC, D4, DIN, MU, the MTP,MPO and so on in various forms.

Transceivers Are Either Copper or Optical

Copper transceivers, copper medium usually does not require any transceivers, as they are a part of the interface module. However, few of Brocade’s products use a copper SFP with an RJ-45 female connector for 1 GbE connectivity over copper medium, or XFP copper transceiver for 10GbE connectivity over CX4 copper. Figure 1 is a 1000BASE-T Gigabit Ethernet Full Duplex RJ45 100m Copper SFP Optical Transceiver.

copper sfp

Figure 1. Copper SFP Optical Transceiver

  • XFP 10GBASE-CX4: Uses a CX4 connector to provide a connection to up to 15 meters over CX4 grade copper cable.
  • SFP 1000BASE-TX: Uses a RJ-45 connector to provide a connection to up to 100meters over Cat5e or higher copper cable.
Optical transceivers.

The following optical transceivers are available: (Figure 2 is a CWDM SFP 40km Single-Mode Optical Transceiver)

cwdm sfp

Figure 2. CWDM SFP Optical Transceiver

  • SFP: Small form-factor Pluggable. Supports 100Mbps and 1Gbps Ethernet.
  • SFP+: Small Form-factor Pluggable Plus. Looks are physically identical to the SFP port but support higher speeds. Supports 10Gbps Ethernet. Might also support SFP transceivers.
  • XFP: 10 Gigabit Small Form-factor Pluggable. Supports 10Gbps Ethernet.
  • XENPAK: XENPAK transceiver is a hot-swappable I/O devices that plug into 10-Gigabit Ethernet module ports. The XENPAK transceiver is available in either optical or copper interfaces. It is used in typical router line card applications, storage, IP network and LAN.
  • X2: X2 transceiver is a standardized form factor for 10 Gb/s fiber optic transceivers that is used for data transfer rates from 10.3 Gb/s to 10.5 Gb/s. X2 transceiver is used in datacom optical links only (not telecom), and they are smaller than old generation XENPAK transceiver.
  • GBIC) Transceiver: A gigabit interface converter (GBIC) transceiver can send and receive data, which is to digitally convert media between a gigabit Ethernet network and a separate fiber optic based network.

SFP+ Twinax cables are copper cables with two SFP+ transceivers attached on either end. They are also known as Direct Attach Cables (DAC). Using SFP+ Twinax cable is significantly cheaper than connecting devices using two 10Gbps fiber optic transceivers over fiber cable. There are two types of SFP+ Twinax cables: active and passive. SFP+ Twinax cable provided by is available in lengths of 1m, 2m, 3m, 5m.

In addition, all those copper or optical products used in the Physical layer can be found in

The Core Technology Of WIRING

1. High-precision Optical Time Domain Reflectometer(ODTR)

OTDR Price technology through sending a test signal in the measured line while monitoring signal in the line of reflection phase and intensity. If the signal through the cable encounter mutation of an impedance, part or all of the signals will be reflected back, the reflected signal delay, size and polarity indicate the discontinuity position and feature of the special impedance in the cable.

2. Split Pairs

UTP(Unshielded Twisted Pair) cable is two insulated Copper Ethernet Cable twisted together to each other by a certain density, which reduces the degree of signal interference, each wire in the transmission of radiation waves are offset by radio waves from the other line.

The so-called split pairs is the original two pairs are opened and yet again to reform a new pair. Because when this failure occurs, the end-to-end connectivity is good, so use a multimeter or hand tool such tools can not check it out. Only with a dedicated cable tester to check it out. Since crosstalk on the related lines of no kink, so online pairs when signal through will produce a high near-end crosstalk (NEXT).

Split pairs normally also be used, but often crosstalk index is large, only to run in the 10M application, can not achieve the 100M application.

3. The Standard Twisted Pair Terminations

Twisted pair eight lines are inserted into the plug (or termination) according to the standard. There are two termination criteria: EIA/TIA T568A/T568B, no essential difference between them, but the difference between color. The natural problem of termination is to ensure that: 1, 2 are a pair; 3, 6 are a pair; 4, 5 are a pair; 7, 8 are a pair. Note: Do not one cable end with T568A, but the other end with T568B. The mix use of T568A/T568B is a special connection method of cross connection. Projects more use T568B wire method.

In Ethernet, Pin1, Pin2 is a twisted pair responsible for network data transmission, Pin3, pin6 is a twisted pair responsible for network data reception, so 1, 2 a pair, 3, 6 a pair, 4, 5 a pair, 7, 8 a pair, it is a must, and not 1, 2, 3, 4, 5, 6, 7, 8 pairs, so called split pairs, will lead to serious signal leakage.

4. Wire Map

Ware Map: This is to confirm the integrity of link connection, mainly to check each pair of 8-core Twisted Pair Cable whether meets the required standards EIA/TIA- 568A/568B, whether the wire at both ends of cable is matching. If wrong, there are five cases include open circuit, short circuit, crossed pairs, reversed pair and split pairs.

● Open circuit: refers to the phenomenon of line off, generally due to bad crystal head cable connection, common with the cable test equipment can locate the fault point.

● Short circuit: refers to one or more wires touch each other in a metal core, resulting in a short circuit.

● Crossed pairs: refers to wire at both ends error in the routing process, which is one end with 568A and the other end with the 568B, usually such wire method used in network equipments level, or network cards connection, but as a general wiring to say, as long as the two ends of the wire method consistent, as for the module wire method can refer to the color above.

● Reversed pairs: this error is due to both ends of a pair line connected to the positive and negative error, is generally believed that the odd line number for the positive electrode, the even line as the negative electrode, for example, 568B Pin1 orange white lines to the first pair of positive, Pin2 Orange Line is negative, it can form a direct current loop, reverse connection is positive and negative confused in the same pair line.

● Split pairs: this is one of the common wire error, which is not strictly comply with wire standard, it is specified in the standard that 1, 2 is the first pair, 3, 6, is the second pair, if 3, 4 into the second pair will cause large signal leakage, which produces NEXT (near end crosstalk), this will cause the user’s Internet difficulties or indirect interrupts, especially in the 1000Mbps network it is particularly obvious.

The Troubleshooting Of Fiber Optics

Fiber optics once just meet the needs of high performance systems, but now it has widely spread in various types of networks. If you are familiar with Network Cabling, then you will soon find that fiber is a kind of something completely different. Not only because of its installation process is quite different with copper wiring, and troubleshooting methods also have very big differences. Compared with copper wire, fiber optics is more fragile, so there will be some potential failures exist when use.

The Most Common Troubleshootings In Fiber Optics

Any network professionals who have done network troubleshooting are clear that this is a complex process. So know where to start looking for faults is very important. Here are some of the most common fiber failures and the possible factors cause these faults, the information will help users to predict the network faults with bases.

Fiber break is usually due to external physical extrusion or excessive bending;

Transmission power shortage;

The Optical fiber laying distance is too long may cause a loss of signal;

Connector damage may result a loss of signal;

Fiber Optic joints and connectors faults may cause a loss of signal;

The excessive use of fiber optical joints and connectors may cause a loss of signal;

Fiber patch panel or splice tra connection failure;

Generally speaking, if the connection is completely unreasonable, then it may be fiber breakage. But if the connection is intermittent, may be the following reasons:

Poor junction levels or multiple junction times cause serious optical attenuation;

The dust, scratches, fingerprints, humidity and other factors damage the connector;

The transmission power is too low;

Connector errors in the Distribution Cabinet.

Collecting Information

Collecting the fault performance and the basic information of possible causes. Using any available means, the key of troubleshooting is to get valuable information by asking the right questions.

The following are some of the problems should be first asked.

If anyone had moved the fiber (dismantling or reconnect) or moved the PC recently?

Find out whether recently PC is disconnected or be moved is very important. If the fiber optical cable is disconnected from the PC, then it is likely that the cable simply has not been properly connected, or problems occur when reconnection, or the fiber may damage when disconnect.

Whether the device recently was moved?

Most copper network failures are caused by someone walking too fast to the original sticking wall table, or cleaners accidentally move the table to do vacuum cleaning. Moving the table without unplug the network cable, the cable is likely to be excessive dragged, or is held down by table or folded. If such action would damage to a copper wire, then you can imagine what consequences will be brought to the fiber, as it is made ​​of glass.

The vast majority of users are not clear that Fiber Optics Cable will break in the situation of stepped on or bend too much.