Q1:What is Structured cabling system? Answer:
A structured cabling system is a set of structured cabling system and connectivity products that integrates the voice, data, video application in a building. A structured cabling system should be designed in accordance with international standards will ensure predictable performance across abroad range of connected equipment. Structured Cabling System refers to all of the structured cabling and connecting components installed in a logical and hierarchical way. The basic principle of structured cabling is to flood wire a building offering a three meter square grid of useable floor space for each user.This area is defined as a work area accommodating a minimum of one data outlet, one voice outlet and two 13A power outlets.
The original Standard governing the structured cabling system was the Commercial Building Telecommunication Wiring Standard EIA/TIA 568, July 1991. This has now been superseded by an International Standard ISO/IEC 11801 which has similar recommendations to the above but also includes a new chapter on Link Performance. This classifies a link that will provide the minimum transmission performance required to support an application within the same class.
A structured cabling system provides a flexible and cost effective ways of transmitting voice and data. Structured cabling system allows moves changes and upgrades to be made with the minimum amount of disruption just by making reconnection of the wiring.Leading the markets with the highest-quality connectivity products on the market, we have developed a complete end-to-end structured cabling system.If you want to get more information of structured cabling system, please read the main index for structured cabling system.
Q2:What are the major components of a Structured cabling system? Answer:
A structured cabling system consists of outlets, which are usually supplied as either one or two RJ45 connectors mounted in a standard single gang faceplate, or as single snap in modules which can be fitted into surface mount boxes or single/double gang faceplates.Each user outlet is connected to a hub using a twisted pair cables, which is named as the Horizontal Cabling. The structured cabling system can be either unshielded, known as UTP (Unshielded Twisted Pair) or shielded, known as STP (Shielded Twisted Pair) , SCTP (Screened Twisted Pair) or FTP (Foiled Twisted Pair).structured cabling system is connected to the back of the user outlet by means of a connector.The maximum length of cable between the hub and any outlet must be 90 metres or less for complying to EIA/TIA and ISO standard. The standards allow a further 10 metres for connecting patch cords, making a total distance of 100 metres or less.
At the hub, the 4 pair cables from the user outlets are terminated on patch panel. These patch panel usually have IDC (Insulation Displacement Connection) connectors on the rear for terminating the horizontal cables,and provide an RJ45 presentation on the front for patching. Patch panels are usually mounted in wall mounted or free standing 19 inch racks. RJ45 patch panels usually come with 16, 24, 32, 48 or 96 connectors. The patch panel provides 110 style, 8 pin modular connectors which are rack mounted to allow cables to be neatly punched down. Patch panel and cross connect hardware allow for:
* means to connect station cables with jumper cables.
* connection of active equipment to the UTP network.
* identification of circuits for structured cabling system management.
* An access point for circuit testing and monitoring.
* An access point for reconnection of the wiring within the network.
The hubs are connected together back to the main equipment room using backbone cables, which can either be copper or optical fibre cable. In most structured cabling system, multicore optical cables ( usually 4 - 12 cores ) are used for the data backbone cables and Multipair ( usually 25 , 50 or 100 ) copper cables are used for the voice backbone cables.
The equipment racks and cabinets usually also contain active equipment for the data network. Depending on the equipment used, the data channels may be presented in one of two different ways.
Each data channel on the equipment may be fitted with an RJ45 connector, so that channels can be patched directly to the patch panels terminating the horizontal cables. Alternatively, the equipment may be fitted with Telcoconnectors, these are 25 pair connectors each of which carries several (usually 12) data channels. Even though the IEEE 802.3ab Gigabit Ethernet specification has released and applications groups are turning their attention towards next generation solutions, there is still a great degree of uncertainty as to the capability of todays telecommunications cabling systems to support tomorrows high bit-rate applications. Fortunately, the Telecommunications Industry Association (TIA) and International Organization for Standardization (ISO) have made great strides in the specification and clarification of the minimum structured cabling system performance criteria necessary to support these next generation applications.
Additional requirements and recommendations for category 5 cable and class D structured cabling system that are intended to supplement the existing TIA/EIA-568-A and category ISO/IEC 11801 class specifications have recently been published.These specifications address additional transmission performance characterization required by structured cabling system developers to support bi-directional and full four-pair transmission schemes (such as those utilized by Gigabit Ethernet). Table 1 identifies these new structured cabling system documents developed by the TIA and ISO technical committees.
Q3:Why do we use Wall Jacks? Answer:
If there is no wall jack, one has to get enough spare cable for allowing relocation of the workstation. In this case, he may get too much cable coiled up in every station for future purposes. With a wall jack, he can get a patch cable of the best length and replace the patch cable if there is any relocation.All the wear and tear is mainly on the cable plant.With a wall jack, cable failures are much more likely to be in the patch cables, and it is always easy to swap out a patch cable when there is any cable problem.There are actually a number of components that make up a wall jack.It comprises a wall plate and a wiring box together with an RJ-45 connector.A wall plate lets you add a label identifying the information outlet. The identification should always be the same as the label on the patch panel in the wiring closet. The wiring box is pretty much like an electrical wiring box. It provides something to affix the wall plate to and a place for some slack cable.The connectors will have an RJ-45 on the front and has a 110-style connector on the back, color-coded either with 568A or B to match the color of the cable pairs.Every wall plate should be wired the same (568A or 568B) way and must also match the style on the patch panel.
Q4:Why do we use Patch Panel? Answer:
A patch panel pr.comovides a convenient place to terminate all of the cable runs coming from different rooms into the wiring closet. Of course, one could skip the patch panel and just connect all RJ-45 connectors directly into the hub, but one may miss the following advantages¡£
You can label the patch panel so you know which room the cable run goes to. Putting the labels on the cables is tougher to read than labels on a patch panel and also there is risk of having the cable labels fall off. A patch panel is a step up from a punch-down block. It usually has a 110 style connectors on the back for the cable to run to the stations. Each of those connectors is wired to an RJ-45 on the front. The RJ-45 on the front provides a spot to plug in a patch cable that goes to the hub. The Type 110-style connectors are usually color-coded with 568A or 568B to match the color of the cable pairs.It is always essential that the style (568A or 568B ) on the patch panel matches the style of the wall plate.
Q5:Why do we use 110 punchdown block? Answer:
Punchdown block were the predecessor of patch panels. punchdown block used to be very common for 4 Mbps Token Ring and Ethernet networks, but punchdown block generally are not considered capable of supporting Category 5 cabling. This section discusses punchdown block with Type 66 connectors, and their use for telephone or Local Talk networks.
66 punchdown block is used to handle telephone cabling. 66 punchdown block solved the problem of how to connect several cable runs to each other, without going through a hub.For example, One can have only one incoming line from the phone company, but I needed to connect it to several different rooms.
A 66 block is a punchdown block with type 66 connectors. A unique feature of this 66 punchdown block was that it was prewired. Each 4 rows were connected to 4 pins on an RJ-11 (phone) connector. If you do the math, you will see that with 4 rows used per RJ-45, with a 50 row block it has 12 RJ-11 connectors and 2 rows left over.
Column 4 is commonly used as an "outgoing" column, with each row connected to a pin on a cable leading to a office drop. Column 1 is used as an "incoming" column. To wire "straight through", connecting pin 1 to pin 1, all you have to do is use a bridge clip to connect column 2 to 3 on the row for pin 1. A bridge clip is just a little metal clip just the right size to connect column 2 and 3 together. If you need to crosswire something, just connect a wire from column 2 in one row to column 3 in a different row.This neat and easy arrangement has made 66 punchdown block very popular in telephone and network cable management.
Also, notice that on an RJ-11 for telephone use, the pairs are different.
Q6:Why do we use hub? Answer:
Strictly speaking, the Ethernet hub is not part of the cable plant, but your network always require a hub. Hubs are also called repeaters, are pretty inexpensive these days.
Q7:Why do we use Patch Cables? Answer:
Patch cables is used to connect the patch panel to the hub. Always use a patch cable just long enough for connection as this reduces the cabling mess and tangle. Besides, try to use different colors of cables for the particular functions.For patch cables connecting PCs to the wall plates, just get longer length for future relocation purposes.
Q8:What is 568A standard? Answer:
ANSI/EIA (American National Standards Institute/Electronic Industries Association) Standard 568 is one of several standards that specify"categories" of twisted pair cabling systems in terms of the data rates that they can sustain. The specifications describe the cable material as well as the types of connectors and junction blocks to be used in order to conform to a category.
Q9:What is Category 5 cable or Cat 5 Ethernet cable? Answer:
Category5 Cable is also named as Cat 5 Ethernet Cable, It mainly includes UTP Category 5 cable 4 Pairs, UTP Category 5 cable 25 Pairs, FTP category 5 cable 4 Pairs and FTP category 5 cable 25 Pairs. Category 5 cable (Cat 5 Ethernet Cable) defines the performance of Cat 5 Ethernet cable infrastructure capable of supporting a network speed of 100 Mbps. Generally; this is implemented using UTP or FTP cable. The Category 5 cable/Class D Specifications guarantee data networks to perform at 100 MHz and is suitable for 10Mbps and 100Mbps data transmissions.
Q10:What are Cat 5e cables? Answer:
Cat 5e cables are the most common product in the cabling system. Cat 5e cables are also named as Cat5e bulk cables. Cat 5e cables includes both UTP Cat 5e cable and FTP Cat 5e cable. The following is a more technical description of the Cat 5e cables
The test parameter for Cat 5 cables assumes that only two of the four cable pairs will be used. ( One pair for transmitting, and one for receiving). Gigabit Ethernet uses all four pairs to transmit data simultaneously. Cat 5e cables (or Enhanced Cat 5 cables) specifies a more comprehensive series of tests to measure the effect of transmitting data on all four pairs, particularly with respect to cross talk, enabling the demands of Gigabit Ethernet to be met. Cat 5e cables provides Power Sum Characteristics that enable these increased data rates.
Cat 5e cables supports increased data rates ( presently up to 1000 Mbps) across a cabling infrastructure offering the same 100 MHz bandwidth The network will be capable of supporting higher speed protocols than Standard Cat 5 cables.
Q11:What is Category 6 & 7? Answer:
Category 6 is capable of a transmission frequency of 250 MHz and would use UTP or FTP/SFTP cable and R145 connectors. It provides an excellent platform for Gigabit Ethernet (which uses complex encoding techniques to limit the required bandwidth to 100 MHz), but also caters for future high-speed data transmission protocols using less expensive encoding schemes.Category 7 will use fully shielded cables (overall shield and individually shielded pairs) and a new connector type in order to achieve 600 MHz capabilities. Cat 6 and Cat 7 have tighter twists, which result in greater speeds.
Q12:What is Power Sum? Answer:
Traditionally Crosstalk can only been measured between any combination of two pairs within the cables. Power Sum is a way of calculating the Crosstalk on an individual pair caused by the three other pairs in the cables. This is of crucial importance for Gigabit Ethernet, where all four pairs are used simultaneously.
Q13:Why do we use Category 6 instead of Enhanced Category 5 Products? Answer:
Installing Category 6 cabling now will assure going beyond Gigabit Ethernet.
Enhanced Category 5 is currently sufficient to support data rates up to 1000 Mbps over 100 Mhz but might not be capable of supporting technologies beyond Gigabit Ethernet. Category 6 allows running on a higher frequency limit 250 MHz. This allows existing protocols to operate with more headroom and provides the infrastructure to cope with future developments in data communication technology.
Q14:What is Unshielded Twisted Pair( UTP) Cable? Answer:
As the name implies, "unshielded twisted pair" (UTP) cabling is twisted pair cables which contains no shielding. The impedance of UTP is generally 100 ohm.
Q15:What is the major UTP cable Categories? Answer:
Category 1 & Category 1 ( 1Mhz ) is mainly used for Analog voice (plain old telephone service), ISDN Basic Rate Interface Doorbell wiring.
¡¡¡¡Category 2 - Category 2 (4 Mhz) is mainly used in the IBM Token Ring networks.
¡¡¡¡Category 3 - Category 3 (16Mhz) is mainly used for 10Base-T, 100Base-T4, and 100Base-T2 application.
¡¡¡¡Category 4 - Category 4 (20Mhz) is mainly used for 10Base-T, 100Base-T4, and 100Base-T2 application.
¡¡¡¡Category 5 - Category 5 (100Mhz) is mainly used for 10Base-T, 100Base-T4, 100Base-T2, and 100Base-TX application.
¡¡¡¡Category 5e - Category 5e (100Mhz) is mainly used for 10Base-T, 100Base-T4, 100Base-T2, and 100Base-TX and 1000Base T2 application As compared to Cat 5 cable, it has improved specifications for NEXT and PSELFEXT and Attenuation.
¡¡¡¡Category 6 - Category 6 (250Mhz) is mainly used for 1000Base T2 application.
¡¡¡¡As compared to Cat 5e cable, it has improved specifications for NEXT and PSELFEXT and Attenuation.
¡¡¡¡Category 7 - Category 7 is a proposed standard that aims to support transmission at frequencies up to 600 MHz over 100 ohm twisted pair.
Q16: What is Screened Twisted Pair Cables (FTP / ScTP)? Answer:
Screened Twisted Pair (ScTP) is 4-pair 100 ohm UTP, with a single foil or braided screen surrounding all four pairs in order to minimize EMI radiation and susceptibility to outside noise. Screened twisted pair is either called Foil Twisted Pair (FTP),or Screened Twisted Pair (ScTP).ScTP or FTP can be regarded as a shielded version of the Category 3, 4, & 5 UTP cables.
Q17:What is Shielded Twisted Pair Cables (STP)? Answer:
The 150 ohm twisted pair cabling defined by the IBM Cabling System specifications for use with Token-Ring networks.The twisted pairs in 150 ohm STP are individually wrapped in a foil shield and enclosed in an ov The term "shielded twisted pair" (STP) most often refers to erall outer braided wire shield.The shielding is designed to minimize EMI radiation and susceptibility to crosstalk.150 ohm STP is not generally intended for use with Ethernet.However,the Ethernet standard does describe how it can be adapted for use with 10Base-T,100Base-TX,and 100Base-T2.Ethernet by installing special impedance matching transformers,or "baluns",that convert the 100 ohm impedance of the Ethernet transceivers to the 150 ohm impedance of the STP cable.
¡¡¡¡The various versions of 150 ohm STP cable are identified by a "Type" number.The original IBM Cabling System specifications defined STP cable Types 1, 2, 6, 8, 9 for support of Token-Ring frequencies up to 16 MHz. Later, an enhanced IBM Cabling System defined STP-A cable Types 1A, 2A, 6A, 9A for support of FDDI frequencies up to 100 MHz.The "A" suffix denotes the enhanced IBM Cabling System.Type 1 is the heavy black cable that is most commonly associated with the IBM Cabling System.It contains only 2 twisted pairs as compared to UTP and ScTP which typically contain 4 twisted pairs. Note that 100Base-T4 and 1000Base-T cannot be adapted to use STP£¬because they require a cable with 4 twisted pairs.
Q18:What is Coaxial Cables? Answer:
Coaxial cable is a type of communication cable in which a solid center conductor is surrounded by an insulating dielectric which in turn is surrounded by an outer conductor (usually a braid, foil or both). The entire assembly is then covered with an insulating jacket. Coaxial cables have a wide bandwidth and are capable of carrying many data, voice, and video conversations simultaneously.
Q19:What is Thicknet? Answer:
Thicknet is the 50-ohm "thick" (10mm) coaxial cable used with Ethernet 10Base5 networks.10Base5 is the original Ethernet system that supports a 10 Mb/s transmission rate over a 500 meter maximum supported segment length.
¡¡¡¡Thick Ethernet coaxial cabling includes a "mark" every 2.5 meters to indicate proper placement of the 10Base5 transceivers (or MAUs) used to connect stations to the network. Transceivers may be placed at any multiple of 2.5 meter intervals. This minimizes signal reflections that may degrade the transmission quality of the cable segment. The outer jacket of Thick Ethernet cables is typically a bright color (often yellow) with black bands at 2.5 meter intervals to mark valid transceiver placement points.
¡¡¡¡10Base5 transceivers are attached through a clamp that makes physical and electrical contact with the cable. They are also called "transceiver taps" because they are connected through a process known as "tapping" that drills a hole in the cable to allow electrical contact to be made. The transceivers are called "non-intrusive" taps because the connection can be made on an active network without disrupting traffic flow.
The standard allows a 10Base5 coaxial cable segment to be up to 500 meters in length. Up to 100 transceivers may be connected to a single segment at any multiple of 2.5 meters apart. A 10Base5 segment may consist of a single continuous section of cable, or be assembled from multiple cable sections that are attached end to end. If multiple cable sections are used, it can result in "impedance mismatches" that are caused by slight differences in the impedance of each cable section. When excessive, these mismatches can cause signal reflections that result in bit errors and discarded frames. Segments with multiple sections are often built with cable that comes from a single spool. This ensures each section of the cable segment will have consistent impedance since it was built by.
Q20:What is Thinnet? Answer:
Thinnet, also known as Thin Ethernet, is the 50-ohm "thin" (5mm) coaxial cable used with Ethernet 10Base2 networks, supporting a 10 Mb/s transmission rate over a 185 meter maximum supported segment length.
¡¡¡¡The Thinnet cable for 10Base 2 has the advantages of being cheaper, lighter,more flexible, and easier to install than the Thicknet cable for 10Base5.However the thin cable has the disadvantage that its transmission characteristics are not as good as the thick cable. It supports only a 185 meter maximum segment length (vs. 500 meters for 10Base5) and a maximum of 30 stations per cable segment (vs. 100 for 10Base5).
¡¡¡¡10Base2 transceivers (MAUs) are connected to the Thinnet cable segment through a "BNC Tee" connector, and not through "tapping" as with 10Base5.As the name implies, the BNC Tee connector is shaped like the letter "T".The horizontal part of the "T" includes female connectors that mate with the male BNC coaxial connectors on each end of the attaching cable sections.The vertical part of the "T" includes a male BNC connector that either computer station, or to an external thin Ethernet transceiver that is then attached to the NIC through a standard AUI cable. If stations are removed from the network, the "T" connector is removed and replaced with a "BNC Barrel" connector that provides a straight through connection.
¡¡¡¡Each end of a 10Base2 coaxial segment must be terminated with a BNC 50-ohm terminator. For safety reasons, a ground wire should connect the segment to earth ground at one point, typically at the terminator on the end of the segment.
Q21:What is CATV cables? Answer:
CATV cabling is a 75 ohm coaxial cables commonly known for transmission of Cable TV signals, but is also used with Ethernet 10Broad36 networks. CATV stands for "community antenna television".
¡¡¡¡CATV cabling is used for "broadband" transmission as opposed to the "baseband" transmission used by all other Ethernet physical layers. A broadband cabling system supports transmission of multiple services over a single cable by dividing the bandwidth into separate frequencies, with each frequency assigned to a different service. This technique is used in cable TV transmission systems to transmit multiple channels over a single cable. Each channel uses a different frequency range. This capability can allow 10Broad36 share a single cable with other services such as video.
Q22:What is Twinaxial cables? Answer:
Twinaxial is a type of communication cable consisting of two center conductors surrounded by an insulating dielectric which in turn is surrounded by a tubular outer conductor (usually a braid, foil or both). The entire assembly is then covered with an insulating jacket. Twinaxial is constructed much like coaxial cable, except it has two center conductors instead of one. However, it is similar to twisted pair cabling in that it uses differential,or"balanced", transmission. 150-ohm twinaxial is specified as a "short haul" cable that can be used with the 1000Base-CX media system. Although twinaxial has better transmission characteristics than twisted pair media, it supports segment lengths of only 25 meters for 1000Base-CX due to the very high 1.25G baud signal transmission rate.
Q23:What is Fiber Optics Cable? Answer:
Fiber optics cable is a technology where electrical signals are converted into optical signals, transmitted through a thin glass fiber, and re-converted into electrical signals. It is used as transmission medium for the following Ethernet media systems: FOIRL, 10Base-FL, 10Base-FB, 10Base-FP,100Base-FX, 1000Base-LX, and 1000Base-SX.
Fiber optics cable is constructed of three concentric layers:The "core" is the central region of an optical fiber through which light is transmitted.The "cladding" is the material in the middle layer. It has a lower index of refraction than the core which serves to confine the light to the core. An outer "protective layer", or "buffer", serves to protect the core and cladding from damage.
We recommend a horizontally run, multimode fiber optics cable for indoor LANs.A multimode fiber optics cable has several hundred modes,individual parameters of light called "waveguides".A minimum of six (6) strands per cable is recommended, while twelve (12) strands are optimal. Cable can be PVC or riser type for non-plenum areas.Plenum areas require a plenum rated,Communications Plenum (CMP),type cable.Fiber optic connectors are single terminus (ST) or subscriber connector (SC) type connectors, either epoxy or crimp type. LIU boxes are used to allow a permanent fiber termination point. Fiber optics cable technology is the future of computer applications and telecommunications networks. Fiber optics cables high capacity supports video,data and interactive services of all kinds.
Benefits Fiber optics cable is an excellent choice for horizontal station runs to central hubs and backbones.
Fiber optics cable eliminates distance/distribution problems, which are typical of copper cable systems.
Fiber optics cable are also immune to electromagnetic intrusions, crosstalk,radio frequency interference, impedance mismatches, ground loops and transmission frequency variances.
Fiber optics cable remains quite stable and presents a secure means for priority transmissions,which normally create problems for copper cable.
Fiber optics cable have exceptional ability to accommodate transmission bandwidths, when matched with the proper mode of operation.
Q24:What is Multi-Mode Fiber Cables? Answer:
Multi-mode fiber allows many "modes", or paths, of light to propagate through the fiber optic cable. The relatively large core of a multi-mode fiber allows good coupling from inexpensive LEDs light sources and the use of inexpensive couplers and connectors. Multi-mode fiber typically has a core diameter of 50 to 100 microns.
Two types of multi-mode fiber exist with a refractive index that may be "graded" or "stepped". With graded index fiber the index of be "graded" or "stepped". With graded index fiber the index of refraction of the core is lower toward the outside of the core and progressively increases toward the center of the core, thereby reducing modal dispersion of the signal. With stepped index fiber the core is of uniform refractive index with a sharp decrease in the index of refraction at the core-cladding interface. Stepped index multi-mode fibers generally have lower bandwidths than graded index multi-mode fibers.
The most popular fiber for networking is the 62.5/125 micron multi-mode fiber. These numbers mean that the core diameter is 62.5 microns and the cladding is 125 microns. Other common sizes are 50/125 and 100/140.
The primary advantage of multi-mode fiber over twisted pair cabling is that it supports longer segment lengths. Multi-mode fiber can support segment lengths as long as 2000 meters for 10 and 100 Mbps Ethernet, and 550 meters for 1 Gbps Ethernet.
The industry recommends fiber optic cable be considered for distances greater than 295 feet, when electromagnetic interference is a problem or when transmissions bit rates exceed 350 MHz.
Q25:What is Single-Mode Fiber? Answer:
Single-mode fiber has a core diameter in 10 micron to allow only single mode of light to propagate.This eliminates the main limitation to bandwidth and modal dispersion.However,the small core of a single-mode fiber makes coupling light into the fiber more difficult,and thus expensive lasers must be used as light sources. The main limitation to the bandwidth of a single-mode fiber is material (chromatic) dispersion.Laser sources must also be used to attain high bandwidth, because LEDs emit a large range of frequencies,and thus material dispersion becomes significant.
Single-mode fiber is capable of supporting much longer segment lengths than multi-mode fiber.Segment lengths of 5000 meters and beyond are supported at all Ethernet data rates through 1 Gbps.Single-mode fiber is significantly more expensive to deploy than multi-mode fiber because of the high laser equipment cost.
Q26:What is RJ-45 connector? Answer:
An "RJ-45" connector is used on Ethernet twisted pair links.An RJ-45 connector has 8-pins, and may also be referred to as an "8-pin Modular Connector". A male RJ-45 "plug" is usually mounted at the end of the UTP cable. A female RJ-45 jack is usually built into the Ethernet hub.
Q27:What is IBM Cabling System? Answer:
The original IBM Cabling System specification defined the 150 ohm STP cable Types 1, 2, 6, 8, & 9 for support of frequencies up to 16 MHz.It also defined the 100 ohm Type 3 UTP cable, and Type 5 & 5J fiber optic cables. Later, an enhanced IBM Cabling System defined STP-A cable Types 1A, 2A, 6A, & 9A for support of FDDI and frequencies up to 300 MHz. The "A" suffix denotes the enhanced IBM Cabling System. The original IBM Cabling System was defined in IBM publication GA27-3773. The enhanced, or STP-A, cabling is defined in the TIA/EIA 568-A standard.
Generically, the term "shielded twisted pair" can be used to refer to any twisted pair cabling in which the overall cables are screened with an outer shield. Individual pairs may also be shielded. However, the acronym "STP" most often refers to the 150 ohm shielded twisted pair cables defined by the IBM Cabling System specifications and used with Token-Ring networks. 150 ohm STP should not be confused with the 100 ohm shielded twisted pair used with Ethernet networks commonly known as "screened twisted pair" (ScTP) or "foil twisted pair" (FTP). Type 1 (1A) STP is the stiff black cable most commonly associated with the IBM Cabling System. It contains two "data grade" shielded twisted pairs. Type 2 (2A) STP is the same as Type 1 (1A) except that it also contains four "voice grade" twisted pairs. The two data grade pairs are intended for data networking such as Token-Ring, while the four voice grade pairs are intended for telephone connections. Type 2 (2A) STP allows a single cable to be routed to each office that supports both data and voice connections.Types 6 (6A) & 9 (9A) STP contain two shielded twisted pairs that are constructed of a smaller wire gage that makes them better suited for applications where a flexible cable is required. Type 6 (6A) is typically used for short patch cables. Type 9 (9A) is typically used to connect between a station adapter and a wall outlet. Type 8 cabling consists of two individually shielded flat parallel pairs.The wires pairs are flat instead of twisted which reduces the thickness of the cable. This makes Type 8 ideal for an office environment where the cabling has to be routed under carpet.
IBM Type 3 cabling is similar to the Category 3 "unshielded twisted pair" (UTP) cabling typically used with Ethernet 10Base-T. It has a 100 ohm impedance in contrast to the 150 ohm impedance of STP cabling. It usually includes four twisted pairs as opposed to STP cabling which has only two twisted pairs.
Q28:What is Patch cord bending radius? Answer:
Patch-cord bend radius as stated in TIA/EIA-568-A document section 10.6.3.2,shall not be less than four times the cable diameter for horizontal cable." This applies to termination on the back of the patch panel and outlet location where the horizontal cables terminate and bend-radius stability can occur due to securing the cables in place by tie wraps or other means, but at the front of the patch panel or work area location patch-cords may be in a state of flux from moves, adds, or changes and securing of patch.
cords become impartial in real life. While the standards do not address the bend radius of patch cords, neither do they advocate the kinking of patch cords, which can lead to signal degradation in copper and broken glass in fiber patch cords.
Q29:What is Plenum/Non-Plenum cable? Answer:
In the US market, there are two kinds of sheathing material for STP & UTP cables. One of them is Plenum and another is Non-Plenum. When the Plenum cables are on fire, it may release only a few smokes and poisonous gas. Therefore, the US organization required that the Plenum cables shall be used for all exthermic equipments and air-conditioners. Except this, the Non-Plenum cables can be considered in other places. PVC material is commonly used for Non-Plenum cables.
Q30:What is the installation distance? Answer:
Installations are limited to a total cable distance of 328 feet (100 meters) per node. Anything over the maximum distance of 328 feet begins to lose the signal. Installing a higher grade of cable and terminating hardware may allow the maximum distance to increase to 492 feet (150 meters) over the same working frequency.
Q31:What is 568B wiring configuration? Answer:
The 568B wiring configuration is the primary choice for many installations.The 568B wiring configuration is adopted for multimedia workstations, where digital telephone jacks are offered in one media outlet housing. With the use of 568B wiring configuration, wrong connection to the network equipment is highly minimized.
Q32:What is a Demarc? Answer:
Demarc stands for demarcation point. It is the transition point where outdoor cabling interfaces with the indoor cabling.
Q33:What is Cable Topology? Answer:
The cable topology describes the way that stations on the network are connected together.Each topology has its own advantages and disadvantages.Structured Wiring Systems use the star topology.There are three major cable topologies: Daisy Chain, Bus and Star.Computer networks generally use one topology, though ARCnet may use both bus and star topology.Office telephones (one extension per phone) use a star configuration,while home telephones (all on one extension) are often daisy chained.
Q34:What is Daisy Chain Topology? Answer:
With a daisy chain,each station is plugged into the device upstream and downstream from itself.Phonenet and Etherwave are two cabling systems that daisy chain devices together.
Advantages: These are very easy to connect all the devices together.They require a minimum of cable as compared to other cable configuration.It is easy to add more devices anywhere in the chain.
Disadvantages: A component failure or cable failure in midstream will disable the entire network. Also, if you want to add a device in the middle of the chain,the network will get down during the process.The cabling for these networks is generally put in open space and may therefore be more vulnerable to accidental disconnections and breaks.
Q35:What is bus Topology? Answer:
With a bus topology,all stations are attached to the same cable.The most popular networks using a bus topology are 10BASE2 and 10BASE5 Ethernet.Arcnet can also run on a bus topology.
Advantages: A bus requires less cable because you only need enough to chain the stations together.There is no central point of failure on a bus because there is no hub.
Disadvantages: However,a bus can be even more vulnerable to failure than a star because any problem impacts the entire network.A bus can make troubleshooting difficult for the same reason.
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