Types of Cabling

Types of Cabling

• Learning Objectives:
• - Distinguish between shielded and shielded twisted-pair cabling
• - Describe how fiber cabling works
• - Distinguish between RG-6 and RRG-59 coaxial cabling
• - Use the most appropriate Cabling in a given scenario

Types of Cabling

• - There are many different types of cable used in an IT environment.
• - Different Cabling Types have different characteristics and are designed for different uses.

Different Types of Cabling

• - Unshielded Twisted Pair or UTP Cable
• - Shielded Twisted Pair or STP Cable
• - Plenum/PVC Cable
• - Fiber Optic or Fiber Cable
• - Coaxial or Coax Cable

Twisted Pair Cabling

• - Twisted Pair Cabling is used for Ethernet Networks and Telecommunications
• - TPC can either be shielded or unshielded
• - TPC Cable consists of intertwined pairs of insulated copper wire, each in a different colour
• - The Individual wires are encased within a plastic sheath and sometimes a metal shield and then covered with a second plastic sheath
• - The number of pairs within the cables sheath is one of the factors that determines what the cable can be used for

Unshielded or Shielded TPC

• UTP
• - UTP is the cheapest and most common cable used in computer networking.
• - It's made up of multiple wire pairs and its small size makes it easier to install.
• - UTP lacks extra shielding and isn't very resistant to electromagnetic interference or EMI
• - UTP is one of the fastest copper based cables in use.
• - Data throughput speed pf 10 Mbps to 10Gbps and a maximum length of 100 metres.
• STP
• - Each twisted wire pair in the cable is wrapped separately in a shield of metallic foil
• - This guards against EMI and radio frequency interference or RFI
• - STP is more expensive than UTP.
• - Effectiveness varies according to amount of environmental noise, and the symetry, consistency, material and thickness of the cable shielding.
• - If it is not grounded correctly,

TIA/EIA 568

• The TIA/EIA 568 standard divides twisted-pair cabling into several categories, Including:
• - Category 3: A UTP Cable compromising four wire pairs and can transfer data at 10Mbps. It is typically used in 10Mbps Ethernet or 4 Mbps Token Ring Networks and for telephone wiring. Most CAT3 have been replaced by CAT5 which allows hire throughput.
• - Category 4: A UTP Cable compromising four wire pairs and can transfer data at 16Mbps. Category 4 is typically used for 16Mbps Token Ring or 10Mbps Ethernet Networks. CAT4 offers more protection against crosstalk and attenuation.
• - Category 5: A UTP Cable compromising four wire pairs and can transfer data at 100Mbps, although specifications for 1000Mbps CAT5 exists. The wire pairs in a CAT5 have a twist ratio of atleast 3 twists per inch.
• - Category 5e: This is an enhanced category 5 and is designed to support transfer speeds of up to 1 gigabit per second. The wires are made from high quality copper, have a high twist ratio and have improved crosstalk and attenuation properties.
• - Category 6: A UTP Cable compromising four wire pairs, each wrapped in foil insulation. The central bundle has an additional foil layer and fire resistant plastic sheath covers the second foil layer. This ensure resistance to crosstalk.
• - Category 6e: This is an enhanced CAT6 cable which supports data throughput at multiple gigabits per second. It prevents cross talk and attenuation and can be used over greater distances.

Plenum Cable

• - Plenum Cable is a specially rated that is used in the space of a building where the air conditioning is located, either under floors or above ceilings.
• - This space is known as Plenum Space
• - Unlike standard cables Plenum Cabling is covered in a fire resistant cladding. In the event of a fire the cladding does not burn easily, or emit the toxic gas and smoke that regular cladding does.

Fibre Optic Cable

• - Fibre Optic Cable is composed of one or more flexible, transparent plastic or glass fibres.
• - Data is transmitted through the cable via a laser or LED - these send pulses of light through the cables central fibres.
• - The fibre used to transform data in the form of light is located in the centre of the cable cladding. The cables inner cladding is denser than the outer protective cladding.
• - Light reflects of the cladding internally, this helps prevent data loss.
• - Fiber Cabling is currently used for high speed data transfer and to create connections across long distances without requiring repeaters.
• - Fiber Cable can run for longer distances and at higher speeds than copper cables.
• - Fiber Cable is useful because:
• - isn't affected by EMI & RFI
• - has very high throughput
• - meets industry standards for high speed networking
• - maintains high security.

Fiber Cabling Disadvantages

• - Fiber Cabling is significantly more expensive than copper cabling.
• - Fiber Cabling is also difficult to install and troubleshoot.
• - Repairing Fiber is also very difficult
• - The loss factor of the fiber cable refers to the amount of degredation a light signal travelling through the cable receives before it reaches its destination.
• - One type of loss that can occur is connector loss. Any section of fibre that has had a connector fitted can be expected to suffer a slight signal loss.
• - Another potential loss factor is attenuation. This refers to the decrease in signal strength as it moves through the cable. The longer the fiber is, the greater the chance of attenuation.

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Microbending and Macrobending

• Microbending
• Microbending occurs when the light source is distorted by a deformation in the fiber.
• This leads to attenuation.
• Macrobending
• Macrobending occurs when light leaks through the cable.
• This happens when the cable is bent too much.
• You can install optical amplifiers to minimize the affects of microbending over long distances.
• Optical amplifiers amplify light signals directly without having to convert to an electrical signal first.

Types of Fiber Cable

• Single-Mode Fiber
• - SMF Cable has a core less than 10 microns wide.
• Signal dispersion is low due to the narrowness of the core.
• - SMF can support high bandwidths over long distances with no repeaters and can be used to connect a carrier's facilities.
• - This is expensive and not typically used for data networks.
• - SMF uses a laser to transmit light in 1310 or 1550 nanometer wavelengths.
• - Because of the high signal strength produced by a laser SMF can support data transmission rates at 100gbps over a distance of 6 miles without the use of repeaters
• Multimode Fiber
• - MMF has a core with a width of between 50 and 100 microns, typically 62.5 microns.
• - A laser of LED generates light that travels in pulses at different angles along the fibers in the cables.
• - MMF is commonly used for cabling that connects the router to a server or a switch on the backbone on a network
• - MMF uses an LED to transmit light in 850 or 1300 nanometer wavelengths. You cant see this light with the naked eye because it fulls within the infrared spectrum.
• - Data transfer speeds vary from 100mbps to 1gbps depending on distance,

Enhancing Signal

• Technologies that enhance the performance of fiber cable include:
• - WDM: Wave Division Multiplexing
• - DWDM: Dense Wave Division Multiplexing
• By using different wavelengths, WDM enables a fiber cable to carry more two signals at a time.
• DWDM enables a fiber cable to carry an even greater number of signals. With different wave lengths spaced close together, a single can have 200 or more signals multiplexed into a light stream.
• One of the advantages of DWDM is the flexibility it provides to the traffic and protocols carried through the fiber by enabling different signal types to be sent through one fiber.
• DWDM is also scalable. It makes it quick and easy for carriers to add new connections because this doesn't require the installation of new fiber lines.
• For example, an ethernet connection, an IP connection and an ATM could all use different wave lengths on the same fiber cable.

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Multiplex Transmission Standards

• SONET
• Synchronous Optical Network, or SONET, is most commonly used in North America. It is defined by the American National Standards Institute, or ANSI and the Exchange Carriers Standards Association or ECSA.
• SDH
• Synchronous Digital Hierarchy, or SDH, standard is used in most parts of the world excluding North America.

SONET Standard

• With SONET, data transmission includes an overhead - which is similar to a header - and a payload. The overhead is interleaved with the payload during transmission.
• Types of Overhead Include:
• - Section Overhead: Links between devices such as repeaters use section overheads or SOH.
• - Line Overhead: Single or Multiple Sections that connect network devices such as hubs use line overhead or LOH.
• - Path Overhead: Devices used to assemble and disassemble frames, such as carrier switches or the fiber interfaces of routers use path overhead or POH.

Coaxial Cabling

• Coaxial Cabling has a single conductor in its center, rather than multiple intertwined connectors.
• The conductor is protected by one or more shields, and a layer of insulating material insulates the conductor from the cable shield.
• The shielding makes coaxial cabling highly resistant to EMI.
• Coaxial cables are typically used to support communication requiring high bandwidth, for example on Computer Networks, Private Video Networks and Community Attenae Television.
• Coaxial Cables have a particular impedence rating that makes them only suited to particular systems. Incompatible coaxial cabling can cause significant problems.
• Common types of Coaxial Cabling include: RG-59; RG-6; RG-8; RG-58;

RG-59 Coaxial Cable

• Insulated with copper foil sheet.
• Commonly used in very high frequency or ultra high frequency reciever applications such as those in low power video or bulk radio frequency. it has an impedence of 70 - 75 ohms,
• rg-59 cable suffers significantly high-frequency loss rates, and so it isn't suitable for use over long distances.
• In such instances it is better to use rg6, rg11, or even UTP or Fiber cabling.
• RG59 is often used with consumer electronics such as cables or satelitte receivers.
• rg59 is also used to synchronize the timing between two pieces of professional digital audio equipment , such as ADAT Optical devices.
• Not as efficient at loss protection as other coaxial cables, rg59 costs less and is adequate for use over short distances.

RG-6

• RG-6 coaxial cable includes a range of cable designs with different characteristics in terms of:
• -shielding
• - composition of conductors
• - Type of insulating material used
• For general usage, RG-6 commonly refers to 75 Ohm Impedence coaxial cable with an 18 American Wire Gauge or, AWG, center conductor and aluminium foil for insulation.
• RG-6 is used in various commercial and residential applications; including:
• - Antenna and sattelite television.
• - Cable Television
• - Professional Video Applications
• You should perform a sweep test with an oscilloscope to check for attenuation if you plan to use rg-6 cable for multiple applications.