OV 3 - 1 Copyright © 2013 Logical Operations, Inc. All rights reserved. Network Media and Hardware ...

OV 3 - 1Copyright © 2013 Logical Operations, Inc. All rights reserved.

Network Media and Hardware

Bounded Network Media Unbounded Network Media Noise Control Network Connectivity Devices


Network Media

Bounded mediaBounded media

Unbounded mediaUnbounded media


Copper Media

A type of bounded media Uses copper conductors surrounded by insulated coating Conductors - solid wire or from braided strands of wire Shielding wrapped around conductors


Twisted Pair Cables

Primary wires are striped

Primary wires are striped

Multiple wires enclosed in a

sheath

Multiple wires enclosed in a

sheath

Primary and secondary wiresPrimary and secondary wires


Twisted Pair Cable Types

Cable Type Description

UTP

Characteristics of UTP are:Does not include shielding around its conductorsContains four pairs of stranded or solid conductorsInexpensive and reliableSupports transmission distances of up to 100 metersSupports data transfer rates of up to 1 Gbps

STP

Characteristics of STP are:Includes foil wrapper shielding around its conductors Contains four pairs of stranded or solid conductorsMore expensive than UTPSupports distances up to 100 metersSupports data transfer rates of 10 to 100 Mbps


Twisted Pair Cable Categories

Category Specification

1 Network Type: Voice transmission, not suitable for data networking Maximum speed: 1 Mbps

2 Network Type: Digital telephone and low-speed data networks Maximum speed: 4 Mbps

3

Network Type: Ethernet Maximum speed: 10 Mbps CAT 3 is currently used for telephone wiring

4

Network Type: IBM Token Ring Maximum speed: 16 Mbps CAT 4 may also be used for 10 Mbps Ethernet


Twisted Pair Cable Categories (Cont.)

Category Specification

5 Network Type: Fast Ethernet Maximum speed: CAT 5 supports a signaling rate of 100 Mbps

5e Network Type: Gigabit Ethernet Maximum speed: CAT 5e supports a signaling rate of 350 Mbps

6

Network Type: Gigabit Ethernet Maximum speed: 1 Gbps CAT 6 supports a signaling rate of 250 MHz

7

Network Type: Gigabit Ethernet Maximum speed: 1 Gbps+ CAT 7 supports a signaling rate of 1 Ghz


Coaxial Cables

Braided shieldingBraided shielding

Single copper conductor

Single copper conductor

Non-conductiveinsulated coating Non-conductive

insulated coating


Coaxial Cable Types

Cable Type Characteristic

R58/U 5 mm (0.25 inch) coax cable with solid core and 50 ohms impedance Used for Ethernet networking

RG58A/U

5 mm (0.25 inch) coax cable with stranded core and 50 ohms impedance

Used for Ethernet networking

RG8 10 mm (0.5 inch) coax cable with solid core and 50 ohms impedance Used for Ethernet networking

RG9

10 mm (0.5 inch) coax cable with stranded core and 51 ohms impedance

Used for cable television transmission and cable modems

RG62 5 mm (0.25 inch) coax cable with solid core and 93 ohms impedance Used for ARCNET networking

RG59 6 mm (0.24 inch) coax cable with 75 ohms impedance Used for low-power video connections such as digital receivers

RG6

Coax cable with 75 ohms impedance Most often used in routing cable television signals Preferred over RG59


Coaxial Connector Types

Connector Type Characteristic

F

Coax connector type used with 75-ohm cable to connect cable TV and FM antenna cables

Comes in a secure screw-on form or as a non-threaded slip-on connector

BNC

Cable connector used to terminate a coaxial cable Used with the RG58/U cable Has a center pin connected to the center cable conductor and a

metal tube connected to the shield of cable Rotating ring outside metal tube locks cable to connector. The types of BNC connectors include:

T-connector Barrel connector Terminator


Network Media Performance Factors

Factor Description

Noise

Electromagnetic interference disrupting the signal Signal to noise ratio decreases as transmitting distance

increases

Attentuation

Progressive degradation of a signal as it travels across a network medium

Caused by increase of noise or decrease in signal strength Susceptibility to noise and attenuation depends on media types

used Occurs when cable length exceeds length up to which signals

can travel without distortion

Impedance Opposition to flow of electricity in an AC circuit Measured in ohms (Ω)


Media Converters

Enables networks running on different media to interconnect and exchange signals

To install a media converter: Connect terminated ends of the two media to bridge to converter May need to provide electrical power to the converter


Media Converters (Cont.)

Converter Type Description

Multimode fiber to Ethernet

Used to extend an Ethernet network connection over a multimode fiber backbone

Similar in appearance to BNC connectors

Fiber to Coaxial Used to convert signals on fiber to coaxial cable

Singlemode to multimode fiber

Used to transmit multimode fiber signals over singlemode fiber devices and links

Supports conversion between multimode segments on a network that spans a wider coverage area


Structured Cabling

Is based on 568 Commercial Building Telecommunication Cabling standard developed by Telecommunications Industry Association (TIA) and Electronic Industries Association (EIA) The cabling standard defines regulations on designing, building, and managing a cabling

system utilizing structured cabling according to specified performance characteristics to create a system of unified communications

Is based on hierarchical design that divides cabling into six subsystems


Structured Cabling (Cont.)

Subsystem Description

Entrance facilities

Contains telecommunication service entrance to the building, campus-wide backbone connections, and interconnection to local exchange carrier's telecommunication facilities

Network demarcation point one foot away from where the carrier's facilities enter the building

Carrier designates a different measurement, depending on the needs of facility

Backbone wiring

Provides connections between equipment rooms and telecommunication closets

Runs through floors of building via risers or across campus Allowed distance measurements depend on cable type and

facilities that it connects to

Equipment room

Provides main cross-connection point for an entire facility Provides termination point for backbone wiring connected to

telecommunication closets


Structured Cabling (Cont.)

Subsystem Description

Telecommunications closet

Houses connection equipment for cross-connection to an equipment room with workstations

Contains horizontal wiring connections, and entrance facility connections Can be as many telecommunications closets as needed in an office building

Horizontal wiring

Runs from each workstation outlet to telecommunication closet Maximum allowed distance from outlet to closet is 295 feet Additional 20 feet allowed if patch cables are used, but combined length cannot

be more than 33 feet Specifications include:

Four-pair 100 ohms UTP cable Two-fiber 62.5/125 mm fiber-optic cable Multimode 50/125 mm multimode fiber-optic cable

Work area Consists of wallboxes and faceplates, connectors, and wiring Required that a data and voice outlet be available at each wallbox and faceplate


Premise Wiring

A hierarchical cable system architecture in which a Main Cross-Connect (MCC) is connected via a star topology across backbone cabling to Intermediate Cross-Connects (ICC) and Horizontal Cross-Connects (HCC)

Cross-connects of premise wiring are referred by nonstandard terms as distribution frames, Main Distribution Frames (MDFs), Intermediate Distribution Frames (IDFs), and wiring closets


Premise Wiring (Cont.)

Rack in a wiring closetRack in a wiring closet

Drop cable Drop cable

Patch cablesPatch cables

Patch panelsPatch panels


Plenum and PVC Cables

Plenum cable: Is a network cable jacketed tightly around conductors so that fire cannot travel

within the cable Cable jacket does not emanate poisonous gases when burned Fire codes require installation of this special grade cabling in the plenum Can run through the plenum and firebreak walls

PVC cable: Refered to as non-plenum cable Is inexpensive and flexible Emanate poisonous gases when burned PVC jacketing is not formed tightly to the conductors Allow fire to travel through it


Plenum and PVC Cables (Cont.)


Fiber Optic Cables

Strengthening fibers

Strengthening fibers

Reflective cladding and bufferReflective cladding and bufferOuter jacketOuter jacket

Glass or plastic strands

Glass or plastic strands

CoreCore


Fiber Optic Cable Modes

There are two modes of fiber optic cables: single mode and multimode Both modes of cables have outer diameter of 125 microns Multimode

Light travels through its core in multiple rays or modes Core of 50 or 62.5 microns

Singlemode features Diameter of 9 microns Light travels unidirectionally within the cable Used with laser for telephony and cable TV transmission


Fiber Optic Cable Modes (Cont.)

Fiber Optic Cable Mode

Description

Singlemode fiber

Carries an optical signal through a small core, allowing only a single beam of light to pass

A laser, operating in the infrared portion of the spectrum, is modulated in intensity to transmit the signal through the fiber

Provides bandwidth of up to 30 MHz

Step-index multimode fiber

Contains a core surrounded by cladding When light from the core enters the cladding, a “step down”

occurs due to difference in refractive indices Uses total internal reflection to trap light

Graded index multimode fiber

Possesses variations in the core glass Provides up to 2 GHz of bandwidth


Fiber Connectors

Fiber Optic Connector

Description

Straight Tip (ST)

Similar in appearance to BNC connectors Used to connect multimode fibers Has a straight, ceramic center pin and bayonet lug lockdown Often used in network patch panels A popular type of fiber connector

Subscriber Connector or Standard Connector (SC)

Box-shaped connectors that snap into a receptacle Often used in a duplex configuration Used with a singlemode fiber

Face Contact (FC)

Use a heavy duty ferrule in the center Ferrule-tubular structure made of ceramic or metal that

supports the fiber Are more popular in industrial settings

FDDI

Used for multimode fiber optic cable Are a push/pull-type, two-channel snap-fit connectors Also called Media Interface Connector (MIC)


Fiber Connectors (Cont.)

Fiber Optic Connector

Description

Biconic

Screw-on type connector with a tapered sleeve On inserting the connector into the receptacle, tapered end of

connector locks fiber optic cable into proper position One of the earliest connector types

Local Connector (LC)

Used for both singlemode and multimode fiber Is half the size of the SC or ST connectors Use an RJ-45-type latching Used to transition installations from twisted pair copper

cabling to fiber

Sub Multi Assembly or Sub Miniature Type A (SMA)

Similar to ST connectors and use a threaded ferrule on the outside

Used where water or other environmental factors necessitate a waterproof connection

Mechanical Transfer Registered Jack (MT-RJ)

Also called a Fiber Jack connector Snap-to-lock connector used with multimode fiber Similar in size to an RJ-45 connector


Cable Properties

Cable Properties

Twisted pair

Transmission speed:CAT 3 – UTP at 10 MbpsCAT 5 – Up to 100 MbpsCAT 6 – Up to 155 Mbps

Distance: 1800 ft

Duplex: Supports full-duplex transmission

Noise-immunity (security, EMI): 30 MHz

Frequency: Up to 600 MHz

Coaxial

Transmission speed: 10 Mbps

Distance: Star topology – 2000 ft

Bus topology – 1000 ft

Duplex: Supports both half-duplex and full-duplex transmission

Noise-immunity (security, EMI): High

Frequency: 1 GHz to 10 GHz


Cable Properties (Cont.)

Cable Properties

Fiber optic

Transmission speed: 40,000 Mbps

Distance: Multimode fiber is typically used for shorter runs of up to about 500 meters, and singlemode for longer runs. The ultra high-quality of some fiber cables allows runs of 62 miles or more between repeaters, which are rarely used now.

Duplex: Supports full-duplex transmission as it consists of two fibers that can be used for simultaneous, bi-directional data transfer.

Noise-immunity (security, EMI): High

Frequency: Normally the frequency is very high and its range depends on the bandwidth and the device that you use.


Other Cable Media Types

Cable Type Description

Serial cable

Type of bounded network media that transfers information between two devices using serial transmission

Information sent one bit at a time in a specific sequence Uses an RS-232 connector In networking, used to connect routers Null modem serial cables used by networking professionals

IEEE 1394 (FireWire™)

It is commonly known as FireWire Used to connect up to 63 devices to form a small local network Cables use a shielded cable similar to STP with either four or six

conductors Connections to devices made with either a six- or four-pin

connector

USB

A personal computer connection to connect multiple peripherals to a single port

Support two-way communications


Wireless Communication

Signals are transmitted over a distance without the use of a physical medium

Signals are transmitted over a distance without the use of a physical medium


Radio Networking

Signals are sent via RF waves

Signals are sent via RF waves


Broadcast Radio

Non-directional single frequency transmissionNon-directional single

frequency transmission


Spread Spectrum

Signal is sent over more than one frequency

Signal is sent over more than one frequency


Types of Spread Spectrum

Spread Spectrum Type

Description

Frequency Hopping Spread Spectrum (FHSS)

Sends signals on one channel at a time Channel changes at fixed predetermined intervals Both sender and receiver use same selection and order of

frequencies Does not significantly reduce noise or improve the signal-to-noise

ratio

Direct Sequence Spread Spectrum (DSSS)

Uses multiple channels simultaneously to send data Error Detection And Correction (EDAC) techniques used to reduce

data transmission errors Single data signal converted into multiple data signals called chips Set of chips sent across a wide band of adjacent channels Upon receiving data, receiver combines and converts signals back

into original Signal can be reconstructed only if some channels are received

clearly


Infrared Transmission

Receiver

Needs an unobstructed view of the sender to successfully

receive the signal

Needs an unobstructed view of the sender to successfully

receive the signal

Signals are sent as pulses infrared lightSignals are sent as pulses infrared light


Bluetooth

Maximum 30 feet of signal coverage


Microwave Transmission

Sender transmits electromagnetic signals

Sender transmits electromagnetic signals

Receiver has an unobstructed viewReceiver has an

unobstructed view


Wireless Access Points

WAP

Device that provides a connection between wireless devices

Device that provides a connection between wireless devices


Electrical Noise

Noise in the network medium

Noise in the network medium


Sources of Electrical Noise

Noise Source Property

Ambient noise

Can come from many sources, including solar disturbances or radio broadcasting towers

Naturally occurring forms of noise Affect both bounded and unbounded media

Power wires

High-tension power lines can create electrical noise Network cables parallel to electric wires more susceptible to

electrical noise than those that run perpendicular

Electric motors

Used in elevators, refrigerators, water fountains, and HVAC equipment

Create noise while running Require huge amount of electricity to start up, causing noise Bursts create temporary outages

Electrical heat-generating devices

Use a lot of electricity Cause significant amount of electrical noise while running

Fluorescent, neon, and High-Intensity Discharge (HID) lights

Produce large amount of electrical noise Creates enough noise during operation to interfere with

networking signals


Grounding

Rack frame connects to the ground

Rack frame connects to the ground

Groundpoint

Groundpoint

ConductorConductor


Shielding

Drain

Noise

ShieldShield


Differential Signaling

Signal with positive noise

Signal with negative noise

Signal after removing the noise


Noise Control with Twisted Pair

Closely wound; less noise in the signalClosely wound; less noise in the signal

Loosely wound; more noise in the signalLoosely wound; more noise in the signal


Termination

Terminator Terminator

Prevents signal reflection

Prevents signal reflection


Noise Reduction Considerations

Noise Reduction Consideration

Description

Separate data and electrical cables

Do not run data and electricity cables in the same trays, raceways, and conduits

Avoid running network cables parallel to each other when you can

Fluorescent lights

Keep network cables at least 20 inches from fluorescent lights as it can cause electromagnetic interference

If you must run data cables across or near these lights, do so in such a way that exposes the smallest length of cable to the light

Power ground Make sure to ground all equipment and electrical circuits according

to the manufacturer's instructions and local building codes

Connector installation

Follow standards, specifications, and manufacturer's directions when installing network cables

Do not unwind conductor pairs any more than required or allowed Make sure connectors are firmly attached and connected to power

outlets


NICs

Network Interface Card (NIC): A device that serves as an interface between the computer and the network Also called as network adapter or network card Can be built into the motherboard of the computer or can be connected using a

USB, PC card, CompactFlash or FireWire port


Transceivers

Transceiver chipTransceiver chip


Switches

Switch

Connects pairs of ports

Connects pairs of ports


Virtual Switches

Software-based switch that provides functionality similar to physical switches Used to connect systems on a virtual network Contains a core forwarding unit that forwards packets to the correct virtual

systems Check MAC address of each packet like a physical switch, and forwards the

packet to one or more virtual ports for transmission Contains a VLAN tagging unit, a packet filtering unit, and a security unit Traffic cannot directly flow from one virtual switch to another in the same host

network Two virtual switches or VLANs cannot communicate directly


Routers

Router

Divides network based on network

addresses

Divides network based on network

addresses


Gateways

Gateway

LAN interface

LAN interface

WAN interface

WAN interface


Virtual Servers

Remote software that can run its own operating systems or applications Composed of only software components and behaves similar to a real

computer Has characteristics similar to a physical computer and contains its own virtual

software-based CPU, RAM, hard drive, and NIC Operating system will behave in the same manner as in physical servers No major functionality changes in the way applications or computer networks

behave Offer distinct advantages over physical servers


Virtual PBX

Private communications service provider that provides low cost PBX service Used to manage phone-based tasks such as voicemail, faxing, conference

calling, and call routing Physical PBX system – involves very high cost investment with expensive

hardware Virtual PBXs – allow smaller businesses to utilize PBX services without the

need for physical PBX Utilizes traditional Public Switched Telephone Network (PSTN) with Voice over

IP (VoIP) technology


NaaS

Organizations can purchase networking infrastructure, and when they do not need it, they can lease the network as a service to a client.

NaaS

PaaS IaaS


Legacy Network Connectivity Devices

Network Device

Description

Repeater

A device that regenerates a signal to improve signal strength over transmission distances

Using repeaters, you can exceed the normal limitations on segment lengths imposed by various networking technologies

Used frequently with coax media, such as cable TV Most networks today use twisted pair cabling Wireless network repeaters and bridges are frequently used to extend the range of a

WAP

Hub

A networking device to connect the nodes in a physical star topology network into a logical bus topology

Contains multiple ports to which the devices can be connected Two common types of hubs: passive and active Passive hub – receives data transmitted from a device to one port and broadcasts it

out to devices connected on all other ports Active hub – performs same receive then broadcast action as a passive hub, and

also regenerates or boosts the signal much like a repeater

Bridge

A network device that divides a logical bus network into segments Examine the MAC address of each packet Helps reduces traffic between segments and improves overall network performance


Reflective Questions

1. Which will you use more frequently in your networks: bounded or unbounded media?

2. Of the various networking devices, which offers you the best mix of features and functionality?

OV 3 - 1 Copyright © 2013 Logical Operations, Inc. All rights reserved. Network Media and Hardware ...

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Transcript of OV 3 - 1 Copyright © 2013 Logical Operations, Inc. All rights reserved. Network Media and Hardware ...