Networking

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Requirements for Communication (Computer)

Senders and Receivers There must a be a sender and a receiver with something to share via a message to facilitate communication

Senders and Receivers There must a be a sender and a receiver with something to share via a message to facilitate communication

Communication Medium A medium must exist between the sender and receiver over which the message travels (e.g., a cable)

Communication Medium A medium must exist between the sender and receiver over which the message travels (e.g., a cable)

ProtocolsProcedures, rules, or standards must be followed by computers when sending or receiving data

ProtocolsProcedures, rules, or standards must be followed by computers when sending or receiving data

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Computer Networks

Centralized Computing (1970s)The centralized computing model utilizes a central computer (mainframe) connected to terminals with all processing being done on the central computer

Centralized Computing (1970s)The centralized computing model utilizes a central computer (mainframe) connected to terminals with all processing being done on the central computer

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Computer Networks

Distributed Computing (1980s)The use of small computers networked together allowing users to perform a subset of tasks that in aggregate are equal to that of a centralized computer while also being able to share information between those computers

Distributed Computing (1980s)The use of small computers networked together allowing users to perform a subset of tasks that in aggregate are equal to that of a centralized computer while also being able to share information between those computers

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Computer Networks

Collaborative Computing (1990s)A synergistic form of distributed computing in which two or more networked computers are used to accomplish a common processing task where they are not only sharing data but also sharing processing responsibilities

Collaborative Computing (1990s)A synergistic form of distributed computing in which two or more networked computers are used to accomplish a common processing task where they are not only sharing data but also sharing processing responsibilities

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Types of Networks

NetworksMost networks utilize a combination of computing models that have evolved over time and are connected by one or more of the following network types:

• Local Area Network (LAN)• Wide Area Network (WAN)• Global Networks• Enterprise Network• Value-added Network (VAN)• Metropolitan Network (MAN)• Personal Area Network (PAN)

NetworksMost networks utilize a combination of computing models that have evolved over time and are connected by one or more of the following network types:

• Local Area Network (LAN)• Wide Area Network (WAN)• Global Networks• Enterprise Network• Value-added Network (VAN)• Metropolitan Network (MAN)• Personal Area Network (PAN)

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Network Types – Local Area Network

Local Area NetworkA computer network that spans a relatively small area allowing all computer users to connect with each other to share information and peripheral devices (e.g., printers)

Local Area NetworkA computer network that spans a relatively small area allowing all computer users to connect with each other to share information and peripheral devices (e.g., printers)

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Types of Networks – Wide Area Networks (WAN)

Wide Area Networks (WANs)A computer network that spans a relatively large area and is typically used to connect two or more LANs using different kinds of hardware and transmission media to cover large distances efficiently

Wide Area Networks (WANs)A computer network that spans a relatively large area and is typically used to connect two or more LANs using different kinds of hardware and transmission media to cover large distances efficiently

GlobalA WAN that spans multiple countries and may include the networks of several organizations (e.g. the Internet)

GlobalA WAN that spans multiple countries and may include the networks of several organizations (e.g. the Internet)

Value-added Network (VAN)A medium-speed, third-party-managed network that is economical as it is shared by multiple customer organizations that lease lines rather than investing in dedicated network equipment

Value-added Network (VAN)A medium-speed, third-party-managed network that is economical as it is shared by multiple customer organizations that lease lines rather than investing in dedicated network equipment

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Types of Networks – Wide Area Networks (WAN)

Enterprise Network & MAN

EnterpriseA WAN that is the result of connecting the disparate networks of a single organization

EnterpriseA WAN that is the result of connecting the disparate networks of a single organization

Metropolitan Area (MAN) A WAN network of limited geographic scope, typically in a city-wide area that combines both LAN and high-speed fiber-optic technologies

Metropolitan Area (MAN) A WAN network of limited geographic scope, typically in a city-wide area that combines both LAN and high-speed fiber-optic technologies

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Types of Networks – Personal Area Network (PAN)

Personal Area NetworkAn emerging technology that uses wireless communication to exchange data between commuting devices using short-range radio communication (Bluetooth), typically within an area of ten meters

BluetoothIs the enabling technology of the Personal Area Network and is a specification for personal networking of desktop computers, mobile phones, pagers, portable stereos, and other handheld devices developed by its founders Ericsson, IBM, Intel, Nokia, and Toshiba

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Networking Fundamentals – Servers and Clients

ServerAny computer on a network that makes access to files, printing, communication, and other services available to users on the network

ServerAny computer on a network that makes access to files, printing, communication, and other services available to users on the network

ClientAny computer, such as a user’s workstation or a PC on the network, or software application such as word processing program that uses services provided by the server. A client only requests service and usually has only one user

ClientAny computer, such as a user’s workstation or a PC on the network, or software application such as word processing program that uses services provided by the server. A client only requests service and usually has only one user

NetworkA network consists of three separate components: servers, clients and peers

NetworkA network consists of three separate components: servers, clients and peers

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Networking Fundamentals – Peers

PeerA computer that may both request and provide services PeerA computer that may both request and provide services

Peer-to-Peer Networks (P2P)Enables any computer or device on the network to provide or request services with all peers having equivalent capabilities and responsibilities (e.g., Napster)

Peer-to-Peer Networks (P2P)Enables any computer or device on the network to provide or request services with all peers having equivalent capabilities and responsibilities (e.g., Napster)

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Networking Fundamentals - Network Services

Network ServicesThe capabilities that networked computers share through the multiple combinations of hardware and software

Network ServicesThe capabilities that networked computers share through the multiple combinations of hardware and software

File Services (a)The networked computers store, retrieve, and move data files in an efficient manner.

File Services (a)The networked computers store, retrieve, and move data files in an efficient manner.

Print Services (b)The capabilities used to control and manage user’s access to network printers, plotters, fax equipment, etc.

Print Services (b)The capabilities used to control and manage user’s access to network printers, plotters, fax equipment, etc.

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Network Operating System (NOS)Is software that controls the network enabling computers to communicate by enabling network services

Network Operating System (NOS)Is software that controls the network enabling computers to communicate by enabling network services

Message Services (c)The capabilities that include storing, accessing, and delivering of text, binary, graphic, digitized video and audio data

Message Services (c)The capabilities that include storing, accessing, and delivering of text, binary, graphic, digitized video and audio data

Application Services (d)The capabilities that run software for network clients and enable computers to share processing power

Application Services (d)The capabilities that run software for network clients and enable computers to share processing power

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Networking Fundamentals – Transmission Media

Transmission MediaThe physical pathway to send data and information between two or more entities on the network. Characteristics of the media include the following:

Transmission MediaThe physical pathway to send data and information between two or more entities on the network. Characteristics of the media include the following:

BandwidthIs the transmission capacity of a communications channel or computer, measured in megabits per second (Mbps) (amount of binary data transmitted per second)

BandwidthIs the transmission capacity of a communications channel or computer, measured in megabits per second (Mbps) (amount of binary data transmitted per second)

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Networking Fundamentals – Transmission Media

AttenuationThis results when the power of an electrical signal weakens as it is sent over increasing distance

AttenuationThis results when the power of an electrical signal weakens as it is sent over increasing distance

Electro Magnetic Interference (EMI)Interference commonly caused by fluorescent lights, weather, or other electronic signals that affects the distance a signal can travel (increased attenuation)

Electro Magnetic Interference (EMI)Interference commonly caused by fluorescent lights, weather, or other electronic signals that affects the distance a signal can travel (increased attenuation)

EavesdroppingThe undetected capturing of network informationEavesdroppingThe undetected capturing of network information

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Networking Fundamentals – Media (Cable)

Twisted PairTwo or more pairs of insulated copper wires twisted together and may be shielded (STP) or unshielded (UTP). It is the lowest capacity of the cable options

Twisted PairTwo or more pairs of insulated copper wires twisted together and may be shielded (STP) or unshielded (UTP). It is the lowest capacity of the cable options

CoaxialContains a solid inner copper conductor surrounded by insulation and outer braided copper or foil shield. It comes in UTP and STP and is higher capacity than twisted pair

CoaxialContains a solid inner copper conductor surrounded by insulation and outer braided copper or foil shield. It comes in UTP and STP and is higher capacity than twisted pair

Fiber-OpticMade of light-conducting glass or plastic core, surrounded by more glass, called cladding, and a tough outer sheath. It is high capacity and used in high speed backbones

Fiber-OpticMade of light-conducting glass or plastic core, surrounded by more glass, called cladding, and a tough outer sheath. It is high capacity and used in high speed backbones

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Networking Fundamentals – Media (Cable)

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Networking Fundamentals – Media (Wireless)

WirelessA communication mechanism that has no physical transmission media, hence the name wireless, that works by transmitting electromagnetic signals through the air. Types of wireless media include:

• Infrared line of sight • High-frequency radio• Microwave methods

WirelessA communication mechanism that has no physical transmission media, hence the name wireless, that works by transmitting electromagnetic signals through the air. Types of wireless media include:

• Infrared line of sight • High-frequency radio• Microwave methods

Infrared Line of SightUses high-frequency light waves to transmit data on an unobstructed path between nodes – computers or some other device such as a printer – on a network up to 24.4 meters (i.e. most electronics remotes use this infrared light) and are susceptible to attenuation, EMI, eavesdropping, high-intensity light, and smoke

Infrared Line of SightUses high-frequency light waves to transmit data on an unobstructed path between nodes – computers or some other device such as a printer – on a network up to 24.4 meters (i.e. most electronics remotes use this infrared light) and are susceptible to attenuation, EMI, eavesdropping, high-intensity light, and smoke

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High-Frequency RadioA fast transmission medium for distances up to 40 kilometers, depending on obstructions. Attenuation is very low but is susceptible to EMI and eavesdropping. Applications of this technology include pagers, cellular phones, and Wi-Fi

High-Frequency RadioA fast transmission medium for distances up to 40 kilometers, depending on obstructions. Attenuation is very low but is susceptible to EMI and eavesdropping. Applications of this technology include pagers, cellular phones, and Wi-Fi

PagersA one way, wireless messaging system in multiple typesPagersA one way, wireless messaging system in multiple types

Cellular PhoneA two-way wireless communication that assigns unique frequencies to calls and can transmit in analog or digital

Cellular PhoneA two-way wireless communication that assigns unique frequencies to calls and can transmit in analog or digital

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Wireless LANs or Wireless Fidelity (Wi-Fi)Based on a standard called 802.11, this technology enables multiple computers to share Internet access, files, and peripheral devices

Wireless LANs or Wireless Fidelity (Wi-Fi)Based on a standard called 802.11, this technology enables multiple computers to share Internet access, files, and peripheral devices

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Networking Fundamentals – Media (Microwave)

MicrowaveA high frequency radio signal that is sent through the air using either terrestrial (earth-based) or satellite systems

MicrowaveA high frequency radio signal that is sent through the air using either terrestrial (earth-based) or satellite systems

Terrestrial MicrowaveA line-of-site technology (unobstructed) used to cross inaccessible terrain or to connect buildings where cable installation would be expensive. Attenuation is low over short distance but higher over longer distances, and high winds, heavy rain, EMI and eavesdropping are also problems

Terrestrial MicrowaveA line-of-site technology (unobstructed) used to cross inaccessible terrain or to connect buildings where cable installation would be expensive. Attenuation is low over short distance but higher over longer distances, and high winds, heavy rain, EMI and eavesdropping are also problems

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Networking Fundamentals – Media (Microwave)

Satellite MicrowaveA line-of-site technology that uses relay stations to transfer signals between antennae located on earth and a satellite orbiting the earth. It can be used to access the very remote locations and like a terrestrial microwave, attenuation, EMI and eavesdropping are also problems

Satellite MicrowaveA line-of-site technology that uses relay stations to transfer signals between antennae located on earth and a satellite orbiting the earth. It can be used to access the very remote locations and like a terrestrial microwave, attenuation, EMI and eavesdropping are also problems

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Wireless Media Benefits and Drawbacks

Comparisons of Wireless Media

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Network Hardware and Software (Network Topologies)

Network TopologiesRefers to the shape of a network and comes in three types:

Network TopologiesRefers to the shape of a network and comes in three types:

Star NetworkThe network is configured in the shape of a star with all nodes or workstations connected to a central hub, or concentrator, through which all messages pass

Star NetworkThe network is configured in the shape of a star with all nodes or workstations connected to a central hub, or concentrator, through which all messages pass

Ring NetworkThe network is configured in the shape of a circle with each node connecting to the next node. Messages travel around the circle in one direction. Each node examines the message and uses it or regenerates it and passes it to the next node

Ring NetworkThe network is configured in the shape of a circle with each node connecting to the next node. Messages travel around the circle in one direction. Each node examines the message and uses it or regenerates it and passes it to the next node

Bus NetworkThe network is configured in the shape of an open-ended line with all nodes or workstations connected to the bus individually.

Bus NetworkThe network is configured in the shape of an open-ended line with all nodes or workstations connected to the bus individually.

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Network Hardware and Software (Network Topologies)

Star Network

Ring Network

Bus Network

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Network Hardware and Software (Protocols)

ProtocolsAgreed-upon formats for transmitting data between connected computers

ProtocolsAgreed-upon formats for transmitting data between connected computers

Open Systems Interconnection (OSI)Is a protocol that represents a group of tasks as seven successive layers that allow computers to communicate

Open Systems Interconnection (OSI)Is a protocol that represents a group of tasks as seven successive layers that allow computers to communicate

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Network Hardware and Software (Hardware)

Connectivity HardwareThe hardware that allows computers to be physically connected to different types of networks

Connectivity HardwareThe hardware that allows computers to be physically connected to different types of networks

Common Connectivity Hardware• Connectors • Network Interface Cards (NICs)• Modems• Repeaters• Hubs• Bridges• Multiplexers• Routers• Gateways

Common Connectivity Hardware• Connectors • Network Interface Cards (NICs)• Modems• Repeaters• Hubs• Bridges• Multiplexers• Routers• Gateways

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ConnectorsUsed to terminate cables in order to be plugged into a network interface card or another network component

ConnectorsUsed to terminate cables in order to be plugged into a network interface card or another network component

Network Interface CardA PC expansion board with its own unique identifier that plugs into a computer allowing it to be connected to a network

Network Interface CardA PC expansion board with its own unique identifier that plugs into a computer allowing it to be connected to a network

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Modem (Modulator/Demodulator)Enables computers to connect and transmit data over phone lines by converting the sending computer’s digital signals to analog and back again for the receiving computer

Modem (Modulator/Demodulator)Enables computers to connect and transmit data over phone lines by converting the sending computer’s digital signals to analog and back again for the receiving computer

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RepeaterA network device used to regenerate or replicate a signal as it weakens when traveling across a network

RepeaterA network device used to regenerate or replicate a signal as it weakens when traveling across a network

HubsA central point of connection between media segments enabling network extension to accommodate more PCs

HubsA central point of connection between media segments enabling network extension to accommodate more PCs

BridgesUsed to connect two different LANs or two segments of the same LAN by forwarding traffic between segments

BridgesUsed to connect two different LANs or two segments of the same LAN by forwarding traffic between segments

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RouterAn intelligent device used to connect two or more individual networks. When it receives a signal, it looks up the address and passes it to the appropriate network

RouterAn intelligent device used to connect two or more individual networks. When it receives a signal, it looks up the address and passes it to the appropriate network

GatewaysThis device performs a protocol conversion so that different networks can communicate even though they speak different languages

GatewaysThis device performs a protocol conversion so that different networks can communicate even though they speak different languages

MultiplexerUsed to share a communications line among a number of users by converting and combining signals from multiple users for simultaneous transmission over a single line

MultiplexerUsed to share a communications line among a number of users by converting and combining signals from multiple users for simultaneous transmission over a single line

Networking - Information Technology

Documents

network interface

local area

personal area

networking

transmission

network topologies

distributed