1. C-1 Appendix C Networking www.pearsoned.ca/jessup Robert Riordan, Carleton University

2. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-2 Human Communication Messages Human communication involves the sharing of information between senders and receivers. The information is shared in the form of a message. Sender Initiates the message by formulating the message content in the brain and coding the message in a form that can be communicated to the receiver (e.g. voice) Sender Initiates the message by formulating the message content in the brain and coding the message in a form that can be communicated to the receiver (e.g. voice) Receiver Uses their receiving mechanism (e.g. eyes, ears) to receive the encoded message and then attempts to decode its content or requests the message be resent Receiver Uses their receiving mechanism (e.g. eyes, ears) to receive the encoded message and then attempts to decode its content or requests the message be resent Communication Pathway

3. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-3 Human Communication Example

4. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-4 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) Protocols Procedures, rules, or standards must be followed by computers when sending or receiving data Protocols Procedures, rules, or standards must be followed by computers when sending or receiving data

5. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-5 Communication (Human versus Computer)

6. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-6 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 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 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

7. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-7 Types of Computing Distributed Computing Collaborative Computing Centralized Computing

8. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-8 Types of Networks Networks Most networks utilize a combination of computing models that have evolved over time and are connected by one or more of the following network types: Private Branch Exchange (PBX) Local Area Network (LAN) Wide Area Network (WAN) Global Networks Enterprise Network Value-added Network (VAN) Metropolitan Network (MAN) Personal Area Network (PAN) Networks Most networks utilize a combination of computing models that have evolved over time and are connected by one or more of the following network types: Private Branch Exchange (PBX) Local Area Network (LAN) Wide Area Network (WAN) Global Networks Enterprise Network Value-added Network (VAN) Metropolitan Network (MAN) Personal Area Network (PAN)

9. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-9 Private Branch Exchange PBX A telephone system serving a location by connecting one telephone line to another then to an outside telephone network. Can also connect PCs, fax, but at low phone- cable speeds PBX A telephone system serving a location by connecting one telephone line to another then to an outside telephone network. Can also connect PCs, fax, but at low phone- cable speeds

10. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-10 Network Types – Local Area Network Local Area Network (LAN) A 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 Network (LAN) A 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)

11. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-11 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 Global A WAN that spans multiple countries and may include the networks of several organizations (e.g. the Internet) Global A 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

12. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-12 Types of Networks – Wide Area Networks (WAN) Enterprise Network & MAN Enterprise A WAN that is the result of connecting the disparate networks of a single organization Enterprise A 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

13. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-13 Types of Networks – Personal Area Network (PAN) Personal Area Network (PAN) An emerging technology that uses wireless communication to exchange data between commputing devices using short-range radio communication (Bluetooth), typically within an area of ten meters Bluetooth Is 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

14. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-14 Networking Fundamentals – Servers and Clients Server Any computer on a network that makes access to files, printing, communication, and other services available to users on the network Server Any computer on a network that makes access to files, printing, communication, and other services available to users on the network Client Any 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 Client Any 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 Network A network consists of three separate components: servers, clients and peers Network A network consists of three separate components: servers, clients and peers

15. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-15 Networking Fundamentals – Peers Peer A computer that may both request and provide services Peer A 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)

16. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-16 Networking Fundamentals - Network Services Network Services The capabilities that networked computers share through their multiple combinations of hardware and software Network Services The capabilities that networked computers share through their multiple combinations of hardware and software File Services (a) The capabilities that networked computers share through their multiple combinations of hardware and software File Services (a) The capabilities that networked computers share through their multiple combinations of hardware and software 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.

17. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-17 Networking Fundamentals - Network Services 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

18. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-18 Networking Fundamentals – Transmission Media Transmission Media The physical pathway to send data and information between two or more entities on the network. Characteristics of the media include the following: Transmission Media The physical pathway to send data and information between two or more entities on the network. Characteristics of the media include the following: Bandwidth Is the transmission capacity of a communications channel or computer, measured in megabits per second (Mbps) (amount of binary data transmitted per second) Bandwidth Is the transmission capacity of a communications channel or computer, measured in megabits per second (Mbps) (amount of binary data transmitted per second)

19. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-19 Networking Fundamentals – Media (Cable) Twisted Pair (TP) Two 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 Pair (TP) Two 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 Coaxial (COAX) Contains a solid inner copper conductor surrounded by insulation and outer braided copper or foil shield. It is higher capacity than twisted pair Coaxial (COAX) Contains a solid inner copper conductor surrounded by insulation and outer braided copper or foil shield. It is higher capacity than twisted pair Fiber-Optic Made 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-Optic Made 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

20. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-20 Networking Fundamentals – Media (Cable)

21. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-21 Networking Fundamentals – Media (Wireless) Wireless A 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 Wireless A 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-Sight Uses 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-Sight Uses 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

22. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-22 Networking Fundamentals – Media (Wireless) High-Frequency Radio A 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 Radio A 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 Pagers A one way, wireless messaging system in multiple types Pagers A one way, wireless messaging system in multiple types

23. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-23 Networking Fundamentals – Media (Wireless) Cellular Phone A two-way wireless communication that assigns unique frequencies to calls and can transmit in analog or digital Cellular Phone A two-way wireless communication that assigns unique frequencies to calls and can transmit in analog or digital

24. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-24 Networking Fundamentals – Media (Wireless) 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

25. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-25 Networking Fundamentals – Media (Microwave) Microwave A high frequency radio signal that is sent through the air using either terrestrial (earth-based) or satellite systems Microwave A high frequency radio signal that is sent through the air using either terrestrial (earth-based) or satellite systems Terrestrial Microwave A 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 Microwave A 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

26. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-26 Networking Fundamentals – Media (Microwave) Satellite Microwave A 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 very remote locations and, like a terrestrial microwave, attenuation, EMI and eavesdropping are also problems Satellite Microwave A 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 very remote locations and, like a terrestrial microwave, attenuation, EMI and eavesdropping are also problems

27. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-27 Networking Fundamentals – Media (Wireless) Wireless Media Benefits and Drawbacks Comparisons of Wireless Media

28. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-28 Network Hardware and Software (Media Access Control) Media Access Control The set of rules that govern how a given node or workstation gains access to the network to send or receive information. Media Access Control The set of rules that govern how a given node or workstation gains access to the network to send or receive information. Media Access Control Types Distributed Access Control – the most common method of distributed access control is token passing. This method uses a constantly circulating electronic token (a small packet of data) to prevent collisions and give workstations equal access to the network Random Access Control – the most common method of random access control is called carrier sense multiple access/collision detect (CSMA/CD). In CSMA/CD each workstation listens to the network to determine whether a message is being transmitted. If quiet, the workstation transmits its message; otherwise it waits Media Access Control Types Distributed Access Control – the most common method of distributed access control is token passing. This method uses a constantly circulating electronic token (a small packet of data) to prevent collisions and give workstations equal access to the network Random Access Control – the most common method of random access control is called carrier sense multiple access/collision detect (CSMA/CD). In CSMA/CD each workstation listens to the network to determine whether a message is being transmitted. If quiet, the workstation transmits its message; otherwise it waits

29. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-29 Network Hardware and Software (Network Topologies) Network Topologies Refers to the shape of a network and comes in three types: Network Topologies Refers to the shape of a network and comes in three types: Star Network The 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 Network The 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 Network The 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 Network The 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 Network The network is configured in the shape of an open-ended line with all nodes or workstations connected to the bus individually. Bus Network The network is configured in the shape of an open-ended line with all nodes or workstations connected to the bus individually.

30. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-30 Network Hardware and Software (Network Topologies) Star Network Ring Network Bus Network

31. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-31 Network Hardware and Software (Protocols) Protocols Agreed-upon formats for transmitting data between connected computers Protocols Agreed-upon formats for transmitting data between connected computers Open Systems Interconnection (OSI) Is a protocol that represents a group of tasks (below) as seven successive layers that allow computers to communicate Open Systems Interconnection (OSI) Is a protocol that represents a group of tasks (below) as seven successive layers that allow computers to communicate

32. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-32 Network Hardware and Software (Protocols)

33. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-33 Network Hardware and Software (Protocols)

34. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-34 Network Hardware and Software (Hardware) Connectivity Hardware The hardware that allows computers to be physically connected to different types of networks Connectivity Hardware The 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 Brouters Channel Service Units Gateways Common Connectivity Hardware Connectors Network Interface Cards (NICs) Modems Repeaters Hubs Bridges Multiplexers Routers Brouters Channel Service Units Gateways

35. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-35 Network Hardware and Software (Hardware) Connectors Used to terminate cables in order to be plugged into a network interface card or another network component Connectors Used to terminate cables in order to be plugged into a network interface card or another network component Network Interface Card (NIC) A PC expansion board with its own unique identifier that plugs into a computer allowing it to be connected to a network Network Interface Card (NIC) A PC expansion board with its own unique identifier that plugs into a computer allowing it to be connected to a network

36. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-36 Network Hardware and Software (Hardware) 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

37. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-37 Network Hardware and Software (Hardware) Hub A central point of connection between media segments enabling network extension to accommodate more PCs Hub A central point of connection between media segments enabling network extension to accommodate more PCs Bridge Used to connect two different LANs or two segments of the same LAN by forwarding traffic between segments Bridge Used to connect two different LANs or two segments of the same LAN by forwarding traffic between segments Router An 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 Router An 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

38. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-38 Network Hardware and Software (Hardware) Repeater A network device used to regenerate or replicate a signal as it weakens (attenuates) while traveling on a network Repeater A network device used to regenerate or replicate a signal as it weakens (attenuates) while traveling on a network Hub A central point of connection between media segments enabling network extension to accommodate more PCs Hub A central point of connection between media segments enabling network extension to accommodate more PCs Bridge Used to connect two different LANs or two segments of the same LAN by forwarding traffic between segments Bridge Used to connect two different LANs or two segments of the same LAN by forwarding traffic between segments Router An 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 Router An 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

39. Information Systems Today, 2/C/e ©2008 Pearson Education Canada Appendix C-39 Network Hardware and Software (Hardware) Brouter Short for bridge router and provides the functions of both Brouter Short for bridge router and provides the functions of both Channel Service Unit A device that acts as a buffer between a LAN and a public carrier’s WAN to ensure signals placed on the public lines are appropriately timed and formed for the network Channel Service Unit A device that acts as a buffer between a LAN and a public carrier’s WAN to ensure signals placed on the public lines are appropriately timed and formed for the network Gateways This device performs a protocol conversion so that different networks can communicate even though they speak different languages Gateways This device performs a protocol conversion so that different networks can communicate even though they speak different languages Multiplexer Used 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 Multiplexer Used 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