Networking
- 2. Computer network A collection of computing devices connected in order to communicate and share resources Connections between computing devices can be physical using wires or cables or wireless using radio waves or infrared signals 2
- 3. Node (host) Any device on a network Data transfer rate (bandwidth) The speed with which data is moved from one place to another on a network 3 Why is bandwidth so key?
- 4. Protocol A set of rules that defines how data is formatted and processed on a network; i.e., rules that allow client/server interaction File server A computer that stores and manages files for multiple users on a network Web server A computer dedicated to responding to requests (from the browser client) for web pages 4
- 5. Simultaneous access to data Data files are shared Access can be limited Shared files stored on a server Software can be shared Site licenses Application servers
- 6. Shared peripheral device Printers and faxes are common shares Reduces the cost per user Devices can be connected to the network Print servers control network printing Manage the print queue
- 7. File server contains documents used by other computers.
- 8. Personal communication Email Instantaneous communication Conferencing Tele conferencing Videoconferencing Audio-conferencing Data-conferencing Voice over IP Phone communication over network wires
- 10. Easier data backup Backup copies data to removable media Server data backed up in one step
- 11. Local Area Network (LAN) Contains printers, servers and computers Systems are close to each other Contained in one office or building Organizations often have several LANS
- 12. Wide Area Networks (WAN) Two or more LANs connected Over a large geographic area Typically use public or leased lines Phone lines Satellite The Internet is a WAN
- 13. Campus Area Networks (CAN) A LAN in one large geographic area Resources related to the same organization Each department shares the LAN
- 14. Metropolitan Area Network (MAN) Large network that connects different organizations Shares regional resources A network provider sells time
- 15. Home Area Network (HAN) Small scale network Connects computers and entertainment appliances Found mainly in the home
- 16. Personal Area Network (PAN) Very small scale network Range is less than 2 meters Cell phones, PDAs, MP3 players
- 17. Client/Server network Nodes and servers share data roles Nodes are called clients Servers are used to control access Database software Access to data controlled by server Server is the most important computer
- 18. Peer to peer networks (P2PN) All nodes are equal Nodes access resources on other nodes Each node controls its own resources Most modern OS allow P2PN Distributing computing is a form
- 19. Company's internal version of internet is called Intranet The major difference between internet and Intranet is that Intranet usually limits access to employees and selected contractors having ongoing business with the company An Extranet is a partially accessible internal company Website for authorized users physically located outside the organization
- 20. Topology Logical layout of wires and equipment Choice affects Network performance Network size Network collision detection Several different types
- 21. Packets Pieces of data transmitted over a network Packets are created by sending node Data is reassembled by receiving node Packet header Sending and receiving address Packet payload Number and size of data Actual data Packet error control
- 22. Bus topology Also called linear bus One wire connects all nodes Terminator ends the wires Advantages Easy to setup Small amount of wire Disadvantages Slow Easy to crash
- 23. Star topology All nodes connect to a hub Packets sent to hub Hub sends packet to destination Advantages Easy to setup One cable can not crash network Disadvantages One hub crashing downs entire network Uses lots of cable Most common topology
- 25. Ring topology Nodes connected in a circle Tokens used to transmit data Nodes must wait for token to send Advantages Time to send data is known No data collisions Disadvantages Slow One node fails all the network fails
- 26. Mesh topology All computers connected together Internet is a mesh network Advantage Data will always be delivered Disadvantages Lots of cable Hard to setup Formula to count number of links n(n-1)/2
- 27. Links that connect nodes Choice impacts Speed Security Size
- 28. Twisted-pair cabling Most common LAN cable Called Cat5 or 100BaseT Four pairs of copper cable twisted May be shielded from interference Speeds range from 1 Mbps to 1,000 Mbps
- 29. Coaxial cable Similar to cable TV wire One wire runs through cable Shielded from interference Speeds up to 10 Mbps Nearly obsolete
- 30. Fiber-optic cable Data is transmitted with light pulses Glass strand instead of cable Immune to interference Very secure Hard to work with Speeds up to 100 Gbps
- 31. Data transmitted through the air LANs use radio waves WANs use microwave signals Easy to setup Difficult to secure
- 32. Network interface cards Network adapter Connects node to the media Unique Machine Access Code (MAC)
- 33. Infra red The key component of an infrared system is an infrared LED (Light Emitting Diode) to emit the light and a photo-diode in the television or equipment to receive the light. Inexpensive compared to other technologies Only works line-of-light Works over a moderate bandwidth 115 kbps Short range - a few meters Works well over a short distance Low bandwidth
- 34. Bluetooth Bluetooth was standardized as IEEE 802.15.1 Invented by telecom vendor Ericsson in 1994 Range may vary depending on class of radio used in an implementation: Class 3 radios – have a range of up to 1 meter or 3 feet Class 2 radios – most commonly found in mobile devices – have a range of 10 meters or 33 feet Class 1 radios – used primarily in industrial use cases – have a range of 100 meters or 300 feet
- 35. Satellite Satellite is an artificial object which has been intentionally placed into orbit The world's first artificial satellite was launched by the Soviet Union in 1957 Low Earth orbit (LEO) Medium Earth orbit (MEO) Geosynchronous Orbit (GEO) High Earth Orbit (HEO)
- 36. Network linking devices Connect nodes in the network Cable runs from node to device Crossover cable connects two computers
- 37. Hubs Center of a star network All nodes receive transmitted packets Slow and insecure
- 38. Switches Replacement for hubs Only intended node receives transmission Fast and secure There are two types Manageable Unmanageable Divides broadcast domain Virtual LANs can be created
- 39. Bridge Connects two or more LANs together Packets sent to remote LAN cross Other packets do not cross Segments the network on MAC addresses
- 40. Router Connects two or more LANs together Packets sent to remote LAN Network is segmented by IP address Connect internal networks to the Internet Need configured before installation Routers allow different networks to communicate Router selects route for the packets
- 41. Gateway Connects two dissimilar networks Connects coax to twisted pair Most gateways contained in other devices
- 42. Cabling specifications Bandwidth measures cable speed Number of bits per second is called bandwidth Typically measured in Mbps Maximum cable length Connector describes the type of plug Example RJ 45, BNC (British Novel Connector),
- 43. Ethernet Very popular cabling technology 10 Base T, 10Base2, 10Base5 Maximum bandwidth 10 Mbps Maximum distances100 to 500 meters
- 44. Fast Ethernet Newer version of Ethernet Bandwidth is 100 Mbps Uses Cat5 or greater cable Sometimes called 100Base T Requires a switch
- 45. Gigabit Ethernet High bandwidth version of Ethernet 1 to 10 Gbps Cat 5 or fiber optic cable Video applications
- 46. Token ring Uses shielded twisted pair cabling Bandwidth between 10 and 25 Mbps Uses a multiple access unit (MAU) Popular in manufacturing and finance
- 47. Language of the network Rules of communication Error resolution Defines collision and collision recovery Size of packet Naming rules for computers
- 48. TCP/IP Transmission Control Protocol/Internet Protocol Most popular protocol Machines assigned a name of 4 numbers IP address 209.8.166.179 is the White House’s web site Dynamic Host Configuration Protocol Simplifies assignment of IP addresses Required for Internet access
- 49. IPX/SPX Internet Packet Exchange/Sequenced Packet Exchange Older protocol Associated with Novell Netware Replaced by TCP/IP
- 50. Modems Modulator/Demodulator Modulator converts digital to analog Speed measured in bits per second (bps) Quality of phone lines dictates speed Several modem types Internal External Voice Fax
- 51. Modem uses Connection to the Internet File transfer Uploading Downloading
- 52. Digital phone lines Local telephone companies are upgrading Service will faster and more reliable New phones will be needed Modems will need to be upgraded
- 53. Broadband connection Any data connection faster than 768 Kbps Common in business Becoming popular in home installations
- 54. Benefits No cable to pull Mobile devices access network resources Mobility and flexibility for office workers
- 55. Wireless 802.11 Also called Wi-Fi IEEE standard Institute of Electronic and Electrical Engineers Several versions 802.11b connects up to 11Mbps 802.11g connects up to 56Mbps Use the same type of devices
- 56. Wireless Access Point Center of a wireless network WAPS combined cover a larger area Distance to WAP determines bandwidth Range is 50 to 150 meters Extension points can extend range
- 57. Wireless Adapters Used by devices to connect Includes signal strength software
- 58. Network protocols are layered such that each one relies on the protocols that underlie it Sometimes referred to as a protocol stack 58 Figure Layering of key network protocols
- 59. Transmission Control Protocol (TCP) Software that breaks messages into packets, hands them off to the IP software for delivery, and then orders and reassembles the packets at their destination Internet Protocol (IP) Software that deals with the routing of packets through the maze of interconnected networks to their final destination 59
- 60. User Datagram Protocol (UDP) An alternative to TCP that is faster but less reliable Ping A program used to test whether a particular network computer is active and reachable Traceroute A program that shows the route a packet takes across the Internet 60
- 61. Other protocols build on TCP/IP protocol suite Simple Mail Transfer Protocol (SMTP) used to specify transfer of electronic mail File Transfer Protocol (FTP) allows a user to transfer files to and from another computer Telnet used to log onto one computer from another Hyper Text Transfer Protocol (http) allows exchange of Web documents 61
- 62. Firewall A gateway machine and its software that protects a network by filtering the traffic it allows Access control policy A set of rules established by an organization that specifies what types of network communication are permitted and denied 62 Have your messages ever been returned undelivered, blocked by a firewall?
- 63. 63 Figure A firewall protecting a LAN
- 64. Hostname A name made up of words separated by dots that uniquely identifies a computer on the Internet IP address An address made up of four one-byte numeric values separated by dots that uniquely identifies a computer on the Internet 64
- 65. 65 Figure An IP address is stored in four bytes What is wrong with the IP4 strategy? How did smartphones contribute to the problem?
- 66. 66 IPv4 32 bits in 4 groups of 8 bits IPv6 32 bits organized into 4 groups of 8 FE80:0000:0000:0000:0202:B3FF:FE1E:8329 They work in parallel
- 67. 67
- 68. Host number The part of the IP address that specifies a particular host (machine) on the network Yes, but what is it? Domain name The part of a hostname that specifies a specific organization or group 68
- 69. Class A N.H.H.H 1-126 0 can not be used as Net ID 127 is reserved for loop back functions 126 Different Networks 16.777.214 Hosts per Network
- 70. Class B N.N.H.H 128-191 The first IP Address is the NET ID The last IP Address is the Broadcast Address 16.384 Different Networks 65543 Hosts per Network
- 71. Class C N.N.N.H 192-223 The first IP Address is the NET ID The last IP Address is the Broadcast Address 2.097.152 Different Networks 254 Hosts per Network
- 72. CLASS D – Used for multicast broadcasts CLASS E – Experimental addresses not available to the public
- 73. 73 Figure Top-level domains, including some relatively new ones
- 74. Effects of Social Networking What are some examples of popular social networking sites? What are the benefits and the disadvantages of using these social networking sites? Do the benefits of social networking out weigh the potential costs? 74
- 76. Used to connect Mice and Keyboards to the computer
- 77. Used to connect older style Keyboards to the computer
- 78. Used to connect older Mice to the computer Also used for Network connections and for connecting devices such as Digital Cameras or PALM HostSyncs
- 79. Used to the Monitor to the computer (RGB stands for Red/Green/Blue)
- 80. Used to connect Joysticks, Game Controllers, and MIDIs (Musical Instrument Data Interface) to the computer
- 81. Used to connect Printers and Scanners to the computer
- 82. Universal Serial Bus Used to connect any type of device to the computer - Printer, Scanner, Mouse, Keyboard, MP3 Player,….
- 83. Used for Network Connections
- 84. Used for coaxial cable Network Connections
- 85. (Audio/Video Port) Used to connect Speakers, Microphones, and Headphones to the computer