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ITGS Networks. Based on the textbook “Information Technology in a Global Society for the IB Diploma” by Stuart Gray. Networks. Due to computer and smart phone growth, networks are becoming increasingly important due to the wireless options.
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ITGS Networks Based on the textbook “Information Technology in a Global Society for the IB Diploma” by Stuart Gray
Networks • Due to computer and smart phone growth, networks are becoming increasingly important due to the wireless options. • Computer networks exist in many places; small = at home with a few computers; large = companies with thousands of computers.
Network Components • Clients and servers • Shared devices • Hubs, routers and switches
Network Architecture • The way computers are organized on a network and the role each takes. • Thin Client Network – computers rely heavily on a server not only for storage but to run software. • Peer-to-peer Networks – Every client has equal status and there is no central authority or server.
Firewalls • Hardware or software that determines which data is allowed to enter and leave a network. • Personal firewall – when a software firewall in installed on a desktop computer versus a server. • IP Addresses • Domain Names • Protocols and Ports • Application Program
Proxy Servers • Middle step between 2 computers – usually between a computer on a LAN and a web server on the internet. • Caching – Process used to speed up activities such as web browsing.
Server Types • Local Area Network (LAN) – confined to 1 geographic area ex: home, school campus; can be wireless LANs • Personal Area Network (PAN) – when mobile devices are connected to a computer • Metropolitan Area Network (MAN) – Covers large areas ex: cities or large campuses
Server Types continued • Wide Area Networks (WAN) – Connecting many computers and LANs together ex: internet • Storage Area Networks (SAN) – Dedicated to storing data • Virtual Private Networks (VPN) – Uses encryption over a public network; Virtual LAN (VLAN)
Network Connections • Wired – Fiber optic cables, cable internet access, Dialup, Ethernet • Wireless – Wimax, Wi-Fi, Bluetooth, 3G and 4G • NOTE: Network speeds are measured in bits per second.
Network Communication • MAC Addresses (hardware address) – each is unique. • Protocols – Set of rules on how to do something. • IP (Internet Protocol) – how devices on the internet are identified and info is routed. • TCP (Transmission Control Protocol) – Deals with if data is sent and received. • Ports – Identify the services available on networked computers.
How are IP Addresses Assigned? • All IP Addresses are managed by IANA – the Internet Assigned Numbers Authority. • Dynamic – changes each time you connect. • Static – remains the same each time you connect. • Geolocation – implications for privacy – impossible to maintain anonymity on the Internet. • IP Address Future – 243 million are assigned a year – new standard adopted IPv6 (128 bit addresses).
The Internet • The Internet Backbone – series of high speed links which connect major geographical areas. • Data routing – infrastructure of the Internet. • Domain Name System (DNS) – responsible for translating domain names when people type in their web browsers into IP addresses.
Internet Protocols • Hypertext Transfer Protocols (HTTP) – governs communication between web servers and web browsers. • Hypertext Transfer Protocol Secure (https) – Designed to keep communication secure through encryption. • TLS • SSL
Internet Protocols continued • When data is transferred between computers: • Asynchronous Transfer – the sender and received are not synchronized in terms of time. • Synchronous Transfer – the sender and receiver agree on a transfer rate before the start of a transfer = faster data transfer.
Web 2.0 • Web sites that allow users to contribute information as well as view it. • Sometimes called read/write web: • Blogs or microblogs • Wikis • Social bookmarking • Social networks • RSS • Podcasts and Vodcasts • Web 3.0 – the next evolution – what will it look like?