360 likes | 541 Views
Internet. Some slides taken from: Computer Science: An Overview Tenth Edition. J. Glenn Brookshear. Internet. Networks The Internet The World Wide Web Internet Protocols Security Search Engines. Network Classifications. Scope Local area network (LAN) Metropolitan area (MAN)
E N D
Internet Some slides taken from: Computer Science: An Overview Tenth Edition. J. Glenn Brookshear
Internet • Networks • The Internet • The World Wide Web • Internet Protocols • Security • Search Engines
Network Classifications • Scope • Local area network (LAN) • Metropolitan area (MAN) • Wide area network (WAN) • Ownership • Closed versus open • Topology (configuration) • Bus (Ethernet) • Star (Wireless networks with central Access Point)
The Internet • The Internet is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. • It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by a broad array of electronic and optical networking technologies.
Internet Architecture • Internet Service Provider (ISP) • Tier-1 • Tier-2 • Access ISP: Provides connectivity to the Internet • Traditional telephone (dial up connection) • Cable connections • DSL • Wireless
Internet Addressing • IP address: pattern of 32 or 128 bits often represented in dotted decimal notation • Mnemonic address: • Domain names • Top-Level Domains • Domain name system (DNS) • Name servers • DNS lookup
Internet Corporation for Assigned Names & Numbers (ICANN) • Allocates IP addresses to ISPs who then assign those addresses within their regions. • Oversees the registration of domains and domain names.
Traditional Internet Applications • Electronic Mail (email) • Domain mail server collects incoming mail and transmits outing mail • Mail server delivers collected incoming mail to clients via POP3 or IMAP • Mail clients • Outlook • Mozilla Thunderbird • File Transfer Protocol (FTP)
More Recent Applications • Voice Over IP (VoIP) • Internet Radio • N-unicast • Multicast
World Wide Web • Hypertext and HTTP • Browser gets documents from Web server • Documents identified by URLs
Hypertext Document Format • Encoded as text file • Contains tags to communicate with browser • Appearance • <h1> to start a level one heading • <p> to start a new paragraph • Links to other documents and content • <a href = . . . > • Insert images • <img src = . . . >
Extensible Markup Language (XML) • XML: A language for constructing markup languages similar to HTML • A descendant of SGML • Opens door to a World Wide Semantic Web
Using XML <staff clef = “treble”> <key>C minor</key> <time> 2/4 </time> <measure> < rest> egth </rest> <notes> egth G, egth G, egth G </notes></measure> <measure> <notes> hlf E </notes></measure> </staff>
Client Side Versus Server Side • Client-side activities • Examples: java applets, javascript, Macromedia Flash • Server-side activities • Common Gateway Interface (CGI) • Servlets • PHP
Security • Attacks • Malware (viruses, worms, Trojan horses, spyware, phishing software) • Denial of service • Spam • Protection • Firewalls • Spam filters • Proxy Servers • Antivirus software
Search Engines • General • Ask.com (formerly Ask Jeeves) • Baidu (Chinese) • Bing (formerly MSN Search and Live Search) • Cuil • Duck Duck Go • Google • Kosmix • Sogou (Chinese) • Sohu (Chinese) • Yahoo! Search • Yandex (Russian) • Yebol
Search Engines • Geographical limited scope • Accoona, China/US • Alleba, Philippines • Ansearch, Australia/US/UK/NZ • Baidu, China • Daum, Korea • Goo, Japan • Guruji.com, India • Leit.is, Iceland • Maktoob, Arab World • Onkosh, Arab World • Miner.hu, Hungary
Search Engines • Business • Business.com • GlobalSpec • Nexis (Lexis Nexis) • Thomasnet (United States)
Search Engines • Enterprise • AskMeNow: S3 - Semantic Search Solution • Concept Searching Limited: concept search products • Dieselpoint: Search & Navigation • dtSearch: dtSearch Engine(SDK), dtSearch Web • Endeca: Information Access Platform • Exalead: exalead one:enterprise • Expert System S.p.A.: Cogito • Fast Search & Transfer: Enterprise Search Platform (ESP), RetrievalWare (formerly Convera)
Search Engines • Other • Medical • News • People • News • Real Property • etc
Google Search • Advanced Search • Specify AND also with “ “ • Specify OR by writing OR • Unwanted words • Language • Format • File type • Pages in a domain
Google Search • Advanced Search • Date • Rights • Where keywords are • Region
Google Addwords Keyword Tool • How to make your page appear in high positions in Google Search? • Sword • Master Albania • Cars Albania • New York Tirana
Google Rankings • http://www.googlerankings.com/ • Check ranking • http://www.prchecker.info/ • www,unyt.edu.al • www.km.gov.al
Google Analytics • http://www.google.com/analytics/ • Adsense
Exam rules • Powerpoint 50 pts • Access 48 pts • Latex 2 pts • Only one formula with Latex material open