1 / 24

WHAT IS THE INTERNET?

WHAT IS THE INTERNET?. IT IS NOT OWNED BY ANYONE IT IS NOT HOMOGENEOUS NO CENTRALIZED MANAGEMENT OVERSIGHT ORGANIZATIONS. WHAT IS THE INTERNET?. PROVIDES COMMUNICATIONS SERVICES E-MAIL FILE TRANSFER ONLINE CHAT AUDIO & VIDEO WORLD WIDE WEB INTERLINKED WEB PAGES SEARCH

tal
Télécharger la présentation

WHAT IS THE INTERNET?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WHAT IS THE INTERNET? IT IS NOT OWNED BY ANYONE IT IS NOT HOMOGENEOUS NO CENTRALIZED MANAGEMENT OVERSIGHT ORGANIZATIONS

  2. WHAT IS THE INTERNET? • PROVIDES COMMUNICATIONS SERVICES • E-MAIL • FILE TRANSFER • ONLINE CHAT • AUDIO & VIDEO • WORLD WIDE WEB • INTERLINKED WEB PAGES • SEARCH • INSTANT MESSAGING • E-SHOPPING

  3. WHAT IS THE INTERNET? IT IS: • COMPLEX • WORLDWIDE • PUBLICLY ACCESSIBLE • PACKET SWITCHING XMISSION TECHNOLOGY • HAS INTERCONNECTED NETWORKS • DOMESTIC • ACADEMIC • BUSINESS • GOVERNMENT • COMMERCIAL

  4. INTERNET HISTORY • 1957 SPUTNIK • 1958 DOD-ARPA, ADVANCED RESEARCH PROJECT AGENCY FORMED • 1965 1st EMAIL, TIMESHARE TO MAINFRAME COMPUTER • OCT. 1968 ARPANet WORKING GROUP MET AT SRI • NOV. 1969 ARPANET UCLA-SRI COMPUTER LINK ESTABLISHED • DEC. 1969 UCLA-SRI-UCSB-UofUTAH LINK-UP • 1971 1ST NETWORK E-MAIL TRANSMITTED BETWEEN COMPUTERS • 1973 FTP PROTOCOL INTRODUCED/IMPLEMENTED BY ARPANet • 1973 ROBT. KAHN & VINTON CERF BEGAN WORK ON TCP/IP • 1975 1ST COMMUNICATION TEST USING TCP/IP • 1975 ARPA TURNED ARPANet OVER TO DCA • 1978 PACKET SWITCHED NETWORKS EXPANDED TO EUROPE

  5. INTERNET HISTORY – CONTD. • 1979 CompuServ OFFERS E-MAIL SERVICE • 1981 NETWORKS EXPANDED TO CANADA, HONG KONG, & AUSTRALIA • 1982 TCP/IP ADOPTED FOR ALL MILITARY COMPUTER NETWORKS • 1983 - TCP/IP REPLACES PRIOR PROTOCOL USED BY ARPANet • - MILITARY PORTION OF ARPANet SPUN OFF TO MILNET • - DOMAIN NAME SYSTEM INVENTED • 1986 NATIONAL SCIENCE FND NETWORK(NSFNetwork) ON LINE REPLACING ARPANet • 1988 - NSFNet PRINCIPAL INTERNET BACKBONE WORLDWIDE • - NSFNet CREATED 5 SUPER CONDUCTOR CENTERS • - NSFNet WAS THE PRINCIPAL INTERNET BACKBONE • 1991 Tim Berners-Lee releases World-Wide Web (WWW) • 1993 MOSAIC (PRECURSOR TO NETSCAPE) MADE AVAILABLE TO PUBLIC • 1994 NSFNet traffic passes 10 trillion bytes/month • 1995 NSFNet DECOMMISSIONED; INTERNET TURNED OVER TO ISPs & TRANSMISSION CARRIERS

  6. PROTOCOLS RULES OR CONVENTIONS TCP (TRANSMISSION CONTROL PROTOCOL) – CONTROLS PACKAGING OF DATA INTO PACKETS AT SOURCE AND RECOMBINES DATA AT DESTINATION IP (INTERNET PROTOCOAL) – CONTROLS THE ROUTING OF DATA OVER THE INTERNET UDP (USER DATAGRAM PROTOCOL) – ALSO CONTROLS PACKAGING OF DATA INTO PACKETS SIMILAR TO, BUT NOT AS RELIABLY TRANSMITTED, AS TCP. USED FOR STREAMING AUDIO/VIDEO

  7. TCP/IP STACK LAYER

  8. INTERNET DOMAIN NAMEDOMAIN NAME racorinda@pacbell.net http://www.yahoo.com http://finance.yahoo.com.us/marketupdates/overview.html • 1st LABEL TO LEFT OF “/” IS THE TOP DOMAIN, GEOGRAPHICALLY us=U.S., ca=Canada, fr=France, de=Germany, ru=Russia, es=Spain, jp=Japan • 2nd LABEL TO LEFT IS THE TOP DOMAIN, GENERIC .biz, .com, .edu, .info, .net, .org, .info, .mil, .arpa, .museum • 3rd LABEL TO LEFT IS SECOND LEVEL DOMAIN • REMAINING LABELS TO LEFT ARE SUB-DOMAINS UNDER CONTROL OF THE SECOND LEVEL DOMAIN

  9. INTERNET DOMAIN NAMEIP ADDRESS

  10. DOMAIN NAME REQUEST ROOT SERVER IP Request: yahoo.com NAME SERVER FOR LOCAL ISP 2 22 3 Address For: yahoo.com 4 IP Request: Finance NAME SERVER FOR yahoo.com 1 5 IP Request: finance.yahoo.com/ Address For: Finance FINANCE SERVER AT YAHOO.COM 6 Communications Established 7 http://finance.yahoo.com/marketupdates/overview.html

  11. YAHOO.COM GATEWAY SERVER FIREWALL BRIDGE/SERVER FINANCE.YAHOO.COM SERVER YAHOO.COM NAME SERVER

  12. DATA PACKET • E-MAIL CLIENTWEB BROWSER • DATA HEADER <1500 BYTES • IP VERSION • HEADER LENGTH • PACKET PRIORITY, QUALITY OF SERVICE • PACKET LENGTH, BYTES • TAG TO HELP RECONSTRUCT PACKET • TAGS TO PERMIT FRAGMENTATION/MORE TO • FOLLOW? • FRAGMENT ORDER TAG • TIME TO LIVE BEFORE PACKET TO BE • DISCARDED • TRANSPORTATION PROTOCOL (E.G., TCP, UDP) • HEADER CHECKSUM • SENDER IP ADDRESS • DESTINATION ADDRESS • OPTIONAL TAGS

  13. PORTS – VIRTUAL ENTRANCEWAY BETWEEN YOUR COMPUTER & THE INTERNET TOTAL AVAILABLE PORTS = 65,535

  14. OUTGOING E-MAIL: SMTP Port 115 POP3 Port 110 SMTP W/SSL Port 465 POP 3 W/SSL Port 995 IF YOU USE A NON-STANDARD PORT YOU MUST SPECIFY THE PORT NUMBER BEING USED IN THE URL; E.G., http://www.parishilton.com:81/

  15. E-MAIL • METHOD OF WRITING, SENDING, RECEIVING AND SAVING MESSAGES USING AN ELECTRONIC COMMUNICATION SYSTEM • COMMON PROTOCOLS • - POP (POST OFFICE PROTOCOL): DELETES MSGS ON SERVER WHEN D/L • - IMAP (INTERNET MESSAGE ACCESS PROTOCOL): LEAVES MSGS ON SERVER • - WEBMAIL (HTTP PROTOCOL): ACCESS MAIL SERVER WITH BROWSER • - SMTP (SIMPLE MAIL TRANSFER PROTOCOL): STANDARD FOR OUTGOING MAIL • - PROPRIETARY PROTOCOLS: FOR INTRANET SYSTEMS, LIKE AOL/COMPANIES • - HTML (HYPERTEXT MARKUP LANGUAGE): MESSAGE BODY • - MIME (MULTIPURPOSE INTERNET MAIL EXTENSIONS): PERMITS TEXT OTHER • THAN ASCII, TEXT & NON-TEXT ATTACHMENTS, AND MULTIPLE PART MSGS.

  16. EMAIL TRANSMISSION DIAGRAM smtp.att.yahoo.com CLIENT HEADER PORT SMTP: 115/465 HTTP: 80 AOL: 531 Attach: BODY PORT POP3: 110/995 IMAP4:220/993

  17. WORLD WIDE WEB (www) or“The Web” SIR TIMOTHY BERNERS-LEE CREATED WEB TECHNOLOGY MARC ANDREESSEN CREATED THE FIRST BROWSER

More Related