INTERNET. INTERNET. Network of Networks Nobody owns it OS - No constraint TCP/IP Protocol VPN (Virtual Private Network) ISP INTRANET. Computer Telephone MODEM Account with ISP Browser Inclination. INTERNET. COORDINATING GROUPS OF INTERNET.
Internet Engineering Task Force (IETF) – Operation, Management, Evaluation & development of protocols
Internet Research Task Force (IRTF) – Long term research problems and technical issues
Internet Architecture Board (IAB) – Overlooks the functioning of IETF & IRTF and ratifies their proposals
Internet Society – Parent of IAB looks after overall promotion and usage of Internet in education, technical applications & new applications
DIAL-UP : For single intermittent user; uses normal telephone lines with a modem.
ON DEMAND : Mid range option; Like a dedicated connection but user has to dial through a modem or ISDN (64-128 kbps). ISDN allows both voice & data.
DEDICATED : For high volume use when No of users wish to simultaneously access Internet. Requires a router at the user end also. Option at different speeds are available.
ISP to INTERNET – T1 (1.544 Mbps) or T3 (45 Mbps)
INTERNET BACKBONE – 1000 Mbps
Network Operation Centre
Stand Alone PC
TERMINOLOGY OF INTERNET
BRIDGE – Connecting two NW operating with same OS
ROUTER - Connecting two NW operating with different OS
BROUTER – Plays both the roles of Bridge & Router
ISP – Connects End-users to Internet backbone
GATEWAY – A computer between ISP and Internet Router which connects the regional networks to Internet
INTERNET BACKBONE – High bandwidth fiber optic line with numbers of routers
General Format – Host Name . Second Level Domain Name . First Level Domain Name
Host Name – Service Provider Name
Domain Name – Kind of Organisation
Examples of Organisational & Geographic Domains
gov – Government Agencies
mil – Military site
com – Commercial organisation
net – Sites performing admin function
org – Non profit organisation
in – India us – USA
1. URL : It is networked extension of standard file name concept. The file and its directory can exist on any computer on the network. Format of URL
2. HTTP : Request – Response Actions of HTTP
(a) Browser uses HTTP commands to commn with HTTP server through a response provided by URL.
(b) A TCP/IP connection is established from client to the server.
(c) Browser sends a request to server typically for a file.
(d) Server sends a response message with the requested data.
(e) Connection is terminated after passing the message.
3. HTML : It is based on international electronic document standard called Standard Generalised Markup Language (SGML). Common basic language of interchange for hypertext documents. Doc creation by using control codes in ASCII to designate titles, headings, graphics & hypertext links. Doc size is small.
SHAREWARE. S/W AVAILABLE ON TRIAL BASIS.
FREEWARE. FREE S/W eg FONTS,CLIP ART & GAME.
UPGRADES. UPDATES & FIXES OF S/W.
DOCUMENTS. RESEARCH PAPERS, ARTICLES etc.
IT CARRIESOUT SEARCH IN DIFFERENT WAYS AND COME OUT WITH DIFFERENT RESULTS. EACH SEARCH ENGINE HAS ITS OWN DATA BASE.
IT SENDS THE ELCTRONIC CRAWLERS (CALLED SPIDERS, WORMS OR ROBOTS) THROUGH WEB LOOKING FOR PAGES TO ADD TO THEIR DATABASE OF EXISTING WEB PAGES. IT THEN ADDS THE NEW ENTRY TO THE DATABASE .
Distributed Hierarchical Naming System
Name is given by traversing the tree to its root
At each node a name is added and period (.) is appended
Each node can have any number child nodes but only one parent node
Each child node MUST have different name
Web Page Address WWW.Yahoo.com