very usefull to all

2. * A collection of computing devices that are connected
in various ways in order to communicate and share
resources
*Usually, the connections between computers in a
network are made using physical wires or cables
*some connections are wireless, using radio waves or
infrared signals

3. *The generic term node or
host refers to any device
on a network
Data transfer rate
*The speed with which
data is moved from one
place on a network to
another

4. T y p e s o f N e t w o r k s
*Local-area network(LAN)
*Wide-area network (WAN)
*Metropolitan-area
network (MAN)

5. Internet
*Communication between networks is called internet
*It connect the entire globe
Internet service provider (ISP)
*A company that provides other companies or
individuals with access to the Internet
for example
BSNL,Airtel,Idea and etc

6. Internet Connections
• (i) Gateway Access
• (ii) Dial-up Connection
• (iii) Leased Connection
• (iv) DSL
• (v) Modem Connection
• (vi) VSAT

7. Broadband
• DSL connections and modems are broadband
connections
• A connection in which transfer speeds are faster than
128 bits per second
• Downloads→getting data from the Internet to your
home computer or phone
• Uploads→sending data from your home computer to
the Internet

8. IP－Internet Protocol
* the routing of packets
TCP －Transmission
Control Protocol
* breaks messages into
packets and reassembles
the packets
* highly reliable

9. • UDP －User Datagram Protocol
* same as TCP
* It used in wireless communication
* less reliable, but generally faster
High-Level Protocols
–Simple Mail Transfer Protocol (SMTP)
–File Transfer Protocol (FTP)
–Telnet
–Hyper Text Transfer Protocol (HTTP)

11. • A machine and its software that serve as a special
gateway to a network, protecting it from inappropriate
access
– Enforces an organization’s access control policy

12. A firewall protecting a LAN

13. • Hostname
* That means website name in internet
For example
google.com.in
* hostname into its corresponding IP address
For example
205.39.145.18

14. • IP address can be split
*network address
－specifies a specific network
*host number
－particular machine in that network
* The domain name system (DNS) is chiefly used to
translate hostnames into numeric IP addresses
－ example
distributed database

15. DOMAINS
two-letter country codes

16. Other common domains