computer network

1. By
Md.Ariful Islam
&
Md. Kausarul Alam Shuvo
Dept. of Computer Science &
Engineering
Jatiya Kabi Kazi Nazrul Islam
University

3.  The computer network was first use in 1950’s
decades . The idea of transferring data came
out at 1961 . Then the period of time it became
more developed . In 1969 University of
California , Los Angeles ( UCLA ) first
transferred data by using the computer
network .

5.  1. We can access programs and data from more
than one computer at the same time .
 2. We can sharing peripheral devices like
printers , scanners etc .
 3. Personal communications like E-mail .
 4. Making backup of information .
 5. Aiding communication by teleconferencing and
video-conferencing .
 6. Protecting information by account name and
password .
 And many other purposes .

6.  1. Local Area Networks (LANs)
2. Wide Area Networks (WANs)

7.  The major characteristics of LANs are given
below :
Multiple computers are connected together .
Computers are spread over a small geo-
graphical area .
Channels are of high capacity (Mbps , Gbps) .
Channels are relatively error free
(generally 1 error in 1,000,000,000 bits)

8. Network
operating
system
Other
Network
Network
Gateway
printer
Server
PC PC
PC
PC
Figure : A local area network .

9.  The special characteristics of WANs are
given below :
Multiple computers are connected together .
Computers are spread over a wide geo-
graphical area .
A WAN usually interconnects multiple
LANs
Links are of low capacity (low data rate) .
Bit error rate is higher than LAN (1 in 100,000) .

10. WAN
LAN
LANLAN
LAN
Individual
Computer
Figure : A wide area network .