Download - Presentation On Computer Network
A network consists of 2 or more computers
connected together, and they can communicate
and share resources (e.g. information)
Network Benefits
1.Ease Of Access
2.Work From Home
3.Share Resources
4.Share Information
5.Increase Productivity
6.Share Programs
7.Administration
8.Security
Transmission MediaTwo main categories:
Guided ― wires, cables
Unguided ― wireless transmission, e.g. radio, microwave, infrared, sound, sonarTwisted-Pair cables: Unshielded Twisted-Pair (UTP) cablesShielded Twisted-Pair (STP) cables
Coaxial cablesFiber-optic cables
Types Of NetworksTwo types of networks are LAN and WAN:
#. LAN (Local Area Network) – A group of devices
sharing resources in a single area such as a room or a
building.
#. MAN (Metropolitan Area Network) – Collection
of local area network sharing information in
geographical area such as a city or town.
#. WAN (Wide Area Network) – Two or more LANs
communicating, often across large distances. The
most famous WAN is the Internet.
• Local Area Network (LAN)• Small network, short distance
•A room, a floor, a building
•Limited by no. of computers and distance covered
•Usually one kind of technology throughout the LAN
•Serve a department within an organization
• Examples:
•Network inside the Student Computer Room
•Network inside CF502
•Network inside your home
• Metropolitan Area Network (MAN)
• It is a collection of local area network.
• Geographical Area :- City, Town
Example
• Branches of local bank of city
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• Wide Area Network (WAN)
• A network that uses long-range telecommunication links to connect 2 or more LANs/computers housed in different places far apart.
• Towns, states, countries
• Examples:
• Network of our Campus
• Internet
WAN
Student Computer Centre
Your home
USA
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Topology ― 3 basic types
• How so many computers are connected together?
Bus Topology Ring Topology
Star Topology
Hub
• Bus Topology•Simple and low-cost•A single cable called a trunk (backbone, segment)•Only one computer can send messages at a time•Passive topology - computer only listen for, not
regenerate data
• Star Topology•Each computer has a cable connected to a single point
•More cabling, hence higher cost
•All signals transmission through the hub; if down, entire network down
•Depending on the intelligence of hub, two or more computers may send message at the same time
• Ring Topology• Every computer serves as
a repeater to boost signals
• Typical way to send data:
•Token passing
•only the computer who
gets the token can send
data
• Disadvantages
•Difficult to add computers
•More expensive
• If one computer fails, whole network fails
Network Protocol – Specifications that define the network data
communication procedures to follow when sending and receiving
data.
1. TCP/IP (Transport Control Protocol / Internet Protocol) –
the most common network protocol used by most companies
and home users as a standard protocol. Used to access the
Internet.
2. IPX/SPX (Internetwork Packet Exchange/Sequenced
Packet Exchange) – original protocol used for connecting to
Novell networks. Now TCP/IP is the standard protocol used.
3. NetBEUI (NetBIOS Enhanced User Interface) – is a non-
routable protocol used in simple networks; commonly found
on peer-to-peer networks.
4. HTTP (Hypertext transfer protocol) – It is a set of rules for
transferring files (text, graphic images, sound, video, and
other multimedia files) on the World Wide Web.