Lecture 4Title: Network Components and

Types

By: Mr Hashem AlaidarosMIS 101

Main PointsNetwork ComponentsPeer-to-Peer and Client-Server NetworkNetwork types: LAN, CAN, MAN, WANNetwork Topologies

Network• Networking and communication trends

• Convergence:• Telephone networks and computer networks converging into single digital

network using Internet standards

• Internet service provider (ISP): any company that provides individuals or organizations with access to the Internet

• Exercise: Draw the home network, starting from your PC to the Internet.

Network Components• Network: Two or more connected computers

• Major components in simple network• Client computer • Server computer

• Network operating system (NOS)

• Hub or switch

• Router

• Modem

• Network interface cards (NICs): acts as an intermediary between the computer and the network

• Connection medium: Cables or wireless for transmission

Network Components

Network Components• NOS: manages communication on the network and

coordinates network resources.

• Hub: a device that connect network components, sending data to all other connected device.

• Switch: is more intelligent than a hub, it filter and forward data to specified destination on the network

• Router: is a communication processor used to route data through different networks, ensuring that the data sent gets to the correct address.

Peer-to-Peer and Client-Server• There are two types of Networks in term of the relationship

between computers:• Peer-to-peer (P2P) network operating systems allow users to

share resources and files (locally or globally) located on their computers and to access shared resources found on other computers (Each computer has equivalent responsibilities).

• Client/server network operating systems allow the network to centralize functions and applications in one computer to serve the clients.

• What are the differences between Peer-to-Peer network and Client-Server network?

Peer-to-Peer

Client-Server

Peer-to-Peer• Advantages:

Easy to install Cheap No need administrator

• Disadvantages: Decentralized - No central repository for files and applications. Less secure Limitation- Work well with 10 computers or fewer

Client-Server• Advantages:

Centralized - Resources and data security are controlled and stored through the server.

Scalability – allow to increase the number of connected devices.

Flexibility - New technology (software) can be easily installed into computers.

More Secure. Why?

• Disadvantages: Not easy to install Expensive Not easy to maintain

Client-Server Clients linked through network controlled by network

server computer

Server sets rules of communication for network and provides every client with an address so others can find it on the network

The Internet: Largest implementation of client/server computing

Network typesTypes of Networks in term of size:

1. LAN2. CAN3. MAN4. WAN

What are the differences between them?

LANLAN:

Size: One building, roughly from 2 to 500 PCsExample: PSCJ college, a branch of a companyNeeded: Switch is needed to connect PCs and

ServersNo need: ISP connectionCan be peer-to-peer and client-serverIn Wireless LAN, it called WLAN, or Wifi

CANCampus Area Network (CAN):

Size: Two buildings and above, more than one LANs connected, maximum of 1 Kilo Meter.

Example:

MANMetropolitan Area Network (MAN)

Size: bigger than CAN, maximum up to a cityNeed: Routers and ISP are neededIn wireless connection, it called WiMax

WANWide Area Network (WAN)

Size: used for long distance, more than one city connected.

Example: WWW, BanksNeeds: Routers and global ISPs

Network TopologiesThere are three types of network topologies:1.Star Network2.Bus Network3.Ring Network

Network Topologies

Cont.• In a star topology

all devices on the network connect to a single hub and all network traffic flows through the hub

• In a bus topologyone station transmits signals, which travel in both

directions along a single transmission segment. All of the signals are broadcast in both directions to the

entire network. All machines on the network receive the same signals, and

software installed on the client’s enables each client to listen for messages addressed specifically to it

Cont.• A ring topology

connects network components in a closed loop. Messages pass from computer to computer in only one

direction around the loop, and only one station at a time may transmit.

The ring topology is primarily found in older LANs using Token Ring networking software