Introduction To Network

Overview

• What’s Network ?• Types of Networks• Open System Interconnection Reference Model

(OSI / RM)• Transmission Control Protocol / Internet Protocol

(TCP/IP)• Network Devices• Network Topology• Cabling LAN

What’s Network?

• Network is a group of computers connected with others to share data.

Types of Network

1. Local Area Network (LAN) is a group of computers connected with others across limited geographic area.

2. Wide Area Network (WAN) is a group of computers connected with others across large geographic area.

3. Metropolitan Area network (MAN) is a network that spans a metropolitan area such as a city.

4. Storage Area network (SAN) is a dedicated, high-performance network used to move data between servers and storage resources.

5. Virtual Private Network (VPN) is a private network that is constructed within a public network infrastructure such as the Internet.

6. Intranets and Extranets.

OSI Reference Model

• Characteristics of OSI/RM– It contains seven layers.– Each layer has a specific function.– Each layer communicates with its own upper and

lower layer.– Each layer has some network devices operate on it.– Each layer has some network protocols operate on it.

• Benefits of the OSI Model– Defines the process for connecting two layers. – Separates a complex function into simpler

components.– Accelerates evolution.

OSI Reference Model

OSI Reference Model

OSI Reference Model

• Data Encapsulation means data wrapped with protocol information at each layer of the OSI model.

• To communicate and exchange information, each layer uses Protocol Data Units (PDUs).

OSI and TCP/IP

OSI Reference Model

Network Topology

• Network topology defines the structure of the network.• Logical topology defines how the media is accessed by

the hosts for sending data. • Physical topology is the actual layout of the wire or media.

Network Media

• Copper Media

• Optical Media

• Wireless Media

Copper Media

Copper Media

• Coaxial cable support Ethernet (10 Mbps) and FastEthernet (100 Mbps) there are two types of coaxial cable.– Thicknet: maximum length 500 m.– Thinnet: maximum length 185 m.

Copper Media

• Twisted Pair cable

Copper Media

• Twisted Pair cable

Copper Media

• Twisted Pair cable

Ethernet Cabling

• The types of Ethernet cables available are:1. Straight-through cable

2. Crossover cable

3. Rolled cable

Straight-through cable

• The straight-through cable is used to connect Host Switch Host Hub Router Switch Router Hub

Rolled Cable

• It isn’t used to connect any Ethernet connections together.

• It uses only for making a configuration for routers or switches.

Optical Media

• Fiber-optic cabling is typically used to provide very high speeds and to span connections across very large distances. For example, speeds of 100Gbps and distances of over 10 kilometers

• Fiber cabling is not affected by electromagnetic interference (EMI), whereas copper cabling is.

Optical Media

Wireless Media