Networking

Networking• The Field of Planning, Implementation,

Configuration, Monitoring and Maintenance the Networks is called as Networking.

• Network is a system of two or more interconnected computers that communicate with one another exchange information and can share applications, data and hardware components (resources).

Network

• Interconnected Nodes with the intention of exchanging information and Sharing the resources.

•Nodes: Devices/ Peripherals like Computer, Printer, Scanner, Switches and Routers etc.

•Resources: Files, Folders, Drives etc.

Advantages of Network

• It has many benefits. Some are following

• Sharing Information• Sharing Hardware Resources• Sharing Software resources• Preserving Information or Data• Personal communication

Disadvantages of Network

• Data leakage or less security• Virus Infection and loss of data• Distance• High cost of equipments• High cost of software or Network Operating

System• Experts are required

Categories OR Types of Network (Based on Area)

• Basically there are two type of computer network according to distance specially and also by hardware used.

• But other ones are also considered between them known as hybrid networks.

• LAN (Local Area Network)• WAN (Wide Area Network)• HYBRID NETWORKS

LAN (Local Area Network)• A LAN is a data communication system in which

two or more computers or devices are near to each other connected by cable or small radio transmitter (wireless media).

• It is widely used. • It is usually private i.e. used by a single

organization. • Computers called nodes/terminals/workstations

are connected in a few kilometer ranges or in a single building or floor or group of adjacent buildings.

WAN (Wide Area Network)• It consists of two or more computers,

which are apart from each other and are linked by networking.

• It is spread over countries and even continents over telecommunication lines.

• It used telephone lines, microwave or satellite. Example is Internet.

HYBRID NETWORKS• Between LANs and WANs we find hybrid networks.

New types of network are also emerging. Some are as follows

• MAN (Metropolitan Area Network): -They are bigger LANs. It covers few buildings or whole city. It might be private or public

• CANs (Campus Area Networks):- It is a large scale and more diversified LAN. With CAN different campus offices and organizations can be linked together.

• HANs (Home Area Networks):- It is contained within users home and connects his personal digital devices with different computers and their peripheral devices.

Types of Network (Based on Role of

computer) • According to role of computer , there

are three categories of network• Client /Server Networks• Peer (also called Peer-to-peer )• Hybrid Network

Client /Server Networks

• It contains clients and servers that support them.• Client: who request the recourses from the

server• Server: who provides resources, requested from

the client • In this system individual computers share the

processing and storage workload with central server.

• This arrangement requires special software for clients and servers

Peer (Peer-to-peer)

• It has no servers and use network to share hardware and software resources among independent peers.

Pros and consAdvantages of Server based Network• Strong central security, central file storage organization,

Sharing hardware and software by different rights levels. Disadvantages of Server based Network• Expensive hardware, expensive network operating system,

and administrator required.Advantages of Peer Network• Less expensive for small network, so extra hardware or

software required, easy to manage by any person and easy setup, not dependent on other computers.

Disadvantages of Peer Network• Limited number of users and take limited load, weak security

and lake of central management.Advantages of Hybrid Network• Advantages of both server and peer network.Disadvantages of Hybrid Network• All disadvantages of server based network.

Topologies

• A physical arrangement of wires or layout of cables that connect the computer or nodes of network in a LAN network is called topology.

• Or the way in which the connections in network are made is called topology of network.

• There are three basic topologies Bus, Star and Ring.

Bus Topology• In bus topology all computers are arranged

in a line or series to a single communication cable.

• Server can be places anywhere. • All nodes are attached to that wire. • All nodes can transmit data at a time. • It is cheaper because less wire is used and is

commonly used. • It has disadvantage that if any connection is

disconnected then whole network is down.

Bus Topology

Star topology

• It places a hub or switch in the center of nodes. • Data first goes to hub then to their

destinations. • Its advantage is that if a connection is broken

then other systems works without any disturbance.

• Easy for troubleshooting. • It is costly because more cables are required

and also requires a connecting device like hub.

Star Topology

Ring Topology

• It connects the network nodes in a circulate chain in which each node is connected to the next and final node connects to the first to complete the ring.

• Data flows in one direction, each node examines data if it is not for it passes it to next node.

• It is slower but no chance of collision of data as data flows in once direction.

• It requires more wire and also network disturb when ring breaks at any point.

Mesh topology

• In mesh each node is connected to all other nodes.

• They are easy to troubleshoot and fault tolerant.

• It makes network complex and more wire and devices are used and also difficult to install and configure.

• It is now out of use.

Mesh

Hybrid topologies• It is the combination of two or more

topologies. Most common are • Star bus combines bus and star

linking several star hubs together with bus.

• Star ring cables are arranges like star network but a ring of central hubs is made.

Star Ring

Star Bus Topology

Network Media or Communication Channels

• It is the medium or pathway through which data are transmitted between devices.

• It includes (a) wired media (b) Wireless media.

Wired media• Twisted pairs:-It consists of one or more

usually 4 or 8 copper strands of wire individually insulated in plastic then twisted around each other in pairs and bound together in another plastic insulation.

• It is used in telephone lines. • It may be UTP (Unshielded Twisted Pair)

with no cover. Or • STP (Shielded Twisted Pair). It is with cover• For a four-pair cable we need a RJ-45

connector used in computer network and for a two pair cable RJ-11connector used in telephone connectors.

Coaxial Cable

• It consists of copper or aluminum wire wrapped with insulating material.

• It allows high-speed data transmission. • It is used as television cable. • It uses BNC (Barrel Network Connector)

Fiber optics (glass wire)• It is sophisticated and fast channel that

transmits several billions bit per second. • It is 15 times faster than coaxial cable.• It uses hair like thin filaments of glass. • These filaments of glass, work on light pulses or

light flow in it.• They transmit light usually generated by LASER

or LED. • It is costly because wires and equipments to

install are costly. • Also experts and trained persons are required

for installation.

Wireless Media

• This media has no wire connection so transmission has low error and more reliable but it is expensive.

• Data can also be stolen easily. • As no wire is used so it can cover large area. • There are three main types of wireless

media. We can use satellite in it.• (i) Radio wave (ii) microwave and (iii)

infrared.