networking introduction
TRANSCRIPT
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.
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.
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.
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.
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.