Networks : SI Rajesh http://tutor-desirachh.blogspot.com 1 Networks Computer network is the interconnection of various computer systems, located at same/ different places through communication links. This enables a user in one location to freely access a computer system, data base , process or software in another location
Requirements for Networking : SI Rajesh http://tutor-desirachh.blogspot.com 2 Requirements for Networking Communication Links (Wires, Cables, OFC, Satellites, Wireless devices etc).
Hub/Concentrator: A device through which computers are connected.
Switch: Intelligent Hub (Combination of Hardware & Software).
Router: Routes the packets of information to destined computer.
Bridge: Software or hardware that connects two or more networks so that they can communicate.
Gateway: Intelligent device capable of converting protocols used in various networks.
Compatible Software: For efficient working & use of networks.
Protocol: Set of agreed rules between two communicating computers.
NIC (Network Interface Card)/LAN Card: An essential hardware installed in computer which has a unique IP address.
Purposes of Networking : SI Rajesh http://tutor-desirachh.blogspot.com 3 Purposes of Networking Data Sharing: Can be done by using shared folder.
Information Interchange: E-mails may be used.
Device Sharing: Printers, Scanner, CDD may be shared.
Remote Login: System can be logged in remotely.
Advantages of Networking : SI Rajesh http://tutor-desirachh.blogspot.com 4 Advantages of Networking Reliability: A file may be available in any of the Networked Computer.
Less Cost: Due to Device sharing, less hardware is required.
Security: Passwords required to access any data from network.
Slide 5 : SI Rajesh http://tutor-desirachh.blogspot.com 5 Network Topology The way of interconnecting the computers is called Network Topology. It is also called architecture of network .
Node :- A computer connected to a network is known as node / terminal.
A computer that is not connected with any network is known as stand alone computer.
Types of Network Topologies : SI Rajesh http://tutor-desirachh.blogspot.com 6 Types of Network Topologies The Network Topologies are of following types
Ring Topology
Bus / Multi drop Topology
Star Topology
Mesh Topology
Hybrid Topology
Slide 7 : SI Rajesh http://tutor-desirachh.blogspot.com 7 . Both ends of the network must be terminated with a terminator. A barrel connector can be used to extend it.
Also Known as multi drop / multi point topology.
A single link is shared between many nodes
Each node has unique address.
All node will receive a message but only addressed node will respond.
If one node breaks down , network is still available for communication.
Lesser wires / lines are required . Bus Topology Bus Topology
Slide 8 : SI Rajesh http://tutor-desirachh.blogspot.com 8 Ring Topology Devices are connected from one to another, as in a ring. A data token is used to grant permission for each computer to communicate.
Information is divided into packets for transmission between nodes .
Each packet contains address of node that is to receive the information.
Used in local networking.
If a node fails whole the network breaks down .
Slide 9 : SI Rajesh http://tutor-desirachh.blogspot.com 9 Star Topology All devices connected around a central hub, which is what controls the network communications, and can communicate with other hubs.
Range limits are about 100 meters from the hub.
Effective communication between central node and outer nodes.
Not much effective when two or more outer nodes communicate .
If central node fails all network breaks down.
Mesh Topology : SI Rajesh http://tutor-desirachh.blogspot.com 10 Mesh Topology Mesh topologies involve the concept of routes.
The messages sent on a mesh network can take any of several possible paths from source to destination.
DTE: Data Terminal Equipment (Computers)
Hybrid Topology : SI Rajesh http://tutor-desirachh.blogspot.com 11 Hybrid Topology It is also known as Bus-Star Topology
Both the topologies (Bus & Star) are used in designing network.
Bus is called trunk or back bone of the network.
If the Bus is broken the entire network goes down.
If a single node fails the network is still alive.
Types of Networks : SI Rajesh http://tutor-desirachh.blogspot.com 12 Types of Networks According coverage area Networks may be classified as:
LAN (Local Area Network)
WAN (Wide Area Network)/GAN (Global Area Network)
MAN (Metropolitan Area Network)
CAN (Campus Area Network)
LAN (Local Area Network) : SI Rajesh http://tutor-desirachh.blogspot.com 13 LAN (Local Area Network) Network that connects computers in single room or building are called LAN
Range 300 Meter.
Digital Transmission of data with several Mbps.
Cable with multiple core for parallel transmission used.
Coaxial, Fiber Optical or Simple pair of wire used for serial transmission.
Modems are not required.
Star, Ring or Multi Drop topologies may be used.
Characteristics & Uses of LAN : SI Rajesh http://tutor-desirachh.blogspot.com 14 Characteristics & Uses of LAN Characteristics:
Inexpensive Transmission Media.
Less Cost of Equipments.
High Data Transmission Rate.
Uses:
Office work stations.
Mass storage devices/File Servers.
Printers & Plotters shared.
Remote Database Access.
WAN/GAN : SI Rajesh http://tutor-desirachh.blogspot.com 15 WAN/GAN Network connecting computers with in Regional, National or Global area.
Connects more than two LANs.
Gateways used for connecting LAN & WAN.
Data transfer speed is a few Mbps.
Modems are required.
Protocols, Error checking & correction means, Communication controllers (FEP) used.
FEP: Front End Processors
Signal boosters are required.
Links made through telephone lines, coaxial cables, Microwaves or satellite.
Slide 16 : SI Rajesh http://tutor-desirachh.blogspot.com 16 CAN (Campus Area Network): A network that connects the computer within a campus area. Like Universities campus, HAP Complex Campus Madhuban.
Range < 2/3 KMs.
MAN (Metropolitan Area Network): A network that connects computers of a metro city like Delhi, Bombay etc.
Range < 30/35 KMs.
Difference between LAN & WAN : SI Rajesh http://tutor-desirachh.blogspot.com 17 Difference between LAN & WAN LAN
Can’t be used for long distances (Few KMs).
Cost of data transmission nil.
Computer resources physically connected.
High speed up to 100 Mbps.
Few data transmission errors. WAN
Used Nation wide or Globally.
Costly: Leased Lines, Telephone Lines, Microwave or satellite used.
Physical connection is not necessary.
Less speed of a few Mbps.
More data transmission errors.
Slide 18 : SI Rajesh http://tutor-desirachh.blogspot.com 18 According to type of working/operation, networks may also be classified as:
P2P (Peer to Peer Networks) or End to End Networks.
Client server Networks.
P2P Networks : SI Rajesh http://tutor-desirachh.blogspot.com 19 P2P Networks Every computer works as a client and server itself.
File/Device Sharing is possible.
Each computer is responsible for managing its resources.
Client Server Networks : SI Rajesh http://tutor-desirachh.blogspot.com 20 Client Server Networks Server has special operating system e.g. Windows 2000 adv. Server, Win NT Server, LINUX Server OS. It is powerful computer (Mini or Mainframe Computer).
All files are shared in file server.
For editing/modification files are brought to Client computer.
After modification files again stored in server computer.
Client computer may have any client OS like Window-98-XP-Vista etc.
Slide 21 : SI Rajesh http://tutor-desirachh.blogspot.com 21 THANK YOU