INTRODUCTIONABOUT NETWORKCOMPONENTSPHYSICAL TOPOLOGY AND ITS TYPESTYPES OF NETWORKLAYERS IN OSI MODELTCP/IP PROTOCOL SUITECONNECTING DEVICESAPPLICATIONSCONCLUSIONREFERENCES
A network is a combination of hardware and softwarethat sends data from one location to another.Two or more computers that are interconnected sothey can exchange data, information & resources.A networked connection allows computer tocommunicate with other devices.
A network is a set of devices (often referred to asnodes) connected by communication links.A node can be a computer, printer, or any otherdevice capable of sending and/or receiving datagenerated by other nodes on the network.
every device has adedicated point-to-pointlink to every other device.Need n(n - 1) physicallinks.Need n(n -1) /2 physicallinks.
Better privacy and securityMore robust•Installation is difficult•Reconfiguration is difficult
Each device needs only one link and one I/O port.Installation and reconfiguration is easyIf the central hub fails, the whole network fails.
Installation is easyRequire less cable and I/O port•If the backbone fails, the whole network fails.•Reconfiguration is difficult.
Fault identification is easyEvery node is given equal access to the token•Adding or removing nodes disturb the network•Failure of node in a ring can affect the entire network.
A local area network (LAN) is usually privately ownedand links the devices in a single office, building, orcampus.Speeds are normally 100 or 1000 Mbps.LAN topologies are bus, ring, and star.LAN size is limited to a few kilometers.
A wide area network (WAN) provides long-distancetransmission of data, image, audio, and videoinformation over large geographic areas that maycomprise a country, a continent, or even the wholeworld.A WAN can be as dial-up line that connects a homecomputer to the Internet.
MAN means metropolitan area network.A metropolitan area network (MAN) is a networkwith a size between a LAN and a WAN.It normally covers the area inside a town or a city.
Open Systems InterconnectionStandard Model for Data CommunicationsSpecified by International Standards Organization(ISO)Adopted by CCITT/ITUOfficial Model Explained in X.200 Series
The physical layer coordinates the functions requiredto carry a bit stream over a physical medium.The physical layer is responsible for movements ofindividual bits from one hop (node) to the next.
Physical characteristics of interfaces and mediumRepresentation of bitsData rateSynchronization of bitsLine configurationPhysical topologyTransmission modeBegin EndDataLink Layer
Data Link layer adds header and trailer to the datareceived from the higher layer.It transports the data as Frame.This layer is responsible for the delivery of framesfrom node to node.
Transport layer adds header to the data received fromthe higher layer.It transports the data as segments.This layer is responsible for the delivery of segmentsfrom one process to another process.
The session layer is responsible for dialog control andsynchronization.Session layer is also responsible for terminating theconnection.CharacteristicsDialog controlSynchronization
The presentation layer is responsible for translation,encryption and compression.Presentation layer defines the format in which thedata is to be exchanged between the twocommunicating entities.CharacteristicsTranslationEncryptionCompression
The application layer is responsible for providing servicesto the user.Application layer interacts with application programs andis the highest level of OSI model.Examples of application layer are applications such as filetransfer, electronic mail, remote login etc.CharacteristicsNetwork virtual terminalFile transfer, access, and managementMail servicesDirectory services
Data sharingInstant And Multiple AccessesVideo ConferencingInternet ServiceBroad CastingRemote Access And LoginSaves Cost
The development of the personal computer broughtabout tremendous changes for business, industry,science, and education.A similar revolution is occurring in datacommunications and networking.Technological advances are making it possible forcommunications links to carry more and fastersignals. As a result, services are evolving to allow useof this expanded capacity.
Data communication and networking by Behrouz A.ForouzanData and computer communication by WilliamStallingsComputer Networks by Larry L. Peterson and Bruce S.DavieComputer networks by Andrew S. TanenbaumComputer Networking by James F. Kuruse, keith W.Ross.