types of computer networks

TYPES OF COMPUTER NETWORKS

Tatheer FatimaBS English (Sec 1-A)

COMPUTER NETWORKS

A network consists of two or more computers that are linked in order to share resources, exchange files, or allow electronic communications.

The computers on a network maybe linked through cables, telephone lines, radiowaves, satellites or infrared light beams

NEEDS OF COMPUTER NETWORK:

File sharing Resource sharing Communication and collaboration Remote access Data protection

TYPES OF NETWORKS:

Networks can be divided on the basis of: Geographical Area Network (LAN,MAN,WAN) Connection method (Wired or Wireless Networks) Functionality (client/server, peer to peer, hybrid networks) Topology (bus, star, ring and mesh) Protocol (TCP/IP, IPX/SPX, AppleTalk)

DEVICES USED TO CONNECT NETWORK

Routers Gateways Repeaters Bridges Hub Modems

GEOGRAPHICAL AREA NETWORK:

Local Area Network: LAN is a group of computers and associated devices that share a common

communications line or wireless link. Typically connected devices share the resources of a single processor or server

within a small geographic area. A local area network may serve as few as two or three users or as many as

thousands of users. Examples include twisted pair


Metropolitan Area Network: MAN is a network that interconnects users with computer

resources in a geographic area or region larger than that covered by even a large LAN but smaller than the area covered by WAN

It is also used to mean the interconnection of several LANs by bridging them with backbone lines.

Examples include twisted pair and fibre-optic cables


Wireless Area Network: WAN is a communications network that makes use of existing

technology to connect local computer networks into a larger working networks that may cover both national and international locations.

Examples include fibre-optics, radiowaves and satellites.

DIFFERENTIATION OF GEOGRAPHICAL AREA

CRITERIA LAN MAN WANOWNERSHIP OF NETWORK

private private or public Private or public

DESIGN AND MAINTAINANCE

Easy Not Easy Not Easy

COST Low High HigherNETWORK SIZE Small Larger LargestSPEED Fastest Slower SlowestTRANSMISSION MEDIA

Twisted Pair Twisted Pair and fibre-optic cables

Fibre-optics , radiowaves and satellite

NUMBER OF COMPUTERS

Smallest Large Largest

CONNECTION METHOD:

On the basis of connection method the network is classified into following 2 classes: Wired transmission networks Wireless transmission networks

WIRED TRANSMISSION:

Wired transmission of networks is a category of networks in which wiring is used as a medium for transmission of data

Wired networks use many types of wires described below:Twisted pair and coaxial cables: These type of wires are made up of copper. Transmit data in the form of electric pulses. Data transformation is not very fast and is also not secure.Fibre-optic cables: These type of wires are made up of plastic and glass. Transmit data in the form of light. Data transformation is very fast and speedy and is a very secure type of transformation.

WIRELESS TRANSMISSION:

In wireless transmission data transmission doesn’t require a specific medium rather air is used as a medium to transmit data.

Different frequency waves are used in wireless transmission networks.

Radiowaves: Transmit data ranging between 3kHz- 1GHzMicrowaves: Transmit data ranging between 3GHz- 300GHzRadiowaves: Transmit data ranging between 300GHz- 400THz

FUNCTIONALITY:

Networks are divided into 3 following categories on the basis of functionality: Client/Server networks Peer to peer networks Hybrid networks

DIFFERENTIATION B/T CLIENT/SERVER AND PEER TO PEER

Client/Server Peer -To-Peer

Server has to control ability while client’s don’t.

All computers have equal ability.

Higher cabling cost Cheaper cabling cost Used in small and large

networks Normally used in small networks

with less than 10 computers Easy to manage Hard to manage Install software only in the

server while the clients share the software

Install software to every computer

One powerful computer acting as server

No server is needed

HYBRID NETWORKS:

Hybrid networks are the networks that are based on both peer-to-peer & client-server relationship.

Hybrid networks incorporate the best features of workgroups in peer-to-peer networks with the performance, security and reliability of server-based networks.

Hybrid networks still provide all of the centralized services of servers, but they also allow users to share and manage their own resources within the workgroup.

Users can assign local access to resources in their computers. Workgroups can manage resources without requiring assistance from network

administrator Users may need to remember multiple passwords. Files saved on the workstation are not backed up.

TOPOLOGY:

Topology defines the arrangement of nodes, cables and connectivity devices that make up the network. There are 2 basic categories of topology: Logical topology: It describes the logical pathway a signal follows as it

passes among the network nodes Physical topology: It describes the actual layout of the network

transmission media i.e. how the transmission media is wired together. Common Physical topologies include:

Bus topology Star topology Ring topology Mesh topology

BUS TOPOLOGY:

Definition All computers and

devices are connected to a central cable.

Advantage Easy to connect a

computer or peripheral to a linear bus Requires less cable length than a star topology.

Disadvantage Entire network

shuts down if there is a break in the main cable. Terminators are required at the both ends of the backbone cable.

Difficult to identify the problem if the entire network shuts down.

STAR TOPOLOGY:

Definition All devices are

connected to a central device called hub.

Advantage Easy to install and

wire.

Disadvantage Requires more

cable length than a linear topology

Security can be implemented in the hub/switch. If the hub or

concentrator fails, nodes attached are disabled.

More expensive than linear bus topologies because of cause of concentrators.

Easy to detect faults and to remove parts.

MESH TOPOLOGY:

Advantage Provide redundant

path between device.

Disadvantage Requires more

cable than other topologies. The network can be

expanded without disruption to current user.

Has complicated implementations.

Definition In the mesh

topology each computer is connected to the others by separate cable.

RING TOPOLOGY:

Definition Cables forms

closed rings or loop, with all computers and devices arranged along ring.

Advantage Data is easily

transferred without a “bottleneck”.

Disadvantage Data packets must

pass through every computer between the sender & receiver which makes it a slow process.

The transmission of data is relatively simple as packets travel in one direction only.

If any of the nodes fail then the ring is broken n data transmission stops.

It is difficult to troubleshoot the ring.

PROTOCOL:

Protocol is a set of rules for the exchange of data between a terminal and a computer or between two computers.

Without protocol computers maybe connected but communication is not possible

Protocol is a sort of precommunication agreement about the form in which a message or data is to be sent and received.

The highlighted protocols include:1. TCP/IP protocol suite2. IPX/SPX protocol suite3. Apple talk

TCP/IP PROTOCOL SUITE

TCP/IP protocol suite was first defined in 1974. IP stands for internet protocol. It is a network layer protocol that is

responsible for delivering packets to network devices. TCP stands for transmission control protocol.it ensures a sent

message is sent without any loss of data or any mix up of the order of the data.

SPX/IPX PROTOCOL:

IPX/SPX is a routable protocol and can be used for small and large networks. It was created by Novell primarily for Novell NetWare networks, but is popular enough that it is used on products that are not from Novell SPX - Sequenced Packet Exchange operates at the transport layer

providing connection oriented communication on top of IPX. IPX - Internetwork Packet Exchange supports the transport and

network layers of the OSI network model. Provides for network addressing and routing. It provides fast, unreliable, communication with network nodes using a connection less datagram service.

APPLE TALK:

AppleTalk was a proprietary suite of networking protocols developed by Apple Inc. for their Macintosh computers.

Apple Computer developed the AppleTalk protocol suite to implement file transfer, printer sharing, and mail service among Apple systems only.

It is secure than other protocols

THANKYOU!

types of computer networks

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