topology in networking-final

8/6/2019 Topology in Networking-final

1/27

Topology In NetworkingTopology In Networking


2/27

Contents

Introduction to Network Topology.

Different types of Network Topology.

Advantages and Disadvantages ofdifferent Network Topologies.

Different device used in establishing the

network. Different standards used for network

topologies.


3/27

What is a Network?

A group of two or more computer systems linkedtogether is a network.

There are many types of computer networks, including:

Local area networks (LANs):-The computers aregeographically close together and connected with cables.

Wide area networks (WANs):-The computers are fartherapart and are connected by telephone lines, radio waves,or some other media.

Metropolitan Area Network (MANs):-Is a large computernetwork that usually spans a city or a large campus. AMAN usually interconnects a number of LAN using ahigh-capacity backbone technology, such as fibre-opticallinks, and provides up-link services to WAN and theInternet.


4/27

In addition to these types, the followingcharacteristics are also used to categorize differenttypes of networks :-

Topology : The geometric arrangement of acomputer system.

Protocol : The protocol defines a common set ofrules and signals that computers on the network useto communicate. One of the most popular protocolsfor LANs is called Ethernet. Another popular LANprotocol for PCs is the IBM token ring network .

Architecture : Networks can be broadly classified aseither a peer-to-peer or client/server architecture.


5/27

LANs

A single geographicallocation, such as

office building, school,etc

Typically High speedand cheaper.

It is establishes byusing different devicesand cables.

LOCALAREA NETWORK (LAN)


6/27

WIDEAREA NETWORK (WAN)

A Wide Area Network (WAN)

is a network system that

covers a large geographical

area such as different cities of

country or different countries of

the world.

The Internet is the worlds

largest network.

WAN, In WAN telephone

lines, satellites, microwave,fiber optic etc. are used as

transmission media.


7/27

Network Topology

Network Topology :- study of Physical (real) and

Logical (virtual) interconnections between

nodes.

Physical :- Actual layout of the computer cables

and other network devices

Logical :- the way in which the network appears

to the devices that use it.


8/27

By graphical mapping of the

connections which includes:-

Physical Connections.

Distance between nodes.

Transmission rates.

Limited number of stations.

Identifying any Network Topology


9/27

Categories of Network Topology

Physical Topology.

Logical Topology.

Hybrid Topology.


10/27

Physical Topology

The mapping of the nodes of a network and thephysical connections between them i.e., the

layout of wiring, cables, locations of nodes,interconnections between the nodes or cablingor wiring system.

Multiple systems connected to shared medium.

Low delay.

Low error rate.

Broadcast/Multicast capability.

Limited geography 1-2 km.

Peer relationship between stations.


11/27

Classification of Physical Topology

It is classified into basically in the five

different types:-

Bus Topology.

Tree Topology.

Mesh Topology. Ring Topology.

Star Topology.


12/27

Bus Topology

In LAN where bus topology is used, each machine

is connected to a single cable.

Uses a trunk or backbone to which all of thecomputers on the network connect.

Systems connect to this backbone using Tconnectors ortaps.


13/27

Tree Topology

The type of network topology in which a central 'root' node isconnected to one or more other nodes that are lower level in

the hierarchy with a point-to-point link between each of thesecond level nodes and top level central 'root' node, while eachsecond level nodes that are connected to the top level central'root' node will also have one or more other nodes.

The signals that are being transmitted by the root node arereceived by all the nodes at the same time. This increases the

efficiency of the over all functioning of the network.


14/27

Mesh Topology

A topology in which thereare at least two nodes withtwo or more paths betweenthem.

Each computer connects toevery other.

A variation hybrid mesh create point to pointconnection between specificnetwork devices.

If n is total no of nodes in

network then No. of links toconnect these nodes in

mesh = N (N-1)/2

Each node should have (N-1)I/O ports as it requireconnection to every anothernode.


15/27

Ring Topology

A topology in which that data travels in circular fashion from

one computer to another on the network. Each node connects to exactly two other nodes, forming a

single continuous pathway for signals through each node.

Each machine or computer has a unique address that is usedfor

identification purposes


16/27

Star Topology

All computers/devicesconnect to a central devicecalled hub or switch.

Each device requires a

single cable. Point-to-Point connection

between the device and hub.

Most widely implemented.

Hub is the single point offailure.

The hub acts as a signalbooster or repeater.

The star topology isconsidered the easiesttopology to design andimplement


17/27

Bus TopologyAdvantages DisadvantagesCheap and easy to implement. Network disruption when

computers are added or

removed.

Require less cable. A break in the cable will

prevent

all systems from accessing

the network.

Does not use any specializednetwork equipment.

Difficult to troubleshoot.

It is easy to handle and

implement.This limits the number of

stations that can be connected.


18/27

Tree TopologyPoint-to-point wiring for

individual segments.In depends length of the network

depends on the type of cable that is

being used.

All the computers have

access to the larger and

their immediate networks .

This network is entirely dependent

on the trunk which is the main

backbone of the network. If that has

to fail then the entire network would

fail.

Best topology for branched

out networks.

Since the Tree Topology network is

big it is difficult to configure and

can get complicated after a certain

point.


19/27

Mesh Topology Security as data travels

along a

dedicated line.

There is mesh of wiring

which

can be difficult to manage. Points to point links make

fault

identification easy.

Installation is complex as

each

node is connected to every

node.

Provides redundant pathsbetween devices.

Requires more cable than theother LAN topologies.


20/27

Ring TopologyCable faults are easily located,

making troubleshooting easier.

Expansion to the network can

cause network disruption.

Ring networks are moderatelyeasy to install.

A single break in the cable candisrupt the entire network.

A central server is not required

for the management of this

topology.

The movement or changes

made to network nodes

affects the performance of theentire network.


21/27

Star TopologyEasily expanded without

disruption to the network.

Requires more cable.

Cable failure affects only a single

user.

A central connecting device

allows for a single point of failure.

Easy to troubleshoot and isolate

problems.

More difficult to troubleshoot

and isolate to implement.


22/27

Logical Topology

The logical topology, in contrast to the "physical", is

the way that the signals act on the network media, or

the way that the data passes through the network

from one device to the next without regard to thephysical interconnection of the devices.

Logical topologies are often closely associated with

Media Access Control (MAC) methods and protocols.

Logical topologies are able to be dynamically

reconfigured by special types of equipment such as

routers and switches.


23/27

Hybrid Topology Hybrid network is the

combination of differenttopologies such asStar, Ring, Mesh, Busetc. For Eg :- if adepartment uses a Busnetwork, seconddepartment uses thering network, thirddepartment uses theMesh network and

fourth department usesthe star network.

All of the abovenetworks of fourdifferent types can beconnected together


24/27

Introduction To Devices


25/27

IEEEand Networking Standards

Institute of Electrical and Electronic Engineers

(IEEE) developed a series of networking

standards Networking technologies developedby manufacturers are Compatible Cabling,

networking devices and protocols are all

interchangeable under the banner of a specific

IEEE.


26/27

802.3 IEEEStandard

Defines characteristics for Ethernet networks:

802.3u for Fast Ethernet.

802.3z for Gigabit Ethernet, referred to as 802.3x.

802.3ac 10gbits/s.

Speed: Original 10Mbps, Fast Ethernet 100Mbps,

Gigabit Ethernet 1000Mbps .

Topology: bus or star.

Media: Coaxial and twisted pair cabling, also fibre optic cable.

Access method: CSMA/CD. ( Carrier Sense Multiple Accesswith Collision Detection) for Ethernet Networks.


27/27

THE END

topology in networking-final

Documents