24
NETWORK TOPOLOGIES There are three basic configurations used to connect computers they are the Bus Ring Star

Network topologies for management

Embed Size (px)

DESCRIPTION

 

Citation preview

Page 1: Network topologies for management

NETWORK TOPOLOGIES

There are three basic configurations used to connect computers they are the

Bus Ring Star

Page 2: Network topologies for management

By:Saugata Palit

NETWORKING & TOPOLOGIES

Page 3: Network topologies for management

Bus topology

This type of network was widely used in the 1980’s In this configuration every computer (node) shares

the networks total bus capacities. In this configuration adding more computers will

reduce the access speed on the network. Each computer communicates to other computers on

the network independently this is referred to as PEER-TO-PEER networking

Page 4: Network topologies for management

How a Bus Peer to Peer Network Works All computers on a network have a

distinct address just like your house does

a message would be send from one computer with the address of another computer attached to the message

The message is broadcasted to all the computers on the network until the addressed PC accepts the message

Page 5: Network topologies for management

Problems One of the main problems with this type

of network is that it is not very fault tolerant, a break or defect in the bus would affect the whole network

Page 6: Network topologies for management

Ring Topology In Ring topology each node is connected to the

two nearest nodes so the entire network forms a circle

Data only travels in one direction on a Ring network

Page 7: Network topologies for management

How this Topology works a node has information to send to another

computer on the network so it sends the information out on the network to the PC it is connected to, if the information is for this PC (the recipients NIC address is attached to the message, which is like putting an address on an envelope) then the PC accepts the data

otherwise it passes the information on to the next PC by repeating the data back out on the line

This method of repeating the data helps keep the integrity of the data readable by other computers

Page 8: Network topologies for management

How it Works As it is better to have computers take

turns using the connecting Data cable, Ring topologies incorporated a system called Token passing

In this topology, to transmit on the wire your computer must have control of the token or wait for the token to be free

Larger Token Ring networks use multiple tokens

Page 9: Network topologies for management

Problems and Solutions The drawback to this type of topology is that a single

malfunctioning workstation can disable the whole network

To make sure all the information is sent the receiving PC sends the token back to the sending PC after it has received all the data

If the sending PC is finished sending it passes the token to the next PC

This type of network was also widely used in the 1980’s

This type of network used Thinnet cable joining nodes. In the mid 1980’s Thinnet cable was replaced by

Category 3 Ethernet cable capable of handling up to 10Mbps

Page 10: Network topologies for management

Star topology

In a Star topology every node is connected through a central device such as a Hub, Switch or Router

Compared to a Ring or Bus topology a Star topology requires that more thought be put into its setup

HUB

Page 11: Network topologies for management

The Good and Bad of a Star Network The upside of a star network is that if

any one cable fails then only the node connected on that cable would be affected

Another positive point to this type of network is that it is very simple to join two star networks together by connecting their central devices to each other

Page 12: Network topologies for management

The Good and Bad of a Star Network As each computer is connected to a

central device (Hub) the location of the Hub must be made as central as possible, so as to reduce cable lengths

The drawback to this type of topology is if a central device was to fail then all computers connected to that device would not be able to see the network

Page 13: Network topologies for management

What is a Hub? A hub is usually a small rectangular box,

often made of plastic, which receives its power from an ordinary wall outlet

A hub joins multiple computers (or other network devices) together to form a single network segment

On this network segment, all computers can communicate directly with each other

Page 14: Network topologies for management

What is a Hub? Ethernet hubs are by far the most

common type, but hubs for other types of networks such as USB also exist

A hub includes a series of ports that each accepts a network cable

Small hubs can network four computers together

They contain four or sometimes five ports

Page 15: Network topologies for management

What is a Hub? Many times the fifth port is reserved for

"uplink" which is the connecting of one hub to another hub or similar device (joining two segments together).

Larger hubs contain eight, 12, 16, and even 24 ports

Page 16: Network topologies for management

Key Features of Hubs

Hubs classify as Layer 1 devices in the OSI model

OSI stands for :The Open Systems Interconnection Basic

Reference Model At the physical layer, hubs can support little

in the way of sophisticated networking Hubs do not read any of the data passing

through them and are not aware of their source or destination

Page 17: Network topologies for management

Key Features of Hubs

Essentially, a hub simply receives incoming packets, possibly amplifies the electrical signal, and broadcasts these packets out to all devices on the network - including the one that originally sent the packet!

a packet is a formatted block of data carried by a computer network

Page 18: Network topologies for management

Different Types of Hubs Technically speaking, three different

types of hubs exist PassiveActive

Intelligent

Page 19: Network topologies for management

Passive hubs Passive hubs do not amplify the electrical

signal of incoming packets before broadcasting them out to the network

Active hubs

amplify the electrical signal of incoming packets back to their original level before broadcasting them back out on the network

Page 20: Network topologies for management

What is a Network Switch? A network switch is a small hardware

device that joins multiple computers together within one local area network (LAN)

Technically, network switches operate at layer two (Data Link Layer) of the OSI model

Page 21: Network topologies for management

What is a Router? Routers are physical devices that join

multiple wired or wireless networks together

Technically, a wired or wireless router is a Layer 3 gateway, meaning that the wired/wireless router connects networks together

A Gateway is a device that acts like a security guard and only allows data in or out if it has the right network headers

Page 22: Network topologies for management

Routers Home “networkers” often use an Internet

Protocol (IP) wired or wireless router IP is the most common OSI network layer

protocol Protocols are the rules governing the

transfer of data information, it can also be compared to how humans use languages (to get your point across you must talk in the same language as the person you are speaking to).

Page 23: Network topologies for management

Routers An IP router such as a DSL or cable

modem are broadband routers and joins the home's local area network (LAN) to the wide-area network (WAN) of the Internet

A Broadband Router is a device that allows multiple PC’s to access the Internet using only one address.

Page 24: Network topologies for management

THANK YOU