Network topologies for management
-
Upload
saugata-palit -
Category
Technology
-
view
382 -
download
2
description
Transcript of Network topologies for management
NETWORK TOPOLOGIES
There are three basic configurations used to connect computers they are the
Bus Ring Star
By:Saugata Palit
NETWORKING & TOPOLOGIES
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Different Types of Hubs Technically speaking, three different
types of hubs exist PassiveActive
Intelligent
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
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
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
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).
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.
THANK YOU