Arranging the nodes or the networking devices in a geometrical way is known as Network Topology.
A network is consisting of several communication devices like mobile phones, computers, ATM machines, etc.
Which are connected with each other through a link.
A link is a path to communicate between two or more devices (communication devices) in a network. With the help of Network Topology, the communication process can be done.
In other words, we can say “the geometrical representation of links and nodes is called network topology.“
Nowadays everyone using the network for communication purposes. It may be a wired or wireless network.
So, in this article, we see network topology and the types of network topology.
1) Network Topology
Categories of network topology
I. Physical Topologies
II. Logical Topologies
I. Physical Topology is the physical part of a network system like wires, hubs, nodes, modem, router, etc. Also, we can say all the visible parts of a network system belongs to physical topology.
II. In Logical Topology, how data will pass from one device to other devices through the network will determine. For example, a twisted pair of Ethernets. It is a bus logical topology.
2.1) Wired Links
In this type of link, we use Wires to make a path of communication to other devices like an ethernet cable, optic fibres, polyvinyl chloride wire (p. v. c), etc.
2.2) Wireless Links
In this type of link, all the wireless devices are used like sensors, wi-fi, wireless phone, Tv remote, etc.
3) Devices which are used in networking
Hub is known as a connectivity device where all the system is connected to share the data.
This device sends the data packets to all systems of that network without any filtration of data.
Nowadays all the computer systems are connecting with a centralized hub through a wire to share the data.
The router is also a device which accepts the requested data of the user via modem, that the router deciphers the data and send it to users’ computer. It also obeys TCP/IP Protocol.
This is also a connectivity device. Also, we can say it is the smart version of a Hub. It receives data packets from one point and then sends it to several points of the network.
also, Know the details about the networking devices.
4) Types of Network Topology
So, there are six network topologies.
4.1) Bus Topology
In this network topology, all the devices are connected with a shared cable or bus with tabs and drop lines to send and receive the data.
Taps are the connectors and drop lines are the cables that connect the device to the bus.
If a device sends the data frame (packed IP packets in the data link layer) to another device. Then, all the devices which are connected to the shared cable will get the frame.
In other words, we can say that other devices can access the data packets or frames which are sent by any of the devices of this topology.
But the target device only accepts the frame by checking the MAC address of the received frame and others reject the frame.
|Easy to send data frames.||Not easy to send and receive data frames at a time.|
|Also, easy to install.||It depends upon the bus because if the bus will fail then the network also fails.|
|It is easy to understand.||If the number of devices increases then it will slower the network.|
|Cabling cost is low. Because a single bus can connect with all the devices.||Used for small network only.|
|Also, easy to connect a device with this network.|
4.2) Star Topology
In this network topology, all the devices are connected with a centralized hub or switch with point-to-point communication links.
So, here point-to-point connection means there are dedicated communication wires between the device and hub or switch. So, any device can’t access the data of other devices directly.
Also in this topology to share the data, a device needs to send the data frame to the hub first. Then the hub will broadcast the frame to all devices in the network.
So, broadcasting increases the unnecessary data traffic in the network.
Therefore, to overcome this traffic problem, we use the switch as a central device. In other words, every device has its own MAC address. The switch has the capability to store the MAC address of individual connected devices and then send the frame with the MAC address to individuals.
|Easy maintenance.||Large cabling required.|
|It is easy to identify the failure in the network. Because all the device is connected with a single connection.||If the centralised hub will stop then the whole network also stops.|
|Data transfer rate is high.|
|Also, Easy to connect and remove with the network.|
4.3) Ring Topology
Each device is connected with other adjacent devices and then forms a ring to communicate with each other.
When any device sends data it will move in a circular direction in the network to reach the target destination.
And then the data frame has to pass from all the devices which will come in between the sender device and receiver device in this ring topology.
|Easy to maintain.||Data frame transfer is slow.|
|Data transfer is high.||If one device gets corrupt then the entire network will terminate or stop.|
|No collision of data.||Data frame has to pass from all the devices which are coming in between the sender and receiver device.|
|Ring topology is cost-effective (low cost to install).|
4.4) Mesh Topology
In this network topology, every device is connected with each other with point-to-point connections or links. Here every device can send and receive data frames with other devices in the network.
In other words, if there are 4 devices(n)
Then number of connections=n(n-1)
=12 (simplex links)
Simplex links can transfer the data in one direction only.
In other words it uses one link to send data and other link to receive the data.
Then, to overcome this one direction data transfer process in mesh topology we use Duplex links.
Duplex links are capable of sending and receiving the data in both directions.
Therefore we use one duplex link here at the place of two simplex links. Then the number of links in the network will be n(n-1)/2
So, in this mesh topology, the data frames can be sent directly to the target devices through the individual links. Also, other devices can’t access the data frame.
A Regional telephone office use mesh topology to connect with other telephone offices.
|High security.||Implementation cost is high.|
|Easy to find out the problem in the network.||Large cabling required.|
|All the connections are carrying its own data.||Difficult to maintain the network.|
4.5) Tree Topology
Simply we can describe tree topology as it is the combination of several star topologies.
In other words, in a star topology, there is a centralized hub and all the devices are connected to it.
So, in tree topology all the hubs of different star topologies are connected with a main or we can say parent hub to communicate with each other.
Here we can see all the devices are connected with the hub and then hubs are connected with the server or we can say the main computer.
|Centralised monitoring system.||Difficult to reconfigure.|
|Point-to-point connection.||Cabling cost is high.|
|If one device of the network will damage then it will not lead the whole system error.||If the main hub fails then the entire network will fail.|
|Maintainance of the network is easy.|
|Easy to identify the fault in the network.|
|Easy to connect with the network.|
4.6) Hybrid Topology
A hybrid topology is a combination of various topologies.
In other words, this topology uses all 5 network topologies to form a better network. So, here we can see the combination of ring topology and star topology.
For Example, An institute is using a network where they used ring topology for its library system and star topology for their lab. Then they connect all the topologies to a bus topology to make an easy and suitable network for their institute.
|It can be modified.||It is not cost-effective.|
|Easy to add another network.||This is not easy to understand.|
|It is flexible.|
The basic example of network topology is the local area network(LAN). We use Bus, Tree, Mesh and Star topology to connect the devices of LAN.
The geometrical representation of links and nodes is called as network topology. It is of 6 types- Bus, Mesh, Star, Tree, Ring and Hybrid Topology.
There are 6 types of topology.
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