Network Topology

 

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What is a network topology?

topology is the layout of how a network communicates with diferent devices. Or physical arrangement of nodes(computer) in a network

Types of network topology?

So that's what we re going to discuss in this article.

Now a topology is the layout of how a network communicates with diferent devices.

And there are a couple of different categories of topologies There's wired and wireless.

So we're first going to talk about the most common wired topologies.

And the most common wired topology that's used is the star topology.

Star Topology

In a star topology, all computers are connected to a central wiring

point, such as a hub or a switch.

All data on a star network passes through this central point before continuingto its destination.

• advantage

One of the major

  benefits of this topology is

that if one computer failed or if there was a break in the cable

the other computers would not be affected because each computer has their own cable connection.

However a disadvantage of the star topology is that if

the central hub or switch fails, then all the computers on

that central point would be affected.

This is called a single point of failure.

If this happens the entire network goes down.

Another type of topology is called ring.

The ring topology is a type of network configuration where each computer is connected to each other

in the shape of a closed loop or ring.

So every computer on this ring has exactly two neighbors for communication purposes. purposes.

Each data packet is sent around the ring until it reaches its final destination.

• advantage

This kind of topology is rarely used today.

The advantage of a ring topology is that they are easy to install and easy to

troubleshoot.

• disadvantage

However, the disadvantage would be, that if just one of

these computers goes down or if there was a single

break in the cable, then all data flow would be disrupted.

Bus topology

And the next on is the bus topology

The bus topology is very old technology and like the ring topology, it not used today that much.

This is the kind of network setup where each of the computers and network devices,

are connected to a single cable or backbone.

and this backbone is a coaxial cable.

The computers connect to this cable using special

connectors called BNC, which are also known as T connectors

.

One of the advantages of the bus topology is that it is also fairly cheap and easy to implement.

• disadvantage

However, a disadvantage of the bus topology is that it

requires that the cable is terminated at both ends using terminators.

In order for this setup to remain operational, there must not be any open connections,

including the ends that attach to the computers.

So if a computer is removed or if the terminators

are loose or missing, then the cable would be

open and data would bounce back.

This bounce is known as signal reflection, and if this happens data

flow would be disrupted.

There is also the mesh topology.

In a mesh topology, each computer on the network is connected

to every other computer on the network.

So by having so many connections it handles failure very well.

In this illustration there are 4 computers

with 3 connections on each computer, which makes

a total of 12 connections for this network.

The advantage of a mesh topology is that it creates a high redundancy level.

Because if one or more connections fail, the computers would

still be able to communicate with each other.

But because of the amount of cabling and network cards that have

to be used, mesh topologies can be expensive, so

they are rarely used on local area networks or LANs.

They are mainly used on wide area networks, like the internet.

In fact, the internet is a good example of a mesh topology.

Because the internet is made up of numerous routers, all over the world that are

Connected to each other to route data to their intended desintation.

So even if a few routers go down, the data will get rerouted using a different path to ultimately reach their destination.

So the internet is very redundant because it s using a mesh topology.

So now we re going to talk about wireless topologies.

So let s start with infrastructure wireless topology.

This topology uses a combination of wired and wireless devices.

This is very similar to a star topology, where you have wired devices, such as these

computers here, physically connected to a switch. And you also have a wireless access

point that's also connected by a cable to same switch.

The wireless access point is here so that wireless devices, such as laptops, tablets,

cell phones, etc, can connect wirelessly to the network.

So the wireless access point acts like a bridge between the wireless network and the wired

network.

Now the infrastructre topology is not limited to a single wireless access point..in fact

you can have multiple wireless access points if you want .it just depends on the needs

of the network.

The next wireless topology is Ad hoc.

Ad hoc is a very simple wireless topgology.

It s simple because it doesn t rely on any infrascture, such as cables, routers, servers,

or wireless access points.

All the devices in an ad hoc network, wirelessly connect to other devices in a simple peer

to peer network.

They directly connect to each other without using a centralized device, such as a wifi

router or access point.

And because they directly access each other without a server or router in between, each

device is responsible for its own security and permissions.

Ad hocs are useful for setting up a quick wireless network on the fly, where devices

can share data without the need of an existing wireless network.

And the last wireless topology is called a wireless mesh.

Wireless mesh topologies are similiar to wired mesh topologies, where devices are interconnected

with each other, but with the exception that they are wirelessly interconnected.

So for example, let's say you wanted to deploy multiple wireless access points all throughout

a building so that wireless devices that are in different areas are able to access the

internet.

So normally you would have a modem that brings in the internet to the building, and then

you would have a switch that's connected to the modem.

And then you would connect each wireless access point with a cable to the switch.

So by doing it this way, this requires extra cabling and it would also require extra time

running the cables through the building.

So this is more expensive and more time consuming.

Now a wireless mesh topology would be similiar to this setup, but without the need of these

extra cables.

In a wireless mesh, each wireless access point with talk to other wireless access points

to create a seamless internet connection for wireless devices to connect to. So if this

laptop over here wanted to access the internet, it would connect to the nearest wireless access

point and then this access point will would relay the connection to the next access point

and then the next one and eventually find its way back to the modem.

So no matter which access point that you re connected to, you will have internet access

because all the access points are in constant communication with each other and the modem.

And even if one or more access points were to fail, it wouldn t matter, because the other

access points will reroute the data.

So a wireless mesh topology is very redundant...because the internet connection is spread out over

many wireless access points.

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Ethernet

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