Networking for All - Technology Simplified.

Routing  

What is Routing? 

Routing is a process of selecting a path in a network over which packet shall be sent to a destination. OR

The term routing refers to a process of taking a packet from one device and sending it through the network to other device.
 

This routing process is done at Layer 3 of OSI layer model i.e. Network layer.

Is really routing required in Networks? 
Routing is analogous to locating a house. We can imagine how important it is for a Courier Service Company, to locate a destination (house) in order to deliver the shipment.
 

To locate a house, the minimum details required are - State, district/city, locality, street address and house number. Once the house is located, the next task is to deliver the shipment.
In the same way, routing is very much required to locate the host in a network and deliver the information.

Likewise some minimum details are required for a Courier Company to deliver the shipment, router also make use of some address (IP Address) to locate a destination host in a network.

Basically Routing involves 2 important processes - one is to locate a host and the other is to find out a best path to reach it.

Routers really don’t care about the hosts. They only care about the network and the best path to reach that network. The logical address of the destination host is used to locate that host in a network. 

Once the destination host is located, the hardware address of the destination host is used to deliver the packet or information.

Here the hardware address is MAC address and logical address is IP address. We will discuss in detail about MAC and IP address in upcoming posts.

Routing also helps in efficient management of network layer and its resources. It also helps in congestion management.  

If network has no router, then it clearly means that you are not routing.
 

Now there might be a question running in your mind. Some of you may relate this to your working environment also.
“I have no router in my network, but still I can send the information from source host to destination host correctly. How it is possible? “

Yes. In your case, the source and destination are in the same network and the primary function of the router is to locate a network first and then follows location of host. If network is already known, then there is no role of a router in delivering the information.

So, Router helps us in sending a data from one network to another network.

By now, I think we have tuned our understanding about function of router and routing process. 

To route a packet, a router must know
1. Destination IP Address.
2. Neighbor router from which it can learn about remote Network.
3. Possible route to all remote networks.
4. The best route to each network.

Router can route the packet only when it knows the information of neighboring connected routers.

How router learns the information of neighboring connected routers? Whether administrator has to do some manual configuration or protocols take care of them? All these things we will discuss in next post. 

Hope you have enjoyed the reading. Your queries and feedback are welcome.

Have a nice time

Networking for All - Beginning with Basics

Introduction

What is Network?
A network is a group of two or more computer systems linked together. In general Networking means connectivity. 

Why Networking?
Computers are interconnected for serving different purposes like data sharing, resource sharing, remote operations, etc.

Data Transmission
To transmit a data from one computer to another computer, we may make use of an external storage device like USB pen drive, DVD/CD-ROM or an external hard disk. This is good when the data transmission is not frequent and not dynamic.  Suppose if the data transmission is frequent, then it is very difficult to rely on these external memory devices.

Is it not great if this data transmission can be done at the click of mouse without any movement of external memory devices?

Yes, With the help of networking it can be done.
Connecting these two computers via switches or hubs or modems will help us in transmitting the data from one computer to another very easily. This is data sharing.

The question that might be running in your mind now is what are these Switches, Hubs and Modems?

Do not worry much about these things right now.Let me explain these things in detail later. 

For time being just understand that these are the devices which helps in connecting one computer to another computer.

Now let us continue our discussion of Data transmission or Data sharing.

Data Sharing
Data will be present in server (Server is a computer with high configuration) and all other computers will access the data from the server, process this data and stores back in the server.

Resource Sharing
Suppose, there are 10 computers in an office and there is only one printer. All these computers are spread over different corners of the office. If employees working on these 10 computers need to access the printer, then they have to connect their computer to the printer via a printer cable. They have to do this every time they need a print. Organizations cannot provide printer for every computer and is not a wise thing to do also. But, when these computers are interconnected and are also connected to a printer, irrespective of the position of the computer, employees can access the printer and take the print of their documents at will.

In this case, printer is a resource and with the help of networking, the printer can be shared among all the users. This is resource sharing. With networking, resources can be shared and used efficiently.

Similarly, High configuration servers are shared by low configuration computers for running some applications. This is also the case of resource sharing. Here CPU, RAM, etc of server are the resources.

To summarize, data transmission, data sharing and resource sharing are important reasons for networking.

What are the applications of Networking?
E- commerce (Online shopping, Online ticket booking, Online banking)
Remote operations (Telnet, Remote login, NMS/EMS )
Powerful social medium – Facebook, Twitter, Videoconferencing, email, etc)
Mobile Communication 

What next ? 
Having understood, the need of networking,  the next question is how to connect these computers or is there any pattern or way to connect them? 

Yes, the way of connection determines the topology of the network.  We will discuss about different types of topology, their features, advantages, limitations applications,etc in detail in the next post..

Have a nice time.