Internetworking: Networking Blog 2:
Welcome back everyone! I am Shalini Jaiswal your trainer of entire series .
This is my second blog on Networking.
Today we will be starting with Network fundamentals. We will be dealing in basic concepts of networking industry. This blog is not only meant for the people who are going to apply for CCNA certification but for anyone also who is interested in or looking to start a career in networking field.
Let’s start with our first question:-
What is network?
When we talk about network then in our mind usually the first thing which comes are social networks like Facebook, Twitter, Instagram etc. Here we are not going to talk about the social network instead will be learning about computer network.
Let me inform you that network is also foundation or the base on which application like Facebook, Twitter are built on.
Let me share an old story with you all, it’s about older days when Kings exchanged massages form one place to another, they used to pass the massage through a messenger who used to write a host pad and go through all these paved path (roadways) and delivers the massages to particular king.
So if you relate the computer network with the above example, here the road on which messenger travels is called as Network. Massage can be anything such as Data, Excel File, Doc file, Images, Video etc.
If we see in the above image we see that we have firewall , router , laptop, scanner , Windows PC etc.
But inspite of all of the above are running on different operating systems they all can communicate with each other in perfect manner, this is the magic of computer network.
The computer network runs on the global standard called as OSI model that defines to networking framework to implement protocols in layers, with control passed from one layer to the next. A layer serves the layer above it and is served by the layer below it.
How INTERNET works?
CAT 5 ,Rj45 , NIC (network interface card).
If we look above picture this is the very basic network, how computers connected with wires, in this we use CAT 5 cable this has different colour and we have 8 tiny cables these cable are going to be connected with Rj45 cabels that’s something looks like in the picture and the back of that you have port like figure B that is your NIC network interface card.The NIC where RJ 45 connects and using this wire both computer can communicate with each others. This is verybasic form of networking and this is called ETHERNET.
It is used in Local are network (LAN)
The RJ45’s name is derived from the acronym “RJ” which refers to “registered jack” and started out an interconnection standard for telecommunications. It eventually evolved in function, presently used for wired computer networking. The term is sometimes used to refer to the generic 8 position 8 contact (8P8C) connector, but this usage is actually erroneous.
CAT5 refers to the “Category 5” cable, a twisted pair cable used in computer networks. Aside from Ethernet over twisted pair, CAT5 cables are also utilized for video and telephony purposes. The standard provides performance of up to 100 Mbps.
What happens if we have more than two computers?
Let’s take 4 computer connected with switch and printer.
One wayis obviously using cable (Rj45) and network interface card on computer , but better way of connecting is by use of networking device may be a switch or hub.
Switch and hub basically different devices and have totally different functions..
We will learn about the same in next blog.Now from the figure where computer A send DATA to computer B then it send it across to IP address . Now question is what is IP address and how computer recognized in the network .We will learn about IP address in next blog, for now they are just identifiers for the computer.
Another critical reason why people use networking is because of these device.
Let’s assume this is very expensive printer that company has investedin, if networking was not available in the company then the way printer is connected to this device(switch) would have directly connected to any one computer.In this case lets assume that User A wants to print 1 page a day and all other users in the company have similarr equirement of printing one or two pages a day, then in order to satisfy the needs of the users company will have to invest more unnecessarily inproviding separate printer to each userand also the use of printer is minimum.
Better and cost saving way for company is to invest money on infrastructures. Its hould have one good quality printerwhich is to be plugged into network and everybody can give print command to it. It is very efficient way of using the resources and that too within budget.
So this basic requirement of computer networking for any organization.