Networking Basics Part 1 - Network hardware devices
In this series, we will start the basic computer networking and work towards building a viable network. Introduced some different components of the network and their performance.
You have seen many articles that have the least experience to target administrators. But here will be the most basic part of the network's launch. In this first article, we will discuss many different network devices and what they can do.
The first component to be addressed between network hardware devices is the network adapter. This device is also known by many different names like Network Card, Network Interface Card, NIC. These are common conditions for all hardware devices. The task of a network card is to physically connect the computer so that it can participate in communication on the network.
When talking about a network card, you first need to know that it must be connected correctly to the network medium. Network medium is the type of cable used on the network. Wireless network is another area and a separate article will be discussed in more detail.
Comparing network cards to network media is a real problem, as they require a large amount of mandatory standards of competition. For example, before creating a network and before you start buying a network card or cable, you must decide whether to use Ethernet, Coxel Ethernet, Token Ring, Arcnet or other network standard. Each network standard has its own length and flaws. It is very important to find out who works best for your organization.
Most of the network technologies mentioned above are disappearing rapidly. Now, the only wired network used in small and medium businesses is Ethernet. You can see the example of ethernet network card in the example in Figure A below.
Modern Ethernet networks use all 8 wire twisted pair cables. These wires are arranged in a special order and the RJ-45 connector is connected to the cable end. The RJ-45 cable looks like a connector at the end of the phone's cord, but it looks bigger. The phone uses the Cordr-11 connector compared to the RJ-45 connector used in ethernet cables. You can see the example of ethernet cable with rj-45 connector in Figure B.
Hub and Switch
As you have seen above, the computer uses a network card to send and retrieve data. Data is transmitted on ethernet cable. However, you cannot usually run an Ethernet cable between two PCs to call it a network.
With today's high-speed Internet access, you may hear the word "broadband" over and over again. Broadband is a type of network in which data is sent and received on the same wire, while Ethernet uses baseband communication. The baseband uses private wires to send and receive data. This means that if the computer is sending data to a particular wire within the Ethernet cable, the computer receiving the data needs another wire to redirect it to its receiving port.
You can network two computers in this way, commonly known as crossover cables. Crossover cable is the only network cable in which wires are sent and received at one end so that the computer can be connected directly to each other.
The limited problem with using crossover network cables is that you cannot add or remove a computer except two already connected. So, better than crossover cable, almost every network uses regular Ethernet cables that do not send wires to the end of the connector and receive.
Of course, to make communication a success, it sometimes has to be reversed to send and receive. This is the job of a hub or switch. The hubs are getting old, but we should still talk about them. Because understanding the hub when it comes to switches makes it much easier for you.
There are many centers, but usually the hub is the box of RJ-45 ports. Each computer on the network will connect to the hub through the Ethernet cable. You can see the shape hub shown in Figure C.
The hub has two different missions. The first task is to provide the central point of connection for all computers on the network. Each computer is plugged into the hub. Multi-port hubs can be chained together if required to accommodate more computers.
The job of another hub is to arrange ports in such a way that if one computer transmits data, the data must be sent to the receiving wire of another computer.
You may be wondering how data can reach the right destination if more than two computer hubs are connected?? This secret is in the network card.
Each Ethernet card is given a unique physical MAC (Media Access Control) address. When the computer on the Ethernet network transmits data to a network with a pc connected to the hub, the data is actually sent to every network machine. All computers receive data, and then compare the target address to its physical MAC address. If it matches, the computer will know that it is a receiver of data, or it will ignore the data.
As you can see, when the computer is connected through the hub, all packets are sent to all computers in the network. The problem is that any computer can send information at any time. Have you ever seen a meeting in which everyone is talking at the same time? This is the problem of a network of this kind.
When the computer needs to transmit the data, it checks if the other computer is sending information at the same time. If the line is free, it transmits the required information. If the other host is already on the line, packets of data transferred to the wire collide and perish (this is why this type of network is sometimes called pulse domain. Then both computers will have to wait a while and try to rebroadcast their destroyed packets.
Switch (you can see in Figure D), performs all the functions like the hub. The only difference is that when one PC on a network needs to communicate with another computer, the switch uses a set of internal logic channels to establish a different logical path between the two computers. This means that both computers have the absolute freedom to communicate with each other without worrying about conflicts.
Switches greatly improve network efficiency. Because they remove conflicts and there is much, they can establish parallel communication routes. For example, when a computer A communicates with computer B, there is no reason to not communicate with computer C at once. In the collision domain, parallel communication types are not possible because they will lead to conflict.
In this article, we discussed some basic elements of creating a simple network. In the second part, we will continue to consider the basic networking hardware. Please continue to look in the following section.
Networking Basics Part 2 - What Is Router??