Understanding Network Interface Card (NIC)

Understanding Network Interface Card

A network interface card (NIC) is the hardware in your computer that helps your system connect with the Internet and other forms of network. This hardware unit sits in a specific slot and provides a communication bridge between your device and the web. There are several synonyms for network interface cards. For example, some people call it a network adapter, a Local Area Network (LAN) card, or a physical network card. With the network interface card, you are getting the working of almost all standard buses for data transfer between your computer and other devices.

Buses and connectors work as an intermediary for the conversion of communication between many devices. They can convert serial communication to parallel transmission. In addition to this, with the use of NIC, you get to format the data based on the architecture of the network. With the help of this article, we are going to shed some light on one of the essential parts of the computer network, which is the NIC. In this article, we are going to define what NIC is, its usage, and the different types of NIC. In addition, we will also discuss the benefits of using NIC in your system.

What is a Network Interface Card?

There are multiple ways by which you can connect with another computer or a network. There still has to be a NIC present in both the computers for the communication to take place. NIC’s primary purpose is to prepare the data so it can be sent over the chosen network medium. The preparation of data depends on the medium by which the communication is going to take place. Most of the networks that are currently working all over the globe are using an Ethernet connection.

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Even though it was developed in the 1960s, Ethernet is still relevant to this day. It takes the use of Carrier Sense Multiple Access/ Collision Detection. In this, each computer takes the responsibility of monitoring the network to see if some other system is sending the data over the network at the same time. If two computers are identified sending the data at the same time on the same Ethernet network, there can be collisions taking place, but they can be inverted with the use of CSMA/CD. The second computer that is sending the data will wait for a random amount of time interval to once again send the data over the Ethernet.

As we said earlier, NIC is a physical car, or you can say a hardware chip that sits inside your CPU cabinet. It has its own MAC address, which helps in finding the device on the network. The NIC works on the physical and data-link layer of the OSI model. It collects the data from the computer and then sends it to the transmission channel. As a result, it works as a communication bridge between your computer and the network. Besides, any other data that comes from the web to your computer will be transferred via the NIC of your computer.

How Does NIC Transfers Data

When a user needs to send the data over the network, the network protocol will first transfer the packet to the buffer located in the NIC card. After that, the NIC card will calculate the Cyclic Redundancy Code (CRC) that is present in the numeric form. This CRC comes from the destination MAC address that can be found in the frame header. This CRC also works as a checksum that aims to detect errors. In the end, NIC will send out the frames onto the network medium in the form of bit signals.

On the other hand, when it comes to receiving the data, the transferred bit will travel along with the medium, and NIC will receive them. After that, the received bits will be converted into a frame. The CRC is again calculated here and compared with the CRC that is present in the frame trailer. If these two don’t match, it means the frame has some loss, and it is damaged somehow. In that case, NIC will discard the frame. The NIC will check the destination MAC address when the CRCs are matched. After the confirmation of MAC address. The header present in the frame and its trailer will be removed. The data packet will come out from the frame. The data packet will then again be sent to the network protocol so that it can be processed further and received correctly by the system.

Components of NIC

NIC has its own set of hardware and features that make it unique from other hardware cards that you install in the system. Given below, we have briefly described each of them.

Speed: Every NIC has its own speed that is defined in Mbps. This can be used to measure the performance of the card when you install it on the computer. If you connect the NIC with a lower bandwidth network, your computer will surely slow down. For an average Ethernet NIC, you will be getting 10Mbps, 100Mbps, 1000Mbps, and 1Gbps speed limits, depending on user needs. Keep in mind that when you go for a higher speed, you will also have to spend more money to purchase the card.

Driver: This is required software that needs to be present in your computer to run the NIC card when it is installed on your computer. When you install the NIC on your motherboard, the software will be automatically downloaded the next time you start the operating system. Also, to get the best performance from your card, you need to keep on updating the software regularly.

MAC address: this is a unique address for your NIC, and it is not changeable. MAC address is also known as the physical address. The primary function of the MAC address is to define the system in the network and deal with the Ethernet packets to and from the computer.

The connectivity LED: Each NIC you will find in the market has an LED indicator soldered to the connector. This is done to help you notice that the network is connected and data is also being transmitted. When the LED is blinking, the NIC is working fine; if it’s not, you need to check what the issue is.

Router: Routers are sometimes needed to make the connection accept the new changes in the network. The NIC makes the connection with the router, and then the router connects it to the Internet.

Different Types of Network Interface Cards

There are two different types of network interface cards. They differ from each other based on the interface of the host, transmission speed, and the application fields. Given below, we have defined each of its types for your better understanding.

Network Connection Based Classifications

Depending on how a network card is connected to the network, it could be a wired NIC or wireless NIC. A wired connection NIC will have a node onto the web, and it will be connected via Ethernet cable and fiber optic cable. On the other hand, for wireless NIC, you get a small antenna that uses a radio wave to communicate with the access point. So it can be involved in the wireless network as well.

Bus Interface Based Classifications

Industry Standard Architecture (ISA) network card: This bus system was developed in 1981, and it became the standard bus architecture for IBM compatibles. But, it has a low card speed and can go up to 9Mbps. Now it is no longer used, and if you want to implement it in your vintage computer, it is going to take some time to find the working one.

Peripheral Component Interconnect (PCI): The PCI bus came into existence in 1990. It was invented to replace the previously working ISA bus standard. In addition to this, it fixed the width of 32-bit and 64-bit transmission of data. These NIC cards were first used in servers, and then many people started using them in their personal systems as well. If we look at the systems of modern-day most of them don’t come with expansion cards. Because they already have the NIC integrated into the motherboard. Thus, you can say with the advancement, even the PCI cards were replaced by the new generation of PCI-X or USB interface.

Peripheral Component Interconnect Express (PCIe): This new bus standard has now become the global standard and is now popular on both computer and server motherboards. There are a total of five different versions of PCIe cards, and each version comes with the support of five types of lanes that work on other network speeds.

Universal Serial Bus (USB): These are external buses, and you need to connect them with the computer. A USB bus is available in three different data rates, and it can work together on several devices. Moreover, when we look at the wireless network card, we can see it is designed to work with the Wi-Fi connection as well.

Differences Based on the Field of Application

NIC Cards for Computers: Most of the computers that are now being sold come with a built-in NIC card. That is present in the motherboard, so you don’t need to buy a separate LAN card. The standard form of these NIC cards can range from 10Mbps speed to 100Mbps, and it can go up to 1Gbps. These are used in personal computing and help in the communication of one PC with the other.

Server network card: The primary use of having a server network card is to manage and handle network traffic. In comparison to other forms of network cards, a server adapter will require a faster data transmission speed, such as 10G, 25G, 40G, and 100G. On the other hand, server adapters have a very low occupancy rate because it is the unique network controller that takes up the many heavy lifting tasks from the CPU and completes it.

Benefits of Using Network Interface Cards

So now you know a lot about NIC and how many different options you can choose from. Let’s look at some of the benefits you get with the use of NIC and how it helps you in networking as well.

1. Speed

With the NIC, you will indeed have a much better network speed than the usual connection. For example, when you are using the 1 Gigabit NIC, you will have a much more constant high-speed Internet connection than you would have if you are connected to a wireless network.

2. Inexpensive

NIC cards are not expensive, you can get them as low as $10, so it becomes easier for you to upgrade them anytime you like. Moreover, most modern motherboards have inbuilt NIC so they can be easily connected to the network without having to buy any extra hardware.

3. Easy to Troubleshoot

They make it easier for IT professionals and individuals to troubleshoot their network problems. This is because most of the NICs come with an indicator light that will blink or change color based on the problem it is facing. If the card is flashing green light, it means it has good communication. If you see a red or amber color light, it means your card is having some problems while communicating with the network.


So this is what a Network Interface Card is all about. It might seem like a small hardware product for your computer. But it is the one that makes your computer connect with the Internet and with other networks as well. In the end, it depends on you whether you need a special NIC card or not. For most people having an external NIC card is not a requirement, but if you are facing issues with the built-in one then going with the external or even a PCI-e NIC card can resolve the problem.


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