What is NIC (Network Interface Card)?

Functions of Network Interface Card

• Network interface cards are used to convert data into digital signals. 
• In the OSI model, the NIC card uses the physical layer to transmit signals and the network layer to transmit data packets.
• Network interface cards allow both wired and wireless communications. A wired NIC typically uses an Ethernet cable to connect to the network, while a wireless NIC uses radio waves to connect wirelessly.
• NIC is a middleware between the computer/server and the data network. 
• NIC operates at both the physical layer as well as the data link layer of the OSI model. The physical layer is used to transmit signals and the network layer is used to transfer data packets.
• NICs allow communication between computers connected via a local area network (LAN) as well as on a large-scale network via the Internet Protocol (IP).
• The NIC manages network traffic by prioritizing certain types of data or limiting data transmission to prevent congestion on the network.
• Provides network security features such as encryption to protect the network from unauthorized access.

Types of Network Interface Card

1) Internal Network Card

• It provides a stable and reliable network connection, as it is physically integrated into the device. 
• Internal NICs are faster than USB NICs and support more advanced networking protocols and features.
• USB consumes less power than NIC.

Disadvantages of internal NIC :

• Are not flexible. 
• Permanently installed in the device.
• Are not portable. 
• It may not be suitable for devices that need to connect to multiple networks.
• To repair or replace it, the help of a professional has to be taken. 
• USB is more expensive than a NIC or wireless network adapter.

2) External Network Card

Connects to the device via external NIC, USB, or Thunderbolt port. External NICs are commonly found in laptops and mobile devices, providing a flexible and portable solution to network connectivity.

External NICs are either wired or wireless, and they come in various forms, such as USB network adapters, Thunderbolt network adapters, and PC card network adapters. 

They are easy to install and configure.

Benefits of External NIC :

• External NICs can be easily added or removed from devices, making them suitable for use with multiple devices and networks.
• Are easy to install and use.
• Can be easily replaced or upgraded.
• Suitable for mobile devices and laptops.

Disadvantages of External NIC :

• Internal hardware or cables may be required.
• Not as fast or reliable as Internal Nic.
• More power is required.

3) Wireless NIC

Wireless NICs are designed for Wi-Fi connections. It allows us to connect devices without using cables. 

These NICs use antennas to provide wireless reception via radio frequency waves.

Wireless NICs are dynamic and flexible, making them well-suited for portable devices such as laptops, smartphones, and tablets. They provide network connectivity in areas where a physical connection is not available. 

Wireless NICs can transmit data over short to medium distances, and their speed and reliability depend on the quality of the wireless signal.

Example: Intel 3160 Dual-Band Wireless Adapter

4) USB NIC 

USB NIC connects to the device through a USB port. It provides a network connection through a device plugged into a USB port.

USB NICs are easy to install and use, making them a popular choice for those who need to quickly and easily add network connectivity to a device. 

5) Wired or Ethernet NIC  

The Ethernet NIC was developed by Robert Metcalfe in 1980. It is made by Ethernet cable. This type of NIC is most commonly used in LAN, MAN, and WAN networks.

It is widely used in desktop computers, servers, and other devices.

These are more reliable and provide higher-speed network connections than wireless NICs. 

Example: TP-Link TG-3468 Gigabit PCI Express Network Adapter.

6) Fiber Optics 

These are expensive and more complex NICs that are used as high-speed support systems for network traffic handling on server computers.

How does a network interface card work?

It is a physical card that contains a MAC address that helps identify a device on the network.

NIC works at the physical layer and data-link layer. Actually, NIC collects data from the computer and sends it to the transmission channel. It acts as an intermediary between your computer and the data network. It is responsible for exchanging computer data with the network. Any data coming through the network is received by the NIC.

Components of Network Interface Card

A network interface card has the following essential components :

1) Memory: This is one of the most important components of a NIC. It is used to store data during communication.

2) Connectors:  Connectors are used to connect cables to Ethernet ports.

3) Processor: Processor is used to convert the data message into a suitable form of communication.

4) Jumpers: Jumpers are used to manage all the communication functions without the need of any program.

Jumpers are a small devices used to control communication operations without the need for any software. 

It is also used to determine settings for the interrupt request line, I/O address, upper memory block, and type of transceiver.

5) Router: Allows communication between a computer and other devices. Routers are used to provide wireless connectivity.

6) MAC Address: This is known as the “Physical Network Address”, and with the help of this MAC address the NIC card decides where to send the data to the computer system. 

This is a unique address, which is associated with the frame. It gives the computer a unique identity which is also called a physical network address. It is a unique address that exists on the network interface card where Ethernet packets communicate with the computer.

7) Driver: This is essential software that transfers data between the PC's operating system and the network card.

8) LED Indicator: This LED is associated with the connectors, and it helps to inform the user when data is being transferred while connecting the network.

It is a simple LED light that helps to identify the working status of the NIC card.

9) Controller: It is like a mini CPU that monitors the performance of the network adapter.

10) ROM Socket: This socket allows diskless workstations to make connections to the network as well as increase security and reduce hardware component costs.

11) NIC Port:  NIC port is used to connect directly to the Ethernet cable. Generally, NIC has only one port, but these also come in more than one port.

Advantages of Network Interface Card

There are many benefits of NIC which are as follows :

• Are easy to install.
• Multiple users can share large amounts of data.
• There is highly reliable connectivity between nodes.
• Newer network interface cards can achieve data rates up to 2000 Mbps.
• Compared to wireless network cards, NICs provide a secure, faster, and more reliable connection.
• NIC allows us to share bulk data among multiple users.
• It helps us to connect peripheral devices using multiple ports of NIC.
• Communication speed is higher.
• Network interface cards are cheap.

Disadvantages of Network Interface Card

NIC also has some disadvantages which are as follows :

• For wired NICs, a hard-wired connection is required.
• NIC requires proper configuration to work efficiently.
• NIC cards are not secure, so the data inside the NIC is not secure.

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