Network interface controller (NIC)
A Network Interface Controller (NIC) is a crucial component that enables a computer to connect to a network, facilitating communication with other computers. NICs can come in various forms, such as cards or adapters, and can support both wired and wireless connections. Traditionally, NICs were installed as separate expansion cards, but modern computers often have them integrated directly into the motherboard. This evolution coincided with the rise of computer networking in the 1980s and the widespread availability of the Internet.
With advancements in wireless technology, many NICs have transitioned to wireless formats, allowing for greater flexibility and mobility in network connections. Each NIC has a unique Media Access Control (MAC) address, which helps devices communicate securely and manage network access. Data is transmitted in packets, which the NIC formats and directs, ensuring proper delivery and reception. Overall, NICs play a vital role in the transmission of data across networks, supporting both local area networks (LANs) and Internet connectivity, while also enabling essential security measures within network environments.
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Network interface controller (NIC)
A network interface controller (NIC) is a component installed in a computer that allows it to connect to a network of computers. A network interface can be a card, an adapter, or another type of device. Most interface controllers used in the twenty-first century allow computers to connect to a network wirelessly, but there are controllers that require a wired connection. Originally, most computers used a separate interface controller installed in one of the computer's ports; however, it has become more common for an interface device to be installed directly on the computer's motherboard.
Background
Soon after personal computers began to grow in availability and popularity in the 1970s, it became necessary to find a way for them to communicate with one another. The first NICs were added to computers after they were manufactured. These were called expansion cards, and they were installed by connecting them to the computer's motherboard through a special connection port. A motherboard is an electronic circuit board built into the computer that controls its mechanical functions, such as how the different parts of the computer communicate with one another and how power is used.
The longer computers were available, the more important computer networks became; this was especially the case after the Internet became widely available in the 1980s. Even computers that were not connected to the Internet often needed to be connected to one another, such as computers in an office that needed to be integrated into a local access network (LAN) for the company's employees. As it became increasingly common for computers to be part of a network, manufacturers began incorporating network interface controllers directly into the motherboard.
When wireless Internet technology gained popularity and availability in the twenty-first century, computer manufacturers responded by making the network interfaces wireless. These allow the computer to connect to a network without being wired in through Ethernet or other cabled connections, providing flexibility in placing a desktop computer and mobility for a laptop computer. These wireless network interface controllers, often referred to as WNICs, use antennas to connect to the wireless signals. Older computers that are not equipped with a WNIC can often be adapted with an NIC dongle, or a device that plugs into one of the computer's universal serial bus (USB) ports. In some cases, a computer might have two network interface controllers.
Overview
There are different types of network interface controllers. They are designed to fit in certain styles of computers and to function with different operating systems. In effect, the network interface transfers and translates information passed between the computer and the larger network.
The network interface controller makes it possible for the single bits of information sent through the network to be converted to the eight-bit format that computers receive. Bit stands for "binary digit" and represents the smallest unit of information encoded on a computer. The network interface controller both converts the information to the correct format, depending on whether the computer is currently receiving or sending information, and arranges it in a way that the computer can understand. This is known as formatting.
For a network interface to work, the network must be able to identify it. Each device includes a media access control (MAC) address permanently installed on the interface controller's ROM card. A read-only memory (ROM) card is a memory storage device. They are common in computers as well as digital cameras, video games, and other electronic devices. The MAC address serves as a sort of key to the computer; if the computer recognizes the MAC address as valid and thinks it matches the information for the computer, it will let the packet through. MAC addresses can also be used by network administrators to limit access to a network; the network can be programmed to recognize only certain MAC addresses and only allow those addresses to access the network, or to access only certain parts of the network. For example, in a school setting, there may be one level of access for student-assigned computers, another level for computers assigned to staff, and a third level for computers that are not known to the network, or guests.
The MAC address is a 48-bit code that is unique to each specific NIC. Information is passed from computer to computer in packets; a packet is a portion of data enclosed in additional information known as wrappers. They are also sometimes called buffers. A wrapper, which can be a header or trailer attached to the data packet to identify it, serves much like the wrapper on a takeout burger or sandwich to identify what is inside. The wrapper also helps to direct the packet to its intended destination.
When information needs to go from one computer in a network to another computer, it goes first from wherever it is on the computer to a protocol stack. Protocols are the rules for how data is handled; the stack refers to the software that implements the rules. In the protocol stack, the information is turned into a packet in a wrapper that identifies it and labels it with an intended destination. A single file may require multiple packets. In that case, the NIC labels them so that the information can be read properly at its destination.
The information packet then goes through the Ethernet hardware, which adds additional identifying information to a wrapper before sending the packet on its way. Once it arrives, the network interface controller will remove the information added by the Ethernet hardware at the sending computer. The packet is then sent to the protocol stacks, which further "unwrap" the packet before sending it where it belongs in the destination computer.
Network interface controllers provide an important way for data to flow from one computer to another. They allow for security both within the computer and within the network. Without them, computers would not be able to communicate with one another.
Bibliography
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