Network Interface card | How it works

Network Interface Card(NIC):

Ø  A network interface card (NIC) is a hardware component, typically a circuit board or chip, which is installed on a computer so that it can connect to a network. 

Ø  Without NIC a computer cannot be connected over a network.

Ø  A network interface Card is also known as a network interface controller, network adapter, LAN adapter or physical network interface, Ethernet Card, LAN card)

Ø  NIC allows both wired and wireless communications.

Ø  Network interface card is generally used for  communications between computers connected via local area network (LAN) as well as communications over large-scale network (Internet) through Internet Protocol (IP).

Ø  The NIC uses the OSI model to send signals at the physical layer, transmit data packets at the network layer and operate as an interface at the TCP/IP layer.

Ø  The network card operates as a middleman between a computer and a data network.

Ø   For example, when a user requests a web page, the computer will pass the request to the network card which converts it into electrical impulses. Those impulses are received by a web server on the internet and responds by sending the web page back to the network card as electrical signals. The card gets these signals and translates them into the data that the computer displays.

Ø  A NIC is a computer expansion card/Add-on card (It is a PCB that fits into an expansion slot on a desktop computer. It is used to give a computer additional capabilities.) for connecting to a network (e.g., home network or Internet) using an Ethernet cable with an RJ-45 connector.

Ø  Due to the popularity and low cost of the Ethernet standard, nearly all new computers have a network interface build directly into the motherboard.

Ø  NIC is divided into two types

A)   Internal Network Card (Ethernet NIC card)

Ø  In internal networks cards, motherboard has a slot for the network card where it can be inserted.

Ø  These NICs have input jacks made for cables to provide network access where we have to plug one end of the ethernet cable into the slots of the computer and another end of the cable is plugged into the modem 

Ø  The most popular wired LAN technology is Ethernet.

B)   External Network Card

Ø  In desktops and laptops that do not have an internal NIC, external NICs are used.

Ø  External network cards are of two types: Wireless and USB based.

Ø  Wireless network card needs to be inserted into the motherboard; however, no network cable is required to connect to the network. They are useful while traveling or accessing a wireless signal.

Ø  Wireless NICs are designed for Wi-Fi connection.

Ø  Wireless network NIC cards consist of a small antenna to provide wireless reception through radio frequency waves integrated onto the card, where the communication between various devices is set up wirelessly using the router and various network protocols.

Ø  USB Network Card: These are NICs that provide network connections through a device plugged into the USB port.

Components of NIC:

Ø  An external Memory is used to store the data temporarily and uses the stored data whenever required while processing the communication.

Ø  Connectors are used to make the physical link between cables and plugin with the board, this type of connection is especially seen in Ethernet type of NIC cables.

Ø  A Processor converts the data message into a signal format for communication to take place easily.

Ø  Jumpers or Dual in package switches are used to control the communication operation, which is either by turning on or turning off the switch.

Ø  MAC address which is a unique identity address is given to network interface card.MAC address is also known as a physical network address.

Ø  A router: In this case, the NIC connects to the router which is connected to the internet.

Ø  Driver - This is the required software that passes data between the computer's operating system (OS) and the NIC. When a NIC is installed on a computer, the corresponding driver software is also downloaded. Drivers must stay updated and uncorrupted to ensure optimal performance from the NIC.