NIC

Synonyms

NIC
Network adapter
Network Interface Card

Network Card Overview

A network interface card is a type of expansion card and dedicated to one purpose, networking. An NIC allows communication among computers within a network. A network card contains connector to attach a cable such as twisted pair, BNC or AUI. NIC may contain LEDs to indicate some useful information such as data transmission indication. Network cards provide data rates of 10,100 to 1000 of mega bits per second.

Network Card Mac Address

IEEE allocates unique serial number to each network manufacturer. This serial number is 48-bit and is known as MAC address. The manufacturers neutralize this MAC address in firmware. Containing a MAC address it works at OSI model's layer 2.

MAC Address

IEEE assigns MAC Address to each manufacturer of network card. In the networks media access control address is assigned to the network equipment. Second layer protocol use these addresses to communicate or for other purposes. It is an identification number can belong to three categories MAC-48, EUI-48, and EUI-64, defined by IEEE.

Interface of Network Card

Earlier Computers network cards used to attach through the motherboard via expansion slots. Now a day NICs come integrated in the PCs. But still there are expansion slots are available to support network interface cards.

Network Card and OSI Layers

Network card as an embedded system (firmware & integrated circuit), is designed according to the OSI physical and data link layers. Physical and data link layers define the standards for communication among PCs. The standards include Ethernet, token ring and other network protocols. This protocol support allows implementing Local area networks (LANs) as well as wide area networks (WANs).

Network Card Data Transmission

Data transfers in four modes within a network. A network card can use any one or combination of these modes.

DMA

DMA direct memory access mode. In such case a peripheral can memory directly without any concern of microprocessor.

Programmed IO

In such technique a microprocessor allows / disallows the peripheral the use of system bus.

Interrupt Driven I / O

In this technique when peripheral is ready to transfer data, it interrupts the microprocessor to use the system bus.

Polling

In polling microprocessor checks the program, which is controlling the peripheral and assigns the priority with respect to the control.

Network Card Manufacturers

Networking is the major part of an organization whether it is a big or small. Now days no organization or industry can be considered complete without networks. The result is a huge demand of network cards. Therefore network card manufacturers have quite a completion among them. Here are the big manufacturers.

Intel, Novel, Marvell, AMD, VIA Networking, REALTEK, BROADCOM, 3COM Corporation, Digital Equipment Corporation, and ASIX Electronics.