Information about Network card

For the discount card available for rail travel in South East England, previously called the "Network Card", see .

Network Card
A 1990s Ethernet network interface controller card which connects to the motherboard via the now-obsolete ISA bus.
Connects to: Motherboard via one of Integrated PCI Connector ISA Connector PCI-E Network via one of Fast Ethernet Gigabit Ethernet Optical fiber Token ring
Speeds: 10 Mbit/s 100 Mbit/s 1000 Mbit/s up to 160 Gbit/s
Common Manufacturers: Novell Intel Realtek Others

A network card, network adapter or NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network. It is both an OSI layer 1 (physical layer) and layer 2 (data link layer) device, as it provides physical access to a networking medium and provides a low-level addressing system through the use of MAC addresses. It allows users to connect to each other either by using cables or wirelessly.

Although other network technologies exist, Ethernet has achieved near-ubiquity since the mid-1990s. Every Ethernet network card has a unique 48-bit serial number called a MAC address, which is stored in ROM carried on the card. Every computer on an Ethernet network must have a card with a unique MAC address. No two cards ever manufactured share the same address. This is accomplished by the Institute of Electrical and Electronics Engineers (IEEE), which is responsible for assigning unique MAC addresses to the vendors of network interface controllers.

Whereas network cards used to be expansion cards that plug into a computer bus, the low cost and ubiquity of the Ethernet standard means that most newer computers have a network interface built into the motherboard. These motherboards either have Ethernet capabilities integrated into the motherboard chipset, or implemented via a low cost dedicated Ethernet chip, connected through the PCI (or the newer PCI express bus). A separate network card is not required unless multiple interfaces are needed or some other type of network is used. Newer motherboards may even have dual network (Ethernet) interfaces built-in.

The card implements the electronic circuitry required to communicate using a specific physical layer and data link layer standard such as Ethernet or token ring. This provides a base for a full network protocol stack, allowing communication among small groups of computers on the same LAN and large-scale network communications through routable protocols, such as IP.

There are four techniques used to transfer data, the NIC may use one or more of these techniques.

Polling is where the microprocessor examines the status of the peripheral under program control.
Programmed I/O is where the microprocessor alerts the designated peripheral by applying its address to the system's address bus.
Interrupt-driven I/O is where the peripheral alerts the microprocessor that it's ready to transfer data.
DMA is where the intelligent peripheral assumes control of the system bus to access memory directly. This removes load from the CPU but requires a separate processor on the card.

A network card typically has a twisted pair, BNC, or AUI socket where the network cable is connected, and a few LEDs to inform the user of whether the network is active, and whether or not there is data being transmitted on it. The Network Cards are typically available in 10/100/1000 Mbit/s(Mbit/s). This means they can support a transfer rate of 10 or 100 or 1000 Megabits per second.

Notable manufacturers

Ethernet is a family of frame-based computer networking technologies for local area networks (LANs). The name comes from the physical concept of the ether. It defines a number of wiring and signaling standards for the physical layer, through means of network access at the Media
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ISA
Industry Standard Architecture

Five 16-bit and one 8-bit ISA slots on a motherboard
Year created: 1981
Created by: IBM
Superseded by: PCI (1993)

Width:

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PCI
Peripheral Component Interconnect

five 32-bit PCI expansion slots on a motherboard
Year created: Mid-1993
Created by: Intel
Superseded by: PCI Express (2004)

Width:

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ISA
Industry Standard Architecture

Five 16-bit and one 8-bit ISA slots on a motherboard
Year created: 1981
Created by: IBM
Superseded by: PCI (1993)

Width:

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This article or section may be confusing or unclear for some readers.
Please [improve the article] or discuss this issue on the talk page. This article has been tagged since February 2007.
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In computer networking, Fast Ethernet is a collective term for a number of Ethernet standards that carry traffic at the nominal rate of 100 Mbit/s, against the original Ethernet speed of 10 Mbit/s.
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Gigabit Ethernet (GbE or 1 GigE) is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second, as defined by the IEEE 802.3-2005 standard.
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An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length. Fiber optics is the overlap of applied science and engineering concerned with such optical fibers.
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Token ring local area network (LAN) technology was conceived in the late 1960s by Olof Söderblom, then working for IBM [1] ). US Patents were awarded in 1981 and Token-Ring was developed and promoted by IBM in the early 1980s and standardized as IEEE 802.
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Novell Inc.

Public (NASDAQ: NOVL )
Founded Provo, Utah (1983)
Headquarters Waltham, MA, USA

Key people Ron Hovsepian, CEO and President
John Dragoon, Senior Vice President, CMO
Dana Russell, Senior Vice President, CFO
Industry Software
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Intel Corporation

Public (NASDAQ: INTC , SEHK: 4335 )
Founded 1968 ¹
Headquarters Santa Clara, California
United States

Key people Paul S.
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Realtek Semiconductor Corp. (Traditional Chinese: 瑞昱半導體股份有限公司), a fabless IC design house situated in the Hsinchu Science Park, Hsinchu, Taiwan, was founded in October 1987, and subsequently
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Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. The hardware of a computer is infrequently changed, in comparison with software and data, which are "soft" in the
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as a college campus, industrial complex, or a military base. A CAN, may be considered a type of MAN (metropolitan area network), but is generally limited to an area that is smaller than a typical MAN.
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Open Systems Interconnection Basic Reference Model (OSI Reference Model or OSI Model for short) is a layered, abstract description for communications and computer network protocol design, developed as part of the Open Systems Interconnection (OSI) initiative.
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physical layer is level one in the seven-level OSI model of computer networking as well as in the five-layer TCP/IP reference model. It performs services requested by the data link layer.
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data link layer is layer two of the seven-layer OSI model as well as of the five-layer TCP/IP reference model. It responds to service requests from the network layer and issues service requests to the physical layer.
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In computer networking a Media Access Control address (MAC address) or Ethernet Hardware Address (EHA) or hardware address or adapter address is a quasi-unique identifier attached to most network adapters (NICs).
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The notion of read-only data can also refer to file system permissions.

Read-only memory (usually known by its acronym, ROM) is a class of storage media used in computers and other electronic devices.
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Institute of Electrical and Electronics Engineers

Type Professional Organization
Founded January 1, 1963
Origins Merger of the American Institute of Electrical Engineers and the Institute of Radio Engineers
Key people Leah H.
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Expansion Card

Fitting an expansion card into a motherboard
Date Invented: 1974
Invented By: MITS
Connects to:

Motherboard via one of

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Motherboard

The ASUS CUSL2-C motherboard

Connects to:

Microprocessors via sockets
Main memory via Slots
Peripherals

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PCI
Peripheral Component Interconnect

five 32-bit PCI expansion slots on a motherboard
Year created: Mid-1993
Created by: Intel
Superseded by: PCI Express (2004)

Width:

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Network Card

Notable manufacturers

See also