Networks

Network Adapter

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Objective of this presentation

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Network Adapter (NIC)

Also known as a Network interface card. Integrated circuit board that plugs into

the internal circuitry of the computer. Allows the members of a local-area

network to communicate with each other.

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NIC is the physical interface from the computer or peripheral to the medium.

The Medium may be physical cable, such as twisted pair wiring, coaxial cable, fiber optic or even wireless.

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Role of NIC In networking

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This old ‘combo’ NIC accepts both BNC (coaxial) and RJ45 (UTP) connectors.

Network Cards Convert Data from Parallel to Serial, and vice versa

Most computers use parallel data lines internally to send data between the CPU and the adapter cards. This is called a Bus.

Most networking media transmit data in a single line, called serial transmission.

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The NIC translates parallel into serial for outgoing messages and serial into parallel for incomingmessages.

Prior to the invention of NICs, data was sent via serial ports on the computer.

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Serial port

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Need Of NICs Most computer networks transfer data

across a medium at a fixed rate, often faster than the speed at which computers can process individual bits.

To accommodate the mismatch in speed, each computer attached to a network contain special purpose hardware known as a network interface card (NIC).

The NIC functions like an I/O device: it is built for a specific network technology.

It handles the details of frame transmission or reception without requiring the CPU to process each bit

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Types of Network Interface Cards

Fiber-Optic Network Interface Cards work on a Fiber-Optic cabled network.

Infrared networking uses infrared light to transmit data from one device to another.

Wireless network cards with antennas operate on a wireless network with a wireless hub.

Copper wired Network Interface Cards work on coaxial cable or twisted-pair wire. 12

ETHERNET AND WIFI NICs

Some NIC cards work with wired connections while others are wireless.

Most NICs support either wired Ethernet or WiFi wireless standards.

Ethernet NICs plug into the system bus of the PC and include jacks for network cables.

while WiFi NICs contain built-in transmitters / receivers (transceivers).

The MAC Address

NICs have a unique identifier, called a Media Access Control (MAC) address. It is programmed into a ROM chip on the

NIC. It’s a 48-bit number, written as six two-digit

hexadecimal numbers separated by colons. The first part identifies the manufacturer. The second part is unique to each NIC.

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IP Address

Network Cards can have a second address called an IP address.

IP Address is software configurable. IP currently uses 32 bits split into four

sections separated by dots. i.e. 165.255.110.133 – These are decimal

values. Only used in certain network protocols such

as TCP/IP.

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WORKING

A computer or device on a network can be

reached by its MAC (media access control) address through the NIC card.

Every Ethernet network card has a unique 48-bit serial number called a MAC address, which is stored in ROM carried on the card.

The MACs on the network are used to direct traffic between the computers.

Cont..

An example of a MAC address: A1B2C3D4E5F6 The first 6 hex digits in the MAC address is the

OUI (organizationally unique identifier), assigned by the IEEE to each manufacturer (e.g. Cisco, Intel etc).

The rest of the MAC address can be assigned in any way by the manufacturer to the individual networking devices that it manufactures

Installation of NICs

The most common language or protocol for LANs is Ethernet, sometimes referred to as IEEE 802.3.

A lesser-used protocol is Token Ring. When building a LAN, a network interface card must be installed in

each computer on the network and all NICs in the network must be of the same architecture.

For example, all must either be Ethernet cards, Token Ring cards, or an alternate technology.

Cont.. An Ethernet network interface card is installed in an available slot

inside the computer. Most newer computers have a network interface built into the

motherboard. 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.

Network Interface Card for connection of a computer to an Ethernet Network

4. Driver Software

4.1. NIC Driver Configuration

4.2. Wireless NIC Configuration

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Device driver: small, specialized program that represents a device to an OS and manages communications between the OS and NIC

Incorrect/poorly written drivers can have negative impact on performance or prevent PC from booting

Major vendor standards for drivers

Network Device Interface Specification (NDIS)

Win32 Driver Model (WDM)

Open Data-link Interface (ODI)

Installing a driver for a NIC is usually easy

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4.1. NIC Driver Configuration

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Guide to Networking Essentials, Fifth Edition 26

4.2. Wireless NIC Configuration

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NICs on network

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.

Configuring a Network Interface Card

This involves three settings: Interrupt Request line (IRQ)

Base Input/Output (I/O) port

Base memory address

In older computers, the user needed to supply the IRQ and base I/O port. Currently Plug and Play operating systems have automated this task and default values are normally assigned.

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10Mbs Ethernet Card with an ISA Slot

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10baseT RJ45 Socket

Status LEDs

10Base2 BNCConnector

Mountingbracket

Each network cardhas a unique 48 bit identifierknown as the Media Access Control(MAC) number.

Network interface card

Network cards are typically available in 10/100/1000 Mbit/s varieties. This means they can support a notional maximum transfer rate of 10, 100 or 1000 Megabits per

second.

Electronic Components on the

Network Interface Card

Resistors

Diodes

Capacitors

Coils

Crystals

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Features of the Ethernet Controller

Scrambling: All the encoded data is passed to the data scrambler to reduce EMI by spreading the power spectrum using a 10-bit scrambler seed loaded at the beginning.

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Summary of the Network Interface Card

Allows connectivity of one computer to another.

Controls the communication that takes place between computers.

Utilizes an ethernet controller chip to encode, scramble, send and receive data.

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Conti

Converts data from parallel to serial for transmission to another Network Interface Card.

Comes in a variety of forms depending on the application or network medium.

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Question

1. A bridge makes forwarding decision based on what information .

Ip Address

Mac Address

Binary Address

Irq Address

2. On window 2000 System ,ifconfig/all command would you use to view the Mac Address

Yes /no36

Thank You

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