Nic
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Transcript of Nic
Network Interface Card
Why NIC
In the early days of computing, individual computers
operated as stand-alone systems. In order to transfer
files between computers, you had to use a portable
storage medium such as a floppy disk.
However, in modern day computers, connecting to a
network is essential.
A computer uses a network interface card (NIC) to
become part of a network.
Network Interface Card
Also known as a Network Adapter.
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.
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.
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.
The NIC translates parallel into serial for outgoing
messages and serial into parallel for incoming
messages.
LAN Card
The LAN (Local Area Network) card is a 'door' to the network from a computer. Any type of network activity requires a LAN card: the Internet, network printer, connecting computers together, and so on.
Today many devices contain a network card, including televisions for their Internet apps, Blu-ray players, mobile phones, VoIP, desk phones, and even refrigerators.
LAN Card Types
There are many other ways of connecting the LAN
card to a computer.
Some cards are connected via the USB port, some via
the PCI port inside of the computer, and some are
even embedded inside of the computer.
Ethernet port, which is the spot where you plug in a
network cable. The LAN card you select often
determines the protocols that are used on the network.
Functions of LAN Card
The purpose of a LAN card is to create a physical
connection to the network - to provide an open
'door,' as it were. The first interface supported by a
LAN card is a physical interface through which the
cable plugs into the card.
The second function of LAN card is to provide a
data link.
IP Address
An Internet Protocol address (IP address) is a numerical label assigned to
each device (e.g., computer, printer) participating in a computer
network that uses theInternet Protocol for communication.
Explicit address
It is an identifier for a computer or a device on a TCP\IP network
Network using TCP\IP protocol routes message based on IP address of the
destination
Its role can be categorized as
Name-indicating what we seek
Address-indicating where it is
Route-indicating how to get it
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
An IP address serves two principal functions: host
or network interface identification and
location addressing.
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.
Ethernet Connection
The most widely used network connection for
personal computers is an Ethernet connection.
Since Ethernet is so widely used, most modern
computers have a NIC built into the motherboard.
An Ethernet connection uses a standard interface
known as a RJ45 connector. RJ stands for
registered jack.
The Basic Ethernet Frame Format
It contains the following seven fields :
13
Preamble (PRE)—Consists of 7 bytes and is an alternating pattern of ones and zeros that tells the receiving stations that a frame is coming.
Start-of-frame delimiter (SOF)—Consists of 1 byte.
Destination address (DA)—Consists of 6 bytes and identifies which station should receive the frame.
Source addresses (SA)—Consists of 6 bytes and it identifies the sending station.
Length/Type—Consists of 4 bytes and indicates the number of MAC-client data bytes.
Data—Is a sequence of 1500 bytes maximum.
Frame check sequence (FCS)—Consists of 4 bytes and this sequence contains a 32-bit cyclic redundancy check (CRC).
Basic MAC Data Frame Format
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Transmission order, left to right, bit
serial.
D
Configuring a Network Interface Card
15
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.