Introduction to Networks

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Introduction to Networks
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Network
A communication system that enables many users to
share computer resources such as personal
computers, application software, data/voice/video
information, host computers, and printers.
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Advanced Network
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File Server
File Server A computer and operating system that
enables multiple access to other computers so
that software applications and data files can be
shared.
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Host
This type of computer has an operating system
that allows several computers to access it at the
same time. Programs and information may be
processed at the host or they may be downloaded
to the accessing computer for processing.
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Client
A computer that is used to access a file
server,or another computer which allows multiple
access. The client may use the accessed computer
in order to process data. Other software and
data may be transferred from the main computer to
the client for processing.
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Workstation
This is any computer that has a CPU. The
workstation may be used as a stand-alone computer
for word processing, spreadsheet creation, or
other software applications. It also may be used
to access another computer such as a file server.
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Client/Server
Many software applications are being written
based on networking capabilities. In
client/server systems, processing of data occurs
at the workstation (client) and on the host or
server. (Example Exchange)
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Common Network Elements

• Nodes
• Cabling
• Data Packets
• Addressing
• Communication Software
• Data Transmission Rate

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Node
Any device or entity connected to a network is a
node. Network-connected personal computers, file
servers, printers, and mainframes are individual
nodes.
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Cabling

• This is the electrical wire used to connect
  equipment in order to have a network.
• The cable provides a
• medium for the
• electrical signal that
• carries information
• from one networked
• computer to another.

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Network Interface Card (NIC)

• This electrical circuit board is used by
  computers, printers, and other equipment so they
  are able to connect to a network and transfer
  data.

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Spread Spectrum Technology (SST)
This is used by wireless networks in place of
cable so that network equipment can communicate
with other equipment attached to the network.
Network data is transmitted by means of high
frequency radio signals.
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Data Packet
This is the unit of information that is sent from
one network node to the next. A computer on the
network forms data into small distinct units. The
data filled units are sent one-at-a-time to the
receiving computer.
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Transmission Rate
This is the speed at which data packets are
transported on a network. Transmission rate is
affected by network topology and the medium. On
some networks the speed may be as low as 1
megabits per second (Mbps), and on others it may
be over 100 Mps.
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Address
Network equipment is identified by means of a
unique number. No two network computers,
printers, or other network equipment will have
the same number or address assigned to them.
130.17.12.167
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Network Nodes with Addresses
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Protocol
An established guideline that determines how
networked data are formatted into a packet, how
they are transmitted, and how they are
interpreted at the receiving end.
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Protocols
Transmission Control Protocol/Internet Protocol
(TCP/IP) This is two protocols combined into one.
TCP is a reliable connection-oriented data
transfer method that uses connectionless routing
provided by IP. Internetwork Pack Exchange (IPX)
This protocol is used by Novell NetWare and
provides best-effort delivery of data packets.
This protocol uses a variation of the data
transfer algorithm known as routing information
protocol. Sequenced Packet Exchange (SPX) This
protocol is packet oriented and relies on
sequence numbers or acknowledgments (provided by
the packet) for data transmission.
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Types of Networks
Local Area Network (LAN) This is a series of
interconnected computers, printers, and other
computer equipment that share hardware and
software resources. The service area is usually
local to a given floor, office area, or building.
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Types of Networks
Metropolitan Area Networks (MAN) This consists of
several LANs that are connected to one another
or a network that reaches throughout a large
area, such as a city or a large college campus.
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Types of Networks
Wide Area Network (WAN) A far reaching system of
networks is called a WAN. WANs can extend across
states and across continents. They make it
possible for thousands of users to send data to
one another.
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Network Capabilities

• Electronic mail (e-mail)
• File and print services
• Host access - Remote Access Server
• Client / server software
• Information networks - Internet

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Introduction to Networks