Download Local Area Network

Network
Telecommunications
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A collection of computers
There are three types of networks
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Local Area Networks
Wide Area Networks
Internets
Local Area Networks can have two to several
hundred at a single location
Wide Area Networks can connect two offices –
one in California and the other in New York
Internets use a collection of networks
Network
Software
Network
Operating
System
Network Interface Card
Network Connection
Network Server
Workstation
Software
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Enables the server to manage
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Data
Users
Groups
Security
Applications
And other Functions associated to needs of the Network
Other Benefits
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Allows remote users to connect
Permits users to connect to the Internet
Enables additional clients and resources
Monitor the status and functionality of the network
Distribute programs and software updates to clients
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All computers have NIC built-in
They come with there own Media Access Control
(MAC) address
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Has an unique identifier supply by the manufacture
It enables you to be tracked on the internet
Your IP is left behind wherever you go
Without it – you would not be able to share files or
interact with the internet
Bottom line – it permits you to access the internet or a
specific networks
SERVER
NOS
Computer
HUB
Multiplexer
Computer
Switch
Multiplexer
Computer
Switch
Multiplexer
Router
Peer
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Default Gateway
They sent information using the best path to
deliver – using multiple networks
They direct traffic across the networks
They connect to two or more data lines from
different networks
Data comes in from one line – router reads the
address in the packet to determine its
destination
IP: 192.168.23.77
Subnet Mask: 255.255.253.0
IP: 172.30.34.222
Subnet Mask: 255.255.255.0
4
4
IP: 192.168.23.77
SM: 255.255.253.0
IP: 172.30.34.222
SM: 255.255.255.0
Network ID: 192.168.23.77
Network ID: 172.30.34.222
Router
LAN
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Are simply a repeater !
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It has no intelligences to separate conversations
 It’s a dumb device
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A hub sees a bit or receives a signal – they simply are
going to repeat it – and send the packet of data to a
connecting devices or Node
 To all connecting devices
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It has no knowledge of IP addresses
 This is where the term dummy device comes from
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It sends one large bandwidth of information
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Node is Latin for “Knot” Refers to a “connecting point”
or a redistribution point!
Disadvantage! It has no
intelligence to separate
conversations
Provides one huge broadcast to
every port or every device
Betty
It can cause a collusion with
others sending a broadcast
Only one speaker can be talking
at one time
David
Carol
John
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Replicated Data
i.e. Star Network
Is a distributed application
that partitions tasks or
workloads between peers
(Shares Resources)
It provides a portion of
resources such as
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Gaming
Chat Room
Shared Resources
Processing power
Disk storage
Cheap, Easy, and
Expandable
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How are we able to connect with other networks
How does the network know how to transfer
information from one point to another
How does the network know that the delivery
point is correct
How is it possible for me to view my corporate
email from multiple computers
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The methodology of sending a file over a
network – resembles circuit switching
It selects the quickies route using circuits
The bigger the file the long it will take to
receive the file
It breaks down big files to smaller files without
overloading the network
It has intelligences as it will decide on the
fastest route that is less traveled
Betty
Steve
1. Doesn’t reserve the entire network from point-A to point-B
2. Makes better use of the network by taking the quickest route
3. It numbers the files, sorts them out, and eliminates bottle necking
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TCP/IP
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Is a set of standards used by computers to transmit data
across wires or wirelessly
Standards are hardcoded into each computer so that one
computer sends information to another, they are both
using the same methods to translate that data
The most common protocol
 TCP/IP is an international set of protocols to send and
receive information between two points in a network
TCP/IP Stack
Application Layer
Data
Data
Data
Transport Layer
Segments
Internet Layer
Packets
Network Layer
Frames
Bits
Application
Process to Application
Presentation
Data Rep. & Encryption
Session
Inter Communication
Transport
End-to-End Connections
Network
ROUTER
Path Determination
Data Link
SWITCH
Physical Addressing
Physical
HUB
Binary Transmission
Octet
IP = 192.168.05.66
Each Octet can have a number ranging from 0-255
Each Octet = 8-bits
Four Octets = 32-bit long and the network reads it as a single string
MOVING to the Future = IPv6 = 128-bit strings
Sub-Network
Human
Resources
Network ID
Modem
Sub-Network
Accounting
Department
Topology
Internet
IP: 255.25.25.02
WAN
LAN
Switch
Sub-Network
Multiplexer
Router
Gateway
Sales
Department
IP: 255.25.25.01
Router
Sub-Network
Marketing
Department
Sub-Network
Production
Department
Switch
Multiplexer
IP: 255.25.25.03
Web
Server
Proxy
Server
Switch
Multiplexer
Sub-Network
Procurement
Department
Network
Server
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It is a band of frequencies
First (back in the day) used in radio
 The wider (or Broader) the bandwidth of a channel the greater the capacity for traffic
 Refer to fast data transmission rates
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Divided into channels
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Voice or data channels simultaneously
Can be use as a high-speed single channel data
transmission
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Allows us to connect to the internet
Enables us to transmit and receive
Information
 Voice
 Data
 Video
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Supplies content from the web
Enables us to download applications
Measured by speed or bits per second
Modulator/Demodulator or Modem
Enables switching: Voice/Data
Data Compression
1
1
1
1
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1
8 bits = 1-Byte
01000001 = A
01100001 = a
0
0
0
Transformed into
Bit/Binary
*POTS*
Electronic Pulses
Telephone line
Cable system
Wireless
Analog devices
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Uses
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Telephone line
 (DSL) Digital Subscriber Line
Satelite dishes
 Radio Waves
 Cable (ISP)
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To span larger geographic
areas
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Small Office or Home
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Broadcast is limited
To the area of a Home
 Small office Area
 Radius = 50 ft.
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Corporations
Much more powerful
broadcast
 Install Repeaters
 More coverage
 Radius = 1,640 Ft.
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Has intelligences
Memorizes MAC addresses
 It knows where everyone lives within the network
 Delivers information to only the MAC address in
which it is intended
 Other PC’s attached to the switch would never know
about the information being forwarded
 It allows more throughput
 All PC’s connections has full bandwidth
 No one will experience a collision
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Nancy
Debbie
All members are a part of the
same broadcast domain
PC #1
IP: 198.22.254.1
Bill
PC #3
IP: 197.44.197.2
Uses: 1-line for receiving and 1-line
for sending to each device
It can use both simultaneously
There is no collisions because it has
a dedicated road to travel
PC #2
IP: 185.33.188.5
Janet
PC #4
IP: 174.54.112.8
Corp
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The term is Greek = “Place” or “study”
It is the layout pattern on interconnections
 It is the physical or logical methodology of the
network
 It is the virtual shape or structure of a network
 Physical design is the devices on the network
 Office layout, what is going to connect to the
network
 Logical refers to how data is actually going to be
transferred within the network (OSI Model)
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Corp
Difficult to trouble
shoot!
To add a node – network
must be shut down
Host IP:
125.41.48.122
Host IP:
125.41.48.121
Host IP:
125.41.48.123
Ring
Network
IP:
255.25.24.01
Host IP:
125.41.48.123
Corp
YOUR
IT!
Host IP:
125.41.48.124
P/Domain
IP: 255.25.25.01
Network ID
IP: 255.25.25.02
Old LAN’s uses legacy Token Ring network software!
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Very fast transfer rates – all traffic (packets)
travels in the same direction
Adding other nodes – have little impact on
bandwidth
Prevents network collisions
One cable configuration
Disadvantages – for all computers to communicate
with each other, all computers must be turned on!
Peer-to-peer connection
to each node
HUB
If a node fails –
it will have very
little effect on
the network
Disadvantage: The hub represents a single point of failure!
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Each network host is connected to a central hub
Connects each node to the hub with a P2P
connection
All traffic passes through the central hub
Easy to added more nodes
Usually uses a HUB and a Switch to complete
the network!
Corp
Sales Sub-Network
Marketing Sub-Network
1-broadcase domain
1-broadcase domain
HUB
Switch
Logical IP address
IP 255.255.255.1
Enables
forwarding
messages by
acknowledging
logical IP
address
Logical IP address
IP 255.255.255.2
Corp
One virus – everyone
is affected!
Most common network!
Limited cable length
& number of stations
Disadvantage – although it is cheap to install, this type of network
only has one wire – therefore, it can be a single point of failure
If the network cable breaks, the entire network will be down!
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All nodes of the network are connected to a
common transmission, which has two endpoints
Data travels in both directions until the MAC
address is found
It has only 1-wire, very inexpensive to
implement