Here you will learn:
How to Connect two or more devices to share data and information.
What is OSI Model?
Introduction to OSI Model
What is Physical Layer?
Devices used Physical Layer
What is Signal?
Types of Signals?
Analog Signals
Digital SIgnals
What is Transmission Medium?
What Is Switch in Networking?
Networking 7 Layers.
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Please like and comments your Question and suggestion?
2. Introduction
• How to connect two or more devices?
• OSI Model
--> Open Systems Interconnect
Set of protocols
• Introduced in first time in 1770s by ISO
(International Standards Organization)
• Composed of 7 Layers
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Physical Layer 2
3. 7.Application Layer
6.Presentation Layer
5.Session Layer
4.Transport Layer
3.Network Layer
2.Data Link Layer
1.Physical Layer
Advice
Person
Sales
Trust
Not
Do
Please
OSI Model Layers
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3Physical Layer
4. PHYSICAL LAYER
• It deals with the mechanical and electrical
specifications (Devices)
• Physical characteristics of interfaces and
medium.
• To move data in the form of electromagnetic
signals across a transmission medium
• The physical layer data consists of a stream of
bits (sequence of Os or 1s)
• Bits are encoded into signals
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4Physical Layer
6. Signals
A signal is an electric current
or electromagnetic field used to convey data
from one place to another.
A Transmitter encodes a message into a
signal, which is carried to a receiver by the
communications channel.
Signals can be interpreted as either Analog or
Digital
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6Physical Layer
7. Digital Signals
• Digital signals are non-continuous, discrete
7
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Physical Layer
8. Analog Signals
• Analog signals are continuous, non-discrete
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8Physical Layer
9. Devices
Some of the common devices are:
Hub
Switch
Repeater
Bridge
Modem
PC, Mobile phone, Telephone or Cables etc are
also devices use for data communication.
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9Physical Layer
10. Hub
• Centralize device that connects many
devices to share data
• Less secure
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10Physical Layer
11. Switch
• Device that connects many other devices
together to make a network
• More intelligent then Hub
• More secure
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11Physical Layer
12. Repeater
• Regenerates the signal (Electrical, Wireless or
Optical) which are corrupted due to long
distance
• Overcome the distance limitations of the
transmission media.
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12Physical Layer
13. Bridge
• Creates a single aggregate network from
multiple communication networks
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13Physical Layer
14. Modem
• The word Modem comes from Modulator-
Demodulator
• Modulation: Digital signals to analog
• Demodulation: Analog signals back to Digital
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14Physical Layer
15. Physical Topologies.
How the devices are connected to make a
network ?
Mesh topology
Star topology
Bus topology
Ring topology
Hybrid topology
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21. Transmission Medium
• Anything that can carry information from a
source to a destination.
• Uses cables or electromagnetic signals
to transmit data.
Types of Transmission Media
• 1. Wired or Guided Media or Bound Transmission
Media
• 2. Wireless or Unguided Media or Unbound
Transmission Media
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21Physical Layer