The Physical Layer is associated with the transmission media. It defines the mechanical, electrical and procedural standards for transmitting raw bits over a communication channel.

1. Introduction to TCP/IP
Introduction to TCP/IP

2. OSI Model
• The OSI (Open Systems Interconnection) model is a
layered framework for the design of network
systems that allows communication between all
types of computer systems.
• It consists of seven separate but related layers.
• Each layer defines a part of the process of moving
information across a network.
• An OSI model provides a solid basis for
understanding data communications.
Introduction to TCP/IP

3. Layered Architecture
• .
• Each layer performs unique and
specific task and it offers services
to the layer above it.
• For example, Layer 3 uses the
services provided by layer 2 and
provides services for layer 4.
Introduction to TCP/IP

4. TCP/IP MODEL
• The Internet Protocol Suite (commonly known as TCP/IP)
is the set of communications protocols used for the
Internet and other similar networks.
• It is named from two of the most important protocols in it:
• The Transmission Control Protocol (TCP) and
• The Internet Protocol (IP), which were the first two networking
protocols defined in this standard
Introduction to TCP/IP

5. The Transport Layer
Introduction to TCP/IP
• This layer acts as the delivery service used by
the application layer.
• The two protocols used are TCP and UDP.
• The choice is made based on the application's
transmission reliability requirements.
• The transport layer also handles all error
detection and recovery.

6. The Transport Layer
Introduction to TCP/IP
• The Transport Layer is responsible not only for application
addressing, but also for providing reliable communications
over the best effort Layer 3 protocols.
• The Transport Layer provides:
• Flow control
• Windowing
• Data sequencing
• Recovery

7. Multiplexing Using TCP Port
Numbers
Introduction to TCP/IP
Multiplexing relies on the use of a
concept called a socket. A socket
consists of three things:
An IP address
A transport protocol
A port number

8. The Network Layer
Introduction to TCP/IP
• Provides services to exchange packets over the
network between identified end devices
• To accomplish this end-to-end Transport, Network
Layers uses 4 basic processes:
• Addressing
• Encapsulation
• Routing
• De-encapsulation
Segment
Packet
Frame

9. Encapsulation example: E-mail
Introduction to TCP/IP

10. The Data-Link Layer
Introduction to TCP/IP
• Handles the moving of data into and out of a
physical link in a network.
• It ensures that the pace of the data flow
doesn’t overwhelm the sending and receiving
devices.
• This layer also permits the transmission of
data to Layer 3, the network layer, where it is
addressed and routed.
• Handle errors by implementing an
acknowledgement and retransmission
scheme.

11. Physical Layer
• It co-ordinates the functions required to
transmit bit stream over physical medium.
• Provides physical interface for transmission of
information.
• Defines rules by which bits are passed from one
system to another on a physical communication
medium.
• Covers all - mechanical, electrical, functional
and procedural - aspects for physical
communication.
Introduction to TCP/IP

12. Summary
Introduction to TCP/IP

13. Remembering the 7 Layers
7 - Application All Away
6 - Presentation People Pizza
5 - Session Seem Sausage
4 - Transport To Throw
3 - Network Need Not
2 - Data Link Data Do
1 - Physical Processing Please

14. Que.: Name the layer which is associated with the
transmission media.