Networking Solutions
Chapter 2 – The OSI Model

Similar to a company like
◦
◦
◦

Advantages
◦ Divides the network into
◦ Multiple vendors can
◦ Encourages
◦ Prevents changes in one layer
The Layered Approach
7
6
5
4
3
2
1
Application
Presentation
Session
Transport
Network
Data link
Physical
The OSI Model

Where the user

Apps like IE interact with

Note on page
Application Layer

Presents data to the Application Layer and is
responsible for

layer
and
Presentation Layer
occur at this

Responsible for

Coordination is established in
Session Layer

Segments and
(connection-oriented) or
(connectionless)


SYN / ACK

Flow
Transport Layer

Addressing of

Track

Determines

Packets sent are either
Network Layer

Provides

Routers don’t care

Switches care about

Two sublayers:
Data Link Layer


Sends
is defined at this layer
Physical Layer

Router points on page 47

802.X on pages 49 / 50

Encapsulation on page 51
Other “stuff” to know