ISTN3ND CHAPTER ONE
NETWORKING
SUMMARIES, PRACTICE QUESTIONS AND ANSWERS
, 1
Table of Contents
Network Types and Architectures.......................................................................................................... 2
LAN/WLAN Network .............................................................................................................................. 2
✓ Example: Home ......................................................................................................................... 2
BACKBONE Network .............................................................................................................................. 2
INTRANET/EXTRANET .......................................................................................................................... 3
LABS .......................................................................................................................................................... 3
DIAGNOSE ................................................................................................................................................ 4
OSI vs TCIP/IP Model................................................................................................................................. 5
OSI MODEL EXPLAINED ......................................................................................................................... 5
Layer 7: Application Layer ................................................................................................................ 5
Layer 6: Presentation Layer .............................................................................................................. 5
Layer 5: Session Layer ....................................................................................................................... 5
Layer 4: Transport Layer ................................................................................................................... 5
Layer 3: Network ............................................................................................................................... 6
Network layer deals with LOGICAL ADDRESSING. .......................................................................... 6
Layer 2: Data Link Layer ................................................................................................................... 6
Layer 1: Physical Layer ...................................................................................................................... 6
TCIP/IP MODEL ....................................................................................................................................... 6
Layer 4: Application Layer ................................................................................................................ 6
Layer 3: Transport Layer ................................................................................................................... 7
Layer 2: Internet Layer ...................................................................................................................... 7
Layer 1: Network Access Layer ........................................................................................................ 7
LAB ........................................................................................................................................................ 7
DIAGNOSE ............................................................................................................................................ 8
Protocols and PDUs Explained ................................................................................................................ 9
It is a consistent framework. ............................................................................................................... 9
The Universal Framework .................................................................................................................... 9
Protocols are used to create PDU in each layer. Hence it is very important to know what
each layer is, what PDU is used and what protocol is used and why they are used. You will
always start with your application layer and go down, that’s your starting point and your
network access layer or physical layer is your ending point. .................................................... 11
These are applicable in any scenario - just learn the format and you can always apply it! 11
LAB .......................................................................................................................................................... 12
DIAGNOSE .............................................................................................................................................. 12
, 2
Chapter One
Network Types and Architectures
Let's look at the different types of networks we build. We typically categorize them in two
main ways: by their geographic scope and by their access or purpose.
First, geographic scope. This is the most common way to think about networks, from the
smallest to the largest. This is just focusing on where the network is located.
LAN/WLAN Network
Starting small, we have the Local Area Network (LAN). This is your home network, your
office floor, a school campus. The key characteristic is that it's under one administrative
control and covers a limited geographic area. You own the switches, the cables, the Wi-Fi
access points. When a LAN uses wireless circuits, we specifically call it a WLAN—your home
Wi-Fi is a perfect example.
(How to identify networks according to geographic scope: What is their coverage and
who has control?)
✓ Example: Home
✓ Control: Family members has access to switches, cables, routers and to wireless
access points. - One Administrative Control
✓ Coverage: Limited to geographic area of Home
✓ Diagnosis: LAN Network
✓ Using: Wireless circuits - Diagnosis: WLAN Network
BACKBONE Network
Now, what happens when a single LAN isn't enough? Imagine a university with separate
LANs for the library, the engineering building, and the dormitories. These LANs need to talk
to each other. We connect them using a Backbone Network (BN). Think of the BN as the
"network of networks," the central infrastructure that ties all the LANs together. It's a high-
speed network designed to carry a massive amount of aggregated traffic. It might span a
campus or a large corporate park
BackBone Lecture
Cafeteria Library
Network Halls
Single Lan Network
Single Lan Network
Nework that is binding all
the Single LAN networks Single Lan Network
together allowing
communication.
NETWORKING
SUMMARIES, PRACTICE QUESTIONS AND ANSWERS
, 1
Table of Contents
Network Types and Architectures.......................................................................................................... 2
LAN/WLAN Network .............................................................................................................................. 2
✓ Example: Home ......................................................................................................................... 2
BACKBONE Network .............................................................................................................................. 2
INTRANET/EXTRANET .......................................................................................................................... 3
LABS .......................................................................................................................................................... 3
DIAGNOSE ................................................................................................................................................ 4
OSI vs TCIP/IP Model................................................................................................................................. 5
OSI MODEL EXPLAINED ......................................................................................................................... 5
Layer 7: Application Layer ................................................................................................................ 5
Layer 6: Presentation Layer .............................................................................................................. 5
Layer 5: Session Layer ....................................................................................................................... 5
Layer 4: Transport Layer ................................................................................................................... 5
Layer 3: Network ............................................................................................................................... 6
Network layer deals with LOGICAL ADDRESSING. .......................................................................... 6
Layer 2: Data Link Layer ................................................................................................................... 6
Layer 1: Physical Layer ...................................................................................................................... 6
TCIP/IP MODEL ....................................................................................................................................... 6
Layer 4: Application Layer ................................................................................................................ 6
Layer 3: Transport Layer ................................................................................................................... 7
Layer 2: Internet Layer ...................................................................................................................... 7
Layer 1: Network Access Layer ........................................................................................................ 7
LAB ........................................................................................................................................................ 7
DIAGNOSE ............................................................................................................................................ 8
Protocols and PDUs Explained ................................................................................................................ 9
It is a consistent framework. ............................................................................................................... 9
The Universal Framework .................................................................................................................... 9
Protocols are used to create PDU in each layer. Hence it is very important to know what
each layer is, what PDU is used and what protocol is used and why they are used. You will
always start with your application layer and go down, that’s your starting point and your
network access layer or physical layer is your ending point. .................................................... 11
These are applicable in any scenario - just learn the format and you can always apply it! 11
LAB .......................................................................................................................................................... 12
DIAGNOSE .............................................................................................................................................. 12
, 2
Chapter One
Network Types and Architectures
Let's look at the different types of networks we build. We typically categorize them in two
main ways: by their geographic scope and by their access or purpose.
First, geographic scope. This is the most common way to think about networks, from the
smallest to the largest. This is just focusing on where the network is located.
LAN/WLAN Network
Starting small, we have the Local Area Network (LAN). This is your home network, your
office floor, a school campus. The key characteristic is that it's under one administrative
control and covers a limited geographic area. You own the switches, the cables, the Wi-Fi
access points. When a LAN uses wireless circuits, we specifically call it a WLAN—your home
Wi-Fi is a perfect example.
(How to identify networks according to geographic scope: What is their coverage and
who has control?)
✓ Example: Home
✓ Control: Family members has access to switches, cables, routers and to wireless
access points. - One Administrative Control
✓ Coverage: Limited to geographic area of Home
✓ Diagnosis: LAN Network
✓ Using: Wireless circuits - Diagnosis: WLAN Network
BACKBONE Network
Now, what happens when a single LAN isn't enough? Imagine a university with separate
LANs for the library, the engineering building, and the dormitories. These LANs need to talk
to each other. We connect them using a Backbone Network (BN). Think of the BN as the
"network of networks," the central infrastructure that ties all the LANs together. It's a high-
speed network designed to carry a massive amount of aggregated traffic. It might span a
campus or a large corporate park
BackBone Lecture
Cafeteria Library
Network Halls
Single Lan Network
Single Lan Network
Nework that is binding all
the Single LAN networks Single Lan Network
together allowing
communication.
