CH3

Question 1

The OSI Model has _____ layers?

Answer 1

7

Question 2

Write down a mnemonic you use to remember the OSI Model?

Answer 2

All People Seem To Need Data Protection

Application + Presentation + Session + Transport + Network + DataLink + Physical

Question 3

TCP is Connection-Less Protocol?

True
False

Answer 3

False

TCP is a Connection-Oriented Protocol.
UDP is a Connection-Less

Question 4

What is a unit of data called at the Transport Layer?

Packet
Segment
Frame
Protocol Datat Unit (PDU)

Answer 4

Segment

Question 5

Which of the following could be a valid MAC Address for a Server named Server 1?

Server1
192.168.1.5
A4-BA-10B-FA-60-AD
G4-BA-10B-FA-60-AT

Answer 5

A4-BA-DB-FA-60-AD

Media Access Control (MAC) address, or physical address, is composed of 6 pairs of hexadecimal characters.
Valid hexadecimal characters are from 0 to 9 and A to F.

Question 6

IPv4 operates on the _____ layer of the OSI Model?

Answer 6

Network

Both IPv4 and IPv6 operate in the Network Layer.

Question 7

List the protocols that operate on the Transport Layer of the OSI Model?

Answer 7

TCP and UDP

Several other Transport Layer protocols exist.

Question 8

Devices that operate on layer 7 of the OSI Model are more intelligent than devices that operate on layer 1?

True
False

Answer 8

True

Devices such as Hubs on Layer 1 have very little intelligence.
Devices such as Advanced Firewallls on Layer 7 have much more intelligence.

Question 9

Routers operate on which of the following layers of the OSI Model?

Layer 1
Layer 2
Layer 3
Layer 4
NONE of the Above

Answer 9

Layer 3

Routers operate on the Network layer - Layer 3.

Question 10

Proxy Servers operate on which of the following layers of the OSI Model?

Layer 1
Layer 2
Layer 3
Layer 4
NONE of the Above

Answer 10

None of the Above

Proxy Servers operate on the Application Layer, Layer 7 of the OSI Model.

Question 11

OSI Model - Layer 3?

Answer 11

Network (Need)

Decides which physical path the data will take. 
Responsible for routing the data packet based on it's logical IP Address 
Fragments and reassembles the packets 
Instructs data on how to find it's ultimate destination.

Question 12

OSI Model - Layer 7?

Answer 12

Application (All)

Human Computer Interaction layer, where applications can access the network services. 
Manages communications between Applications 
Supports Application protocols such as Email, HTTP, and FTP 
At this Layer, Data still resembles something People can Read.

Question 13

OSI Model - Layer 2?

Answer 13

Data Link (Data)

Defines the format of data on the network 
Responsible for sending data to the physical layer. 
Data packets are encoded and decoded into bits 
Handles flow control and frame synchronization. 
Divided into 2 sub lyers --- MAC (Media Access Control) and the LLC (Logical Link Control) layer.

Question 14

OSI Model - Layer 1?

Answer 14

Physical (Protection)

Transmits raw bit stream over the physical medium. 
Defines the network standards and physical characteristics of a network such as connectors, media type's, cables, voltages. 
Defines the Topology of a Network.

Question 15

OSI Model - Layer 4?

Answer 15

Transport (To)

Transmits data using transmission protocols including TCP and UDP 
Provides the transfer of Data between End Users 
Responsible for resending any packets that do not receive an acknowledgement from the destination. 
This layer can guarantee that packets are received.

Question 16

OSI Model - Layer 6?

Answer 16

Presentation (People)

Ensure that data is  in a usable format and is where data encryption occurs. 
This layer is where data is first converted into a form that can be sent over a Network. 
Data is Compressed and Decompressed and Encrypted or Decrypted. 
Sometimes referred to as the Translation Layer.

Question 17

OSI Model - Layer 5?

Answer 17

Session (Seem)

Maintains connections and is responsible for controlling ports and sessions. 
Controls the dialog during communications. 
Establishes, manages and terminates the connections between the local and remote application. 
Known as the "Traffic Cop" because it directs network traffic.