Lesson 4 - Session, Presentation and Application Layers

Question 1

Which Layer controls the communications from one endpoint to another.

Answer 1

Session layer

Question 2

Name 3 Common Layer 5 modes of communicating

Answer 2

Full Duplex - Phone Communications
Half Duplex - two way radios
Simplex - Source can only send. Destination cannot respond

Question 3

Name some common Layer 5 Protocols

Answer 3

H.2254
L2TP
NetBIOS
RPC
SMB
SOCKs

Question 4

What main purpose of Presentation Layer (6)

Answer 4

Responsible for formatting and coding Application Layer data into a form that is acceptable for transmitting on the network

Question 5

Which Layer would be responsible for formatting and encrypting of data

Answer 5

Presentation Layer

Question 6

Name Some Common Protocols at the Presentation Layer

Answer 6

IMAP - Email
SSH - Secure Shell - cryptographic protocol
SSL - Secure Sockets Layer
TLS - successor to SSL - Transport Layer Security

Question 7

Besides Encryption and Formatting what is another key function

Answer 7

Converting data into standard formats for application program use such as:
ASCII, ETCDIC, TIFF, JPEG, GIF, etc

Question 8

Which layer only interacts directly with Human Beings

Answer 8

Layer 7 Application using User Interface

Question 9

Name common Layer 7 Protocols

Answer 9

DHCP
FTP
HTTP
NFS
SMTP
SIP
SNMP
Telnet

Question 10

True or False a Word Processor operates at Layer 7

Answer 10

False - that is not the type of application that this level is referring to

Question 11

Which Port does HTTPS Use

Answer 11

443
Bonus - is aTCP Protocol

Question 12

Which Port does FTP Use

Answer 12

20 and 21

Question 13

Which Port does SMTP Use

Answer 13

25
Bonus - Is a UDP Protocol

Question 14

Which Port Does Telnet Use

Answer 14

23

Question 15

What Service does Port 80 Use

Answer 15

HTTP

Question 16

Which Service does Port 53 Use

Answer 16

DNS

Question 17

Which Services does Port 69 Use

Answer 17

Trivial File Transfer Protocol (TFTP)

Question 18

Name the Most Common Application Architectures

Answer 18

Host-Based
Client-Based
Client/Server
Cloud Computing
Peer to Peer

Question 19

What was the main pitfall for Client Based (Diskless) Applications

Answer 19

Saturation of network

Question 20

What is the term for multiple appServers

Answer 20

N-tier

Question 21

What is the rapidly emerging use case for untrusted P2P applications

Answer 21

Blockchain

Question 22

What is an instance of a service listening for traffic on a specific port called

Answer 22

Socket

Question 23

Where did what we call the Internet originate from

Answer 23

DOD used a network called ARPANET for research. Educational institutions and then Large Corp started using it.

Question 24

In 1989 what English Computer Scientist proposed a novel way to connect resources across the Internt

Answer 24

Tim Berner-Lee created World Wide Web and created a new protocol called the Browser in 1991

Question 25

What Technique does today’s mobile and distributed apps use

Answer 25

Representational State Transfer (REST)

Question 26

What is the data at each of the layers of the OSI model called

Answer 26

Protocol Data Unit (PDU)

Question 27

What are the PDU Data called at each of the layers

Answer 27

App/Pres/Session - Data
Transport - Segments
Network - Packets
Data Link - Frames
Physical - Bits 1’s and 0’s

Question 28

Which ports are listening for DHCP

Answer 28

UDP 67 for Servers
UDP 68 for Workstations

Question 29

Netbios, SOCKS, RPC, SMB are protocols at what layer

Answer 29

Session
Application environments that use remote procedure calls commonly operate using Layer 5

Question 30

SNMP uses what ports to operate and what is the current version

Answer 30

Ports 161/162
SNMP version 3 which offers security such as authentication and encryption

Question 31

Compare a Worm vs Virus

Answer 31

Worms are self replicating that insert copies of themselves into executable codes, programs or documents and replicate faster than viruses.

Question 32

Which Service uses Port 179

Answer 32

BGP

Question 33

Kerberos uses what Port

Answer 33

88