OSI L1-7 QA

Question 1

TCP/IP model does not have ______ layer but OSI model have this layer.

a) session layer
b) transport layer
c) application layer
d) network layer

Answer 1

Answer: a) session layer
Explanation: In OSI reference model, there are two layers which are not present in TCP/IP model. They are Presentation and Session layer. The functions of Presentation and Session layer in the OSI model are handled by the transport layer itself in TCP/IP.

Question 2

TCP/IP model was developed _____ the OSI model.

a) prior to
b) after
c) simultaneous to
d) with no link to

Answer 2

Answer: a) prior to
Explanation: Several TCP/IP prototypes were developed at multiple research centers between 1978 and 1983, whereas OSI reference model was developed in the year 1984. TCP/IP was developed with the intention to create a model for the Internet while OSI was intended to be a general network model.

Question 3

Which layer provides the services to user?

a) application layer
b) session layer
c) presentation layer
d) physical layer

Answer 3

Answer: a) application layer
Explanation: In networking, a user mainly interacts with application layer to create and send information to other computer or network. Application layer provides the interface between applications and the network. It is the top-most layer in both the TCP/IP and the OSI model.

Question 4

The OSI reference model is a seven-layer reference model that originated from the

a) ISO standards committee
b) ITU standards committee
c) IEEE standards committee
d) ANSI standards committee

Answer 4

Answer : a) ISO - International Standards Organization

Question 5

Which layers of the OSI model are referenced in the 802.11 standard? (choose two)

a) Application
b) Data-Link
c) Presentation
d) Physical
e) Transport
f) Network

Answer 5

Answer : b) Data-Link

Question 6

Which layer of the OSI model converts packets into electrical or optical signals for sending on the transmission media ?

a) Application
b) Presentation
c) Physical
d) Session

Answer 6

Answer : c) Physical

Question 7

Which layer provides error detection?

a) Application
b) Session
c) Transport
d) Datalink

Answer 7

Answer d) Datalink

Logical Link control sub layer provides error detection using Frame check sequence

Question 8

What are the responsibilities of Transport Layer?

Answer 8

• Multiplexing and De-Multiplexing.
• Segmentation and Re-assembly.
• Flow Control.
• Error Correction.
• Connection Establishment.
• Sequencing.
• Acknowledgement.
• 3 way Handshake.

Question 9

What are the responsibility of Datalink layer?

Answer 9

Framing,
Error detection,
CRC and
Physical Addressing is the task of DLL

Question 10

• What is the function of the Application Layer in networking ?

Answer 10

Application Layer is responsible for providing a user interface in between user and Network with the help of applications like web browsers

Question 11

• In which layer term “Frames” is used ?

Answer 11

Frames are PDU of Data Link Layer

Question 12

• In which layer term “Packets” is used ?

Answer 12

Packets are PDU of Network Layer

Question 13

• In which layer term “Segments” is used ?

Answer 13

Segments are used at Transport Layer

Question 14

• Give some example for protocols work at Application layer ?

Answer 14

Application Layer Protocols are HTTP, HTTPs, Telnet, SSH, DNS, FTP, TFTP, DHCP, RIP

Question 15

• Which layer provides logical addressing that routers will use for path determination ?

Answer 15

Network Layer

Question 16

Which layer combines bits into bytes and bytes into frames, uses MAC addressing, and provide error detection ?

Answer 16

Data Link Layer

Question 17

Which layer specifies voltage, wire speed, and pinout cables and moves bits between devices ?

Answer 17

Physical Layer

Question 18

How Data breaks down on each layer from top to bottom ?

Answer 18

Encapsulation occurs in following format

Question 19

Which layer defines how data is formatted, presented, encoded,and converted for use on the network ?

Answer 19

Presentation Layer

Question 20

Which layer is responsible for creating, managing and terminating sessions between applications ?

Answer 20

Session Layer

Question 21

What are the different network typologies in Physical layer ?

Answer 21

Mesh
Star/Hub & Spoke
Ring
Bus
Hybrid

Question 22

Which layer provides the rules for framing, converting electrical signals to data, error checking, physical and media access control (MAC) addressing

Answer 22

Data Link Layer

Question 23

What are 2 sub layers of Data Link Layer

Answer 23

1. Logical Link Control

2. Media Access control

Question 24

What are the Data Link Layer protocols ?

Answer 24

1. Ethernet
2. Token Ring
3. FDDI
4. IEEE 802.3
5. IEEE 802.11

Question 25

In which layer MAC address decides where to forward frames ?

Answer 25

Data Link Layer

Question 26

IP of TCP/IP, ARP protocol is example of which layer ?

Answer 26

Network Layer

Question 27

IPv4

Answer 27

• Uses ARP
• 32-bit address in quad-dotted from
• close to 4.3 billion addresses

Question 28

IPv6

Answer 28

• Uses Neighbor Solicitation instead of ARP
• 128 bit address in 8 groups of 4 hexa decimals
• 3.4 undecillion addresses

Question 29

Which layer provides transparent transfer of data between end system or hosts and is responsible for end-to-end error recovery and flow control

Answer 29

Transport Layer

Question 30

Which layer is a persistent logical linking of two software application processes

Answer 30

Session layer

Question 31

Which layer deals with data format conversion and possibly with encryption and security

Answer 31

Presentation layer

Question 32

Which layer responsible for delivering and formatting of information application layer for further processing or display

Answer 32

Presentation layer

Question 33

Which layer interacts with software application that implement a communicating component

Answer 33

Application Layer

Question 34

Gateway is which layer device

Answer 34

Layer 7 Application Layer