Compare the layers of the OSI and TCP/IP models

Question 1

Name the 7 Layers of the OSI Model in the proper order

Answer 1

Layer 1 – Physical  
Layer 2 – Data link 
Layer 3 – Network 
Layer 4 – Transport 
Layer 5 – Session 
Layer 6 – Presentation 
Layer 7 – Application

Question 2

What is the Physical Layer responsible for?

Answer 2

Identifies the Network’s physical characteristics such as Hardware Devices and Network Topology

Question 3

Name the Device associated with the Physical Layer?

Answer 3

Repeaters,
Hubs,
Network Interface cards (NICs),
Cables and Connectors.

Question 4

What is the Data Link Layer responsible for?

Answer 4

The Data Link Layer is also responsible for logical link control, media access control, hardware addressing, error detection and handling and defining physical layer standards.
It provides reliable data transfer by transmitting packets with the necessary synchronization, error control and flow control.

Question 5

The Data Link Layer is divided into What to sublayers?

Answer 5

Media Access Control (MAC)

Logical Link Control (LLC)

Question 6

What is Media Access Control (MAC)

Answer 6

Controls how computers on the network gain access to the data and obtain permission to transmit it

Question 7

What is Logical Link Control (LLC)

Answer 7

Controls packet synchronization, flow control and error checking.

Question 8

What is the Network Layer responsible for?

Answer 8

This layer provides switching and routing technologies, creating logical paths, known as virtual circuits, for transmitting data from node to node. Routing and forwarding are functions of this layer, as well as addressing, internetworking, error handling, congestion control and packet sequencing.

Question 9

What is the Transport Layer responsible for?

Answer 9

It is responsible for maintaining reliable end-to-end communications across the network. It provides full-duplex virtual circuits on which delivery is reliable, error free, sequenced, and duplicate free.

Question 10

What are some of the protocols that operate at the Transport Layer?

Answer 10

TCP (transmission control protocol)
UDP (user datagram protocol)
RTP (real-time transport protocol)
SCTP (stream control transmission protocol).

Question 11

What is the Session Layer responsible for?

Answer 11

It establishes, manages (including providing security) and terminates connections between applications at each end.

Question 12

What are some of the protocols that operate at the Session Layer?

Answer 12

DLC (data link control)
PAP (printer access control), 
SMB (server message block), 
ASP (AppleTalk session protocol), 
NetBIOS (network basic input/output system) 
ZIP (zone information protocol).

Question 13

The Session Layer protocols are useful mainly in what type of applicaions?

Answer 13

multimedia applications for which it is necessary to coordinate the timing of two or more types of data, such as voice and moving images, with a high degree of precision. Examples include video conferencing and streaming

Question 14

What is the Presentation Layer responsible for?

Answer 14

It translates data from programs and protocols in the application layer above it to formats that can be transmitted over networks and used by other applications on other hosts. It is also responsible for the delivery and formatting of information to the application layer for further processing or display.

Question 15

What are some of the protocols that operate at the Pesentation Layer?

Answer 15

ASCII (American standard code for information interchange),
EBCDIC (extended binary coded decimal interchange code),
MIDI (musical instrument digital interface),
MPEG (moving picture experts group), SSL (secure sockets layer),
TDI (tabbed document interface),
TLS (transport layer security)
XDR (external data representation).

Question 16

What is the Applicatioin Layer responsible for?

Answer 16

It provides services to connect application programs to communications protocols and to ensure effective communication with other application programs over a network.

Question 17

What are the services that are provided at the Application Layer?

Answer 17

• confirming that necessary communication resources exist (e.g., that there a functioning modem in the sender’s computer)
• ensuring identification of the destination host
• authenticating either or both the message sender and recipient
• determining protocol rules at the application level
• ensuring agreement at both ends about error recovery procedures, data integrity and privacy.

Question 18

What are some of the protocols that operate at the Application Layer?

Answer 18

DHCP (dynamic host configuration protocol)
FTP (file transfer protocol)
HTML (hypertext markup language)
HTTP (hypertext transfer protocol)
IRC (Internet relay chat) 
NFS (network file system) 
NNTP (network news transfer Protocol)
POP3 (post office protocol 3), 
SMTP (simple mail transfer protocol)
SNMP (simple network management protocol) Telnet