Explain the function of each layer of OSI reference model with neat diagram.

Explain the function of each layer of OSI reference model with neat diagram.
by

1 Answer

Answer :

OSI model (open system interconnection) model was developed by ISO (international standard organization)

Function of OSI model:

i. It provides way to understand how internetwork operates.

ii. It gives guideline for creating network standard.

OSI model has 7 layers as shown in the figure.


Application Layer 
Presentation Layer 
Session Layer
Transport Layer 
Network Layer
Data link Layer 
Physical Layer 


OSI model has following 7 layers as Physical layer, data link layer, Network layer, Transport layer, session layer, presentation layer, application layer.

1. Physical layer: It co-ordinates the functions required to transmit bit stream over physical medium. It deals with mechanical and electrical specifications of interface and transmission medium. For transmission it defines procedures and functions that devices and transmission medium has to perform


Physical characteristics of interfaces and media.

Representation of bits: Data rate(transmission rate).

Synchronization of bits.

Line configuration: Point to point or multipoint configuration should be used.

2. Data link layer: It is responsible for transmitting group of bits between the adjacent nodes.

The group of bits is called as frame. The network layer passes a data unit to the data link layer. Header and trailer is added to the data unit by data link layer. This data unit is passed to the physical layer. Data link layer is responsible for moving frames from one node to the next. 


Functions of data link layer are:

1) Framing

2) Physical addressing

3) Flow control

4) Error control

5) Media access control

6) Node to node delivery

3. Network layer: It is responsible for routing the packets within the subnet i.e. from source to destination. It is responsible for source e to destination delivery of individual packets across multiple networks. It ensures that packet is delivered from point of origin to destination.

Functions of network layer:

1) logical addressing

2) Routing.

3) Congestion control

4) Accounting and billing

5) Address transformation

6) Source host to destination host error free delivery of packet.

4. Transport layer: Responsibility of process to process delivery of message Ensure that whole message arrives in order.

Functions of Transport layer:

1) Service point addressing

2) Segmentation and reassembly

3) Connection control

4) Flow control: Flow control is performed end to end 5) Error control

5. Session layer: Establishes, maintains, and synchronizes the interaction among communication systems It is responsible for dialog control and synchronization.

Functionsof Session layer:

1) Dialog control

2) Synchronization, session and sub session

3) Session closure

6. Presentation layer: It is concerned with syntax, semantics of information exchanged between the two systems.

Functions of Presentation layer:

Translation: presentation layer is responsible for converting various formats into required format of the recipient

Encryption: Data encryption and decryption is done by presentation layer for security.

Compression and Decompression: data to be transform compressed while sending and decompress while receiving for reducing time of transmission.

7. Application layer: It enables user to access the network. It provides user interfaces and support for services like email, remote file access.

Functions of Application layer:

Network virtual terminal

file transfer access and management

mail services and directory services

by

Related questions

Why layered architecture is used in OSI reference model? Discuss.

Description : Why layered architecture is used in OSI reference model? Discuss.

Last Answer : The OSI reference model is as shown in the figure.There are seven layers in the model. Physical layer, Data link layer, Network layer, Transport layer, Session layer, Presentation layer, ... the entire package is converted to a form that can be transferred to the receiving machine. 

The............ layer of OSI model can use the trailer of the frame for error detection. A) Physical B) Data link C) Transport D) Presentation

Description : The............ layer of OSI model can use the trailer of the frame for error detection. A) Physical B) Data link C) Transport D) Presentation

Last Answer : A) Physical

The layer one of the OSI model is A) Physical layer B) Link layer C) Router layer D) Broadcast layer

Description : The layer one of the OSI model is A) Physical layer B) Link layer C) Router layer D) Broadcast layer

Last Answer : A) Physical layer

Which of the following OSI layers correspond to TCP/IP's application layer? A) Application B) IP Address C) Session D) All of the above

Description : Which of the following OSI layers correspond to TCP/IP's application layer? A) Application B) IP Address C) Session D) All of the above

Last Answer : D) All of the above

TCP/IP ..................layer corresponds to the OSI models to three layers. A) Application B) Presentation C) Session D) Transport

Description : TCP/IP ..................layer corresponds to the OSI models to three layers. A) Application B) Presentation C) Session D) Transport

Last Answer : A) UDP

Find out the OSI layer, which performs token management. A) Network Layer B) Transport Layer C) Session Layer D) Presentation Layer

Description : Find out the OSI layer, which performs token management. A) Network Layer B) Transport Layer C) Session Layer D) Presentation Layer

Last Answer : C) Session Layer

Explain Satellite communication with neat diagram

Description : Explain Satellite communication with neat diagram

Last Answer : SATELLITE COMMUNICATION: In satellite communication, signal transferring between the sender and receiver is done with the help of satellite. In this process, the signal which is basically a beam ... of satellite: Satellite television digital cinema satellite radio satellite internet access

Explain the services provided by transport layer in TCP/IP model.

Description : Explain the services provided by transport layer in TCP/IP model.

Last Answer : Responsibility of process to process delivery of message Ensure that whole message arrives in order. 1. Service point addressing: -several programs run at a time on computer. Delivery is ... transport layer without error(damage or loss or duplication). Error correction is done by retransmission.

In which OSI layers does the FDDI protocol operate? A) Physical B) Data link C) Network D) A and B

Description : In which OSI layers does the FDDI protocol operate? A) Physical B) Data link C) Network D) A and B

Last Answer : D) A and B

Which layers of the OSI determines the interface often system with the user? A) Network B) Application C) Data link D) Session

Description : Which layers of the OSI determines the interface often system with the user? A) Network B) Application C) Data link D) Session

Last Answer : B) Application

Write the name of layers that perform the following functions in OSI : I. Data Encryption II. Error Correction III. File Transfer IV. Data Encoding

Description : Write the name of layers that perform the following functions in OSI : I. Data Encryption II. Error Correction III. File Transfer IV. Data Encoding

Last Answer : 1. Data Encryption-Presentation Layer 2. Error Correction-Data link layer and Transport layer 3. File Transfer-Application layer 4. Data Encoding-Presentation layer

Give function of each layer of OSI reference model.

Description : Give function of each layer of OSI reference model.

Last Answer : OSI model (open system interconnection) model was developed by ISO (international standard organization)  Function of OSI model: i. It provides way to understand how internetwork operates. ... virtual terminal file transfer access and management mail services and directory services

Which is the main function of transport layer?

Description : Which is the main function of transport layer?

Last Answer : B) End to end delivery

The physical address to each machine is provided by which layer in an OSI reference model? A. Physical layer B. Data Link Layer C. Network Layer D. Transport Layer

Description : The physical address to each machine is provided by which layer in an OSI reference model? A. Physical layer B. Data Link Layer C. Network Layer D. Transport Layer

Last Answer : B. Data Link Layer

The physical address to each machine is provided by which layer in an OSI reference model? A. Physical layer B. Data Link Layer C. Network Layer D. Transport Layer

Description : The physical address to each machine is provided by which layer in an OSI reference model? A. Physical layer B. Data Link Layer C. Network Layer D. Transport Layer

Last Answer : B. Data Link Layer

Explain the architecture of Bluetooth technology with suitable diagram.

Description : Explain the architecture of Bluetooth technology with suitable diagram.

Last Answer : Bluetooth is short range wireless technology. Range of Bluetooth is 10 meters. Bluetooth Architecture defines 2 types of networks. 1)Piconet 2)Scatternet Piconet: - It is a Bluetooth network that ... . This node is called bridge slave. This node cannot be the master of two piconets.

Explain PAN with suitable diagram. Differentiate between PAN and CAN.

Description : Explain PAN with suitable diagram. Differentiate between PAN and CAN.

Last Answer : A personal area network(PAN) is a network organized around an individual person. A PAN can also be used for communication among personal devices themselves(interpersonal communication).PAN network can be ... used for personal communication. 4. CAN is mainly used for corporate campuses.

TELNET, FTP, SMTP, Protocols fall in the following layer of OSI reference model? a. Transport layer b. Internet layer c. Network layer d. Application layer

Description : TELNET, FTP, SMTP, Protocols fall in the following layer of OSI reference model? a. Transport layer b. Internet layer c. Network layer d. Application layer

Last Answer : d. Application layer

Which of the following layers of the OSI reference model is concerned with the syntax of data exchanged between application entities? a. Presentation layer b. Application layer c. Transportation layer d. Session layer

Description : Which of the following layers of the OSI reference model is concerned with the syntax of data exchanged between application entities? a. Presentation layer b. Application layer c. Transportation layer d. Session layer

Last Answer : a. Presentation layer

In the TCP/IP protocol architecture, the Network Access Layer includes ………………………………...layers of the OSI Reference Model. A. presentation, session, applicationB. physical, data link, network C. data link, network D. physical, data link

Description : In the TCP/IP protocol architecture, the Network Access Layer includes ………………………………...layers of the OSI Reference Model. A. presentation, session, application B. physical, data link, network C. data link, network D. physical, data link

Last Answer : B. physical, data link, network

Which layer of OSI reference model is responsible for decomposition of messages and generation of sequence numbers to ensure correct re-composition from end to end of the network? (A) Physical (B) Data-link (C) Transport (D) Application

Description : Which layer of OSI reference model is responsible for decomposition of messages and generation of sequence numbers to ensure correct re-composition from end to end of the network? (A) Physical (B) Data-link (C) Transport (D) Application

Last Answer : (C) Transport 

Discuss hybrid topology with suitable diagram.

Description : Discuss hybrid topology with suitable diagram. 

Last Answer : Discuss hybrid topology with suitable dig. Hybrid topology is one that uses two or more basic topologies together Fig.1 depicts this. In this case, the bus, star & ring topologies are used to ... many networks are quite complex but they can be reduced to some form of hybrid topology.

On the upper layer of SSL, a protocol for initial authentication and transfer of encryption keys, called the ………………… A) SSL handshake protocol B) SSL authentication protocol

Description : On the upper layer of SSL, a protocol for initial authentication and transfer of encryption keys, called the ………………… A) SSL handshake protocol B) SSL authentication protocol

Last Answer : A) SSL handshake protocol

At the lower layer of SSL, a protocol for transferring data using a variety of predefined cipher and authentication combinations called the ………………. A) SSL handshake protocol B) SSL authentication protocol C) SSL record protocol D) SSL cipher protocol

Description : At the lower layer of SSL, a protocol for transferring data using a variety of predefined cipher and authentication combinations called the ………………. A) SSL handshake protocol B) SSL authentication protocol C) SSL record protocol D) SSL cipher protocol

Last Answer : C) SSL record protocol

The most important and common protocols associated TCP/IP internetwork layer are. i) Internet Protocol (IP) ii) Internet Control Message Protocol (ICMP) iii) Bootstrap Protocol (BOOTP) iv) Dynamic Host Configuration Protocol (DHCP) V) Address Resolution Protocol (ARP) A) i, ii, iii, and iv only B) ii, iii, iv and v only C) i, iii, iv and v only D) All i, ii, iii, iv and v only

Description : The most important and common protocols associated TCP/IP internetwork layer are. i) Internet Protocol (IP) ii) Internet Control Message Protocol (ICMP) iii) Bootstrap Protocol (BOOTP) iv) Dynamic Host Configuration Protocol (DHCP) V) ... C) i, iii, iv and v only D) All i, ii, iii, iv and v only

Last Answer : D) All i, ii, iii, iv and v only

Which of the following is not the layer of TCP/IP protocol? A) Application Layer B) Session Layer C) Transport Layer D) Internetwork layer

Description : Which of the following is not the layer of TCP/IP protocol? A) Application Layer B) Session Layer C) Transport Layer D) Internetwork layer

Last Answer : B) Session Layer

The data unit in the TCP/IP layer called a ..... A) Message B) Segment C) Datagram D) Frame

Description : The data unit in the TCP/IP layer called a ..... A) Message B) Segment C) Datagram D) Frame

Last Answer : D) Frame

The name of the protocol which provides virtual terminal in TCP/IP model is. A) Telnet B) SMTP C) HTTP

Description : The name of the protocol which provides virtual terminal in TCP/IP model is. A) Telnet B) SMTP C) HTTP

Last Answer : A) Telnet

Explain connectionless and connection oriented protocol. Give the example for each type.

Description : Explain connectionless and connection oriented protocol. Give the example for each type.

Last Answer : Connection less protocol: These protocols do not establish a connection between devices. It is manually achieved by transmitting information in one direction, from source to destination without checking to ... SMTP establish a TCP connection between Sender And port number 25 of receiver

Give the name of protocols used by different layers of TCP/IP. Discuss the function of ARP and RARP.

Description : Give the name of protocols used by different layers of TCP/IP. Discuss the function of ARP and RARP.

Last Answer : TCP/IP Model contains following layer. 1) Host-to-Network Layer - It defines characteristics of transmission media. It also concern with delivery of data when two systems are attached to same network ... such broadcasts are not forwarded by routers, so a RARP server is needed on each network. 

Two unpedauces given by Z1 = 10 + j5 and Z2 = 8 + j9 are joined in parallel and connected across a voltage of V = 200 + j0. Calculate the circuit current and branch currents. Draw the vector diagram.

Description : Two unpedauces given by Z1 = 10 + j5 and Z2 = 8 + j9 are joined in parallel and connected across a voltage of V = 200 + j0. Calculate the circuit current and branch currents. Draw the vector diagram.

Last Answer : Solution: Given, Z1=10+j5, Z2=8+j9, V=200+j0

For R-C series circuit draw (i) Circuit diagram (ii) Vector diagram (iii) Waveform of voltage and current

Description : For R-C series circuit draw (i) Circuit diagram (ii) Vector diagram (iii) Waveform of voltage and current

Last Answer : i) Circuit diagram ii)Vector diagram iii)Waveform of voltage and current

In a................ topology, if there are n devices in a network, each device has n-1 ports for cables. A) Mesh B) Star C) Bus D) Ring

Description : In a................ topology, if there are n devices in a network, each device has n-1 ports for cables. A) Mesh B) Star C) Bus D) Ring

Last Answer : Mesh

What is the name of the network topology in which there are bi-directional links between each possible node? A) Ring B) Star C) Tree D) Mesh

Description : What is the name of the network topology in which there are bi-directional links between each possible node? A) Ring B) Star C) Tree D) Mesh

Last Answer : Mesh

The power flow problem mathematical model for a linear transmission network

Description : The power flow problem mathematical model for a linear transmission network (A) is non-linear (B) is linear (C) considers time variation of generation (D) does not consider tap-changing transformers

Last Answer : The power flow problem mathematical model for a linear transmission network is non-linear

Explain the seven layers of the OSI reference model.

Description : Explain the seven layers of the OSI reference model.

Last Answer : Below are the seven layers of the OSI reference model:  Physical Layer: This layer converts data bits into radio signals. An example of this is Ethernet.  Data Link layer: At data ... which both end user and application interact with. This layer provides services like email, file transfer, etc.

What is the main function of Session layer in OSI model? a. Defines how data is formatted between the devices b. Made physical connection between server and client c. Both a and b d. None of the above

Description : What is the main function of Session layer in OSI model? a. Defines how data is formatted between the devices b. Made physical connection between server and client c. Both a and b d. None of the above

Last Answer : a. Defines how data is formatted between the devices

List all seven layer of OSI model and describe function of application layer.

Description : List all seven layer of OSI model and describe function of application layer.

Last Answer : The layers of OSI model are as follows:  (1) The Physical Layer: This defines an interface in terms of the connections, voltage levels and data rate, in order for signals to ... with the applications programs needed. Examples include electronic mail, word processing, banking transactions, etc.  

Explain handoff procedure in mobile communication.

Description : Explain handoff procedure in mobile communication.

Last Answer : Assume that there is a call going on between two parties over a voice channel. When the mobile unit moves out of coverage area of a particular cell site the reception becomes weak. Then the cell ... arranges the handoff requests in a queue instead of rejecting them, if the new cell sites are busy.

Explain four features of computer networks.

Description : Explain four features of computer networks.

Last Answer : A computer network is interconnection of two or more computers connected to each other so that they can exchange information such as e-mail, messages or documents, or share resources such as disk storage or printer. ... Digital Network (ISDN). 4. Cable TV. 5. Digital Subscriber Line (DSL).

Explain following: I. Telnet II. FTP

Description : Explain following: I. Telnet II. FTP 

Last Answer : 1. Telnet: TELNET is abbreviation for Terminal Network. It is standard TCP/IP protocol for virtual terminal services proposed by ISO. TELNET enables establishment of connection to a remote system in such ... . FTP uses port 21 for the control connection and port 20 for the data connection. 

Explain different modes of fibre optic cable.

Description : Explain different modes of fibre optic cable.

Last Answer : Current technology supports two modes for propagating light along optical channels. 1. Multimode. 2. Single mode.  Multimode can be implemented in two form:  1. Step ... All the beams arrive at the destination together and can be recombined with little distortion to the signal.

Explain horizontal and vertical communication.

Description : Explain horizontal and vertical communication.

Last Answer : Horizontal communication Fig: Horizontal Communication in OSI Model. 1) The horizontal communication is the logical connection between the layers, there is no direct communication ... communication, it becomes protocol at each layer simultaneously. Fig:Vertical communication

Explain sub-netting and super-netting with example.

Description : Explain sub-netting and super-netting with example.

Last Answer : Sub-netting:subnet mask is a net mask with the only real difference being that breaking a larger network into smaller parts and each smaller section will use different sets of address ... address) AND 11111111.11111111.11111100.00000000 (supernet mask) Returns 11000000.10101000.01000000.00000000

Draw and explain fiber optic cable.

Description : Draw and explain fiber optic cable.

Last Answer : As shown in the figure, at the center is the glass core through which the light propagates. In multimode fibers, the core is typically 50 microns in diameter. In single mode fibers, the core is ... be fused to form a solid connection. A fusion splice is almost as good as a single drawn fiber.

Explain following protocols: I. PPP II. SLIP

Description : Explain following protocols: I. PPP II. SLIP

Last Answer : (i)PPP:-PPP means point to point protocol. It is a much more developed protocol than SLIP(which is why it is replacing it).It transfers additional data, better suited to data transmission over the ... character(the END character, the ASCII code of which is 192).A SLIP frame looks like:

Explain encapsulation with example.

Description : Explain encapsulation with example.

Last Answer : Each layer in the layered architecture provides service to the layers which are directly above and below it. The outgoing information will travel down through the layers to the lowest layer. While ... to each packet obtained from layer 3 and pass it to layer 1 for physical transmission. 

Explain infrared communication. List any two disadvantages of infrared communication.

Description : Explain infrared communication. List any two disadvantages of infrared communication.

Last Answer : Infrared communication (IR) is an example of wireless communication. However, it is limited to very simple applications & suffers from several disadvantages, mainly very small bandwidth & distances ... areas require multiple emitter panels, which will increase the cost of the system.

Draw and explain Co-axial cable.

Description : Draw and explain Co-axial cable.

Last Answer : Coaxial cable (also called as coax) has an inner central copper conductor surrounded by an insulating sheath, which in turn is enclosed in the metal mesh. This outer conductor (shield) acts not ... building where a number of twists and turns are required.  4. limited to size of network.

Each layer of the OSI model receives services or data from a layer. a. none b. below and above layer both c. above layer d. below layer

Description : Each layer of the OSI model receives services or data from a layer. a. none b. below and above layer both c. above layer d. below layer

Last Answer : d. below layer