Question

1- Definition and introduction of its layer
2- Explain the network functions
3- Explain the data transfer method in the network
4- Mention the protocols if there is and explain them
5- Network positives and negatives effect

for

physical layer

data link layer

network layer

transport layer

presentation layer

application layer

and the tcp/ip

Answer 1

ANSWER :

ANS 1. PHYSICAL LAYER :

-- Definition and Introduction : The Physical layer is the lowest layer of the OSI model . It transfer the unstructured data in the form of bits. The Physical resources are used here i.e. router , switch etc.

-- Network Functions : It deals with the physical connectivity of the stations. It describes the wiring, cabling,pulses etc. It also provides the functions to the above layer i.e. data link layer.

  -- Data transfer Method : The data is transferred in the form of unstructured bits in this layer.

-- Protocol used here : The protocols used in this layer is Ethernet. It is a protocol mostly used in LAN and in this the data is transferred in the from of frames.

-- Positive and Negative : Positive - The speed is very fast upto 54Mbps. It is flexible and secure.

Negative - It can be costly. Cumbersome specification of the protocols.

2. DATA LINK LAYER :

-- Definition and Introduction : It is the second layer of the OSI model . It is also called as protocol layer. the data bits received by physcial layer are encoded as well as decoded.

--Network Functions : It performs function of encoding and decoding the bits and converting into the frames. It also tells as how the device should recover from the collision if it occurs.

-- Data transfer Method : The data is transferred in the form of Frames.

-- Protocol used here : There are many protocols i.e. LAP , LCP , HDLC , PPP. The LAP ( Link access protocol ) is used to transfer data and make frames. The LCP ( Link Control Protocol ) It provides HDLC services on LAN , it is used for configuring and testing the data frames.

-- Positive and Negative : Positive - Error detection as well as correction. There is status induction. Connection oriented.

Neagtive - Sometimes the protocol used here can lead to the improper transfer of the packets.

3. NETWORK LAYER :

-- Definition and Introduction : It is the 3rd layer of OSI model. It is responsible for routing forwarding. The basic setting up of a network between both is done here.

--Network Functions : It does routing. It does encryption. Sends the data between different Devices

-- Data transfer Method : In ths the data is transferred in the form of Packets.

-- Protocol used here : The main protocol used is IP ( Internet Protocol ) , ICMP ( Internet control message protocol ). The IP provides routing to the packets and ensures delivery of packets . ICMP is used to correct the issues that can come in the network.

-- Positive and Negative : Positive - It does routing. It does encryption. Sends the data between different Devices

4. TRANSPORT LAYER :

  

-- Definition and Introduction : It is the 4th layer of the OSI model. It provides the end to end communication. It has layerd architecture.

--Network Functions : It provides end to end communication. It provides flow control as well as the Traffic control.

-- Data transfer Method : The data is transfered in the form of Mesaage or Packets .

-- Protocol used here : TCP protocol is used . TCP ( Transmission control protocol) is the one which provides the end to end delivery of the message.

-- Positive and Negative : Positive : It provides end to end communication. It provides flow control as well as the Traffic control.

5.PRESENTATION LAYER :

  

-- Definition and Introduction : It is the 6th layer of the OSI model. It present the data in the well defined format that is neccessary and useful. It is also called syntax layer.

--Network Functions : It provides the properly defined and a standard as well as accurate format. It provides data encryption, compression and Handling of the graphics.

-- Data transfer Method : The data is transferred in the form of Packets.

-- Protocol used here : The protocol used is FTP. The FTP is the file transfer protocol that is used to send files over the internet

-- Positive and Negative : Positive - It provides the properly defined and a standard as well as accurate format. It provides data encryption, compression and Handling of the graphics.

6. APPLICATION LAYER :

  

-- Definition and Introduction : It is the 7th layer of the OSI model. It uses abstraction.

--Network Functions : It mention sthe communication protocols and also the interface methods. It uses SMTP to ensures the mail delivery.

-- Data transfer Method : The data is transferred in the form of packets.

-- Protocol used here : The protocols used are SMTP , POP , HTTP . The SMTP ensures the best transfer of mail over the netwrok and the HHTP ( hyper text transfer protocol ) transfers the text over anetwork.

-- Positive and Negative : Positive - : It mention sthe communication protocols and also the interface methods. It uses SMTP to ensures the mail delivery.

7. TCP/IP :

-- Definition and Introduction : TCP/IP the transmission control protocol/ internet protocol . It is a communication protocol, used to communicate among nternet.

--Network Functions : It provides benifits like - The IP moves the packets and TCP is responsible to check the safe delivery of packets at the destination.

-- Data transfer Method : data is transferred in the form of packets.

-- Protocol used here : TCP/IP is the protocol in itself

-- Positive and Negative : Positive - Provides the delivery of packets and also ensures that the data is transferred safely and in a particular order.

Negative - It is not generic in nature. It vaguely seprates the protocols, interfaces and services.