Question

What are the five layers in the internet protocol stack? What are the principal responsibilities of each of these lay?

Answer 1

Solution:

The five Layers in Internet protocol stack are:

1.Application Layer  

2.Transport Layer  

3.Network Layer  

4.Link Layer  

5.Physical Layer  

The principal responsibilities of these layers are as follows:

1.Application Layer •Applications with appropriate requirement for user.  

•It is reserved for network applications and their application protocols such as HTTP, SMTP, and FTP etc.  

•Its protocol uses transport layer protocols for establishing host-to-host connection.  

2.Transport Layer  

•It is responsible for End-to-Communication  

•Transport layer transports messages from application layer between client and server of application  

•It uses two protocol for transporting messages: TCP and UDP.TCP provides reliable connection oriented services, while UDP provides connectionless service  

3.Network Layer  

•Network Layer moves packets from one host to destination.

•It has two principal component:IP protocol:-It defines the datagrams and decide how the end system and router will work Routing protocols: these protocols decide the routing path between source and destination. 4.Link Layer  

•It is responsible for link-level communication  

•Link layer receives the data gram from network layer at each node and delivers it to next node, the next node passes the datagram to network layer.so This layer moves entire frames from one network element to adjacent one.

•The service provided by link layer is protocol dependent

5.Physical Layer  

•It provides Physical media

•At each node, it moves individual bits of frames to next node.