Have you heard about the “Application layer and it’s protocols”

Through this article I hope to share a knowledge on the Application layer of the OSI model with the relevant protocols. Hope you will be able to gain a clear understanding of Application layer via this.

The Open System Interconnection model is a conceptual framework which is used to describe the functionalities of a computer networking system. Basically it further describes how the relevant information from a software application in one computer moves through a physical medium to the software application in another computer.

This OSI model is consisted with seven layers with different kinds of aspects.

When we take the above mentioned layers we can see different kinds of services that they are offering to the users. Among them I would like to share more knowledge on Application protocols which is consisted in the seventh layer : Application layer of of this OSI model.

Application layer

Basically application layer is having mainly three functions. They are,

1.Identifying communication partner

2.Determining resource availability

3.Synchronizing communication

Moreover this application layer is consisted with two layers called,

1. Client server architecture

An application program running on the local machine sends a request to another application program is known as a client, and a program that serves a request is known as a server. For example, when a web server receives a request from the client host, it responds to the request to the client host

1. peer to peer architecture

It has no dedicated server in a data center. The peers are the computers which are not owned by the service provider. Most of the peers reside in the homes, offices, schools, and universities etc. The peers communicate with each other without passing the information through a dedicated server, and this is called as peer-to-peer architecture. The applications are based on P2P architecture includes file sharing and internet telephony.

Next we will talk about the Application protocols. Basically we have FTP, Telnet , SMTP, SNMP and HTTP.

FTP

• FTP stands for File transfer protocol. FTP is a standard internet protocol provided by TCP/IP used for transmitting the files from one host to another. It is mainly used for transferring the web page files from their creator to the computer which acts as a server for other computers on the internet. it is used for downloading the files to computer from other servers. As the objectives it provides the method of sharing files, encouraging the use of remote computers, transfers the data efficiently.

TELNET

A terminal emulation that enables a user to connect to a remote host or device using a telnet client, usually over port 23.Telnet is one of the simplest ways to exchange data between two computers. It allows two computers anywhere on a computer network, including the worldwide Internet, to exchange text and other data in real time.

SMTP

SMTP defines the Simple Mail Transfer Protocol. SMTP is a set of communication guidelines that allow software to transmit an electronic mail over the internet is called Simple Mail Transfer Protocol. It provides a mail exchange between users on the same or different computers, and it also supports:

• It can send a single message to one or more recipients.
• Sending message can include text, voice, video or graphics.
• It can also send the messages on networks outside the internet.

The main purpose of SMTP is used to set up communication rules between servers.

SNMP

Simply SNMP is the Simple Network Management Protocol. There the SNMP framework is using for managing the devices on the internet. Basically it provides a set of operations for monitoring and managing the internet. You can see the process happening in there through the following picture.

HTTP

HTTP defines the Hyper Text Transfer Protocol. It is used to access the data on the World Wide Web. The HTTP protocol can be used to transfer the data in the form of plain text, hypertext, audio, video, and so on. This protocol is known as Hyper Text Transfer Protocol because of its efficiency that allows us to use in a hypertext environment where there are rapid jumps from one document to another document.

In this article I introduced the OSI model and it’s seventh layer called the Application layer. Then I was able to share more knowledge on that layer and how it’s protocols are working. Hope everyone had an interesting reading there.

Thank you.