What is Tcp/ip

This is one of the most common types of protocol used to transfer data, TCP/IP includes a number of different protocols which are used to govern the communication between various devices. TCP/IP is split into two parts: the transmission control protocol and the internet protocol. TCP deals with the communications happening between the different applications running on a computer. For instance, when the browser is trying to connect with a webpage, it will communicate with the OS.

The OS will then communicate with the Network Interface Card’s driver to get it to retrieve the required information. The application layer within TCP/IP has numerous different protocols of its own. These are used by software applications which are utilized by normal users to establish the connection rules between the piece of software being used by the user and the server. This ensures that the client’s data is being sent and received correctly by the application as it is following a set of rules. For instance, if a data packet was corrupted during transfer, the error checking specified by the protocol would pick this up. That data packet would then be resent as a fresh copy.

There are numerous different protocols which the application layer can use. Which one is used would depend on the type of information being transferred by the application. Examples of application layer protocols include:

• HTTP – This protocol is used for transmitting standard webpages between the server and the client. This is the main protocol used to distribute information and data across the World Wide Web.
• HTTPS – This protocol is similar to HTTP. However, there are additional steps as data sent over HTTPS must be encrypted, therefore the devices need to swap encryption keys before transmission can start. This is usually used for financial transactions such as online banking and e-Commerce.
• SMTP – SMTP stands for Simple Mail Transfer Protocol and is used to send email messages from one server to another over the internet. However, SMTP has very limited capacity to queue incoming emails, therefore SMTP is used for outgoing mail and either POP3 or IMAP will be used for incoming emails.
• POP 3 – This is a protocol which is used to retrieve emails from a mail server. POP3 is usually used by desktop mail clients to connect to the user’s mail server and retrieve the messages stored on it. The software can then display the emails to the user.
• FTP – This is a protocol which is used to allow a user to transfer a file to another user. FTP uses separate data connections for the client and the server which is why FTP software is usually downloaded as either “Server” or “Client”. FTP is usually used to transfer files from a developer’s computer to a web server to display on a website.
• DNS – This protocol is responsible for giving each device on a network a name. This makes it easier to see what each device on the network is and can be used when devices connect to each other.

TCP/IP and the application layer are strongly linked as the protocols used in the application layer is what the rest of the layers protocols are based on. The protocols within the applications layer allow the application to determine whether data transfer has been successful or not. If it hasn’t the software application will pick this up because of the error checking specified in the protocol, it can then request this piece of data again.