File transfer protocol (FTP)

Several protocol are used for transferring files from one system to another over a computer network. Of these FTP is among the earliest and most efficient one. It can be used to upload and download files, change directories etc.

FTP is a client server protocol used to access files store in different FTP servers connected to the internet. A user needs FTP client software on his local computer to communicate with the server. FTP works along with TCP for maintaining reliability in data transfer. Most web browsers now a days include an FTP client. Hence one can use a web browser for the purpose also.

Operation : To interact with an FTP server, the client first logs into the server by specifying the domain name of the FTP server. Using appropriate commands the user can then browse through the directory listing and finally select and download/upload the specific files. After the transfer is completed, the program is quit.

During communication, FTP opens two simultaneous connections. The first one is the control connection and is used to send the commands. During a file transfer, the files data is then transferred across different data connections.

Modes of File Transfer : There are two different modes of file transfer. For downloading text files by default FTP uses ASCII mode to transfer files. For downloading graphics, audio, video executable or any other non-text file one has to select binary mode.

Security and Login : When FTP first contacts a computer, the remote server asks the user to enter a login name and password before allowing access. This procedure helps to keep the data secure. However to allow general public to access files one has to type the login name as anonymous and password as guest or the email address of the client.

Advantages of using FTP

1. Supports File Queuing : Using FTP, files can be queued up for upload and download purpose.

2. Resume download : If a file download gets interrupted midway due to some reason, then FTP will download the remaining of the file only, when the connection is resumed.

3. Automate File Transfer : One can make a program use FTP to automatically transfer files at specific times during a day. This can help to take daily backups of files.

4. Easy Upload : Uploading files using FTP is much easier than using HTTP.

Disadvantages of using FTP

1. Interface : File transfer using FTP is not that user-friendly as HTTP.

2. Command Based : For better handling of FTP, one has to learn and remember various commands, as it has basically a command line based interface.

Hypertext Text Transfer Protocol (HTTP)

HTTP is first appeared in 1990, is another client server based file transfer protocol. It has almost replaced FTPs command based interface for file transfer, with a more user-friendly point-and-click graphical interface, that supports hypermedia. Web browser software acts as a client to download files from the web server. HTTP works along with TCP for maintaining reliability in communication.

Operation : To access any website using HTTP, the URL of the site is first written in the browser search box. The browser then connects to the DNS server to get the IP address of the web server where the website is hosted. The web browser, using HTTP, then makes a direct connection with the web server. The web server in turn transfers the required file to the web browser using HTTP. It allows the client and server to maintain the connection until all objects on a page are transferred. After the transfer is completed, HTTP terminates the connection.

Security : HTTP connections can be secured using the secure HTTP or HTTPS protocol.

Advantages of using HTTP

1. Widely used : Most sites that offer content for downloads have their files hosted in an HTTP server so that visitors can easily browse and select their files.

2. Faster Transfer Rate : It is faster to transfer multiple files using HTTP than using FTP.

3. Single connection multiple transfer : For HTTP, a client can maintain a single connection to a server and keep using that for any number of transfers.

Disadvantages of using HTTP

Less secure : HTTP does not use any encryption and request and responses are visible to anyone between the communication servers. HTTPS is a better protocol in that respect.

Extra overhead : File transfers with HTTP include a set of headers that contain additional information about a file and can be a significant part of the total data transfer for small files.

Difference between FTP and HTTP