Transferring data in the most efficient way and without error is a challenge. With security and storage playing hand-in-hand with cyber anomalies and attacks, the value of data has gone up while the barriers to data transfers have gone down. Luckily, there exists the FTP (file transfer protocol) which addresses this issue in a long-held method of data transfer between servers and clients. This method of file transfer relies on two-channel communication sessions to send data quickly and efficiently. The client logs into the server, connects to the directory, and establishes a port to send the data to the client. The server then establishes a connection through its own server address, which ultimately gives the client access to their website files.
FTP was actually established much earlier than the world wide web. Before the GUI interfaces of the software suites of today, FTP offered the ability to transfer files between server and client across the a network during the early stages of web development. Developed in 1971 by Abhay Bhushan, the benefits of an FTP client include the option of being able to select ports you can send data through. These ports act as gateways for all internet data transfer actions, and were created to help divide their duties (for example, the port 110 is used for email, while port 21 is used for FTP). This means that packets of data don’t get clogged in one area, causing connection issues and timeouts.
FTP was created out of the necessity of carrying out data transmission without having to learn a complex command line interface. With programs such as Filezilla, all you have to do is log in, then drag and drop your files to their desired location. With this in mind, it’s important to understand the differences between the two main connections made in FTP:
Control Connection: The control connection is used to establish a connection between the client and the server. This is called an FTP session, and is when the client requests a push or pull of data between the client and the server through commands. This can be thought of as the channel that transmits commands and actions between the client and the server.
Data Connection: The data connection is the actual transmitting of data between client and server. The session will timeout after the data is transmitted. This can be thought of as the channel that actually transfers and executes the files.
There are also two different modes that FTP can establish port connections:
Active: Active mode is when the client’s PC connects to port 21 on the server. This connection is considered active because the server initiates the connection.
Passive: In this mode, the client initiates the connection and manually enacts all connections.
The disadvantages of active mode is the fact that firewalls can prevent some ports from being accessed, and dictates what data can travel between client and server. For example, when the client tries to connect to port 21 on the server, the firewall may not allow traffic from the client’s port. The advantages of active mode would mean that the server is only receiving data and sending data from port 21 and 20, so firewalls can protect the integrity of the data that is passed between client and server. Keep in mind that the vulnerability of unencrypted password protection is a problem with port 21, so oftentimes the use of port 20 with FTPS (file transfer protocol secure) is used as an alternative method by implementing the SSL layer to encrypt your connection.
The disadvantages of passive mode is that the server is opening ports depending on the client’s needs which are not guaranteed to be protected by firewall. This makes it easier for the client, but opens the server to vulnerabilities.
Overall, FTP is a way of getting content out there onto the web. This relatively simple process is in part due to the early development of the web services that we all know today. Using this interface to access and share content has never been easier. Securing data can take seconds out of your day when considering how much you have invested in your business. Using FTP is not only fast, it is secure and it utilizes protocols that ensure your data is accessed by the right people with secure sessions.