TCP vs UDP – What’s The Difference & Which Is The Best For Your VPN

So, you've taken the crucial step of getting a virtual private network (VPN). Now, you are confronted with the question: TCP or UDP connection?

This can be a confounding decision for those who don't know much about how Internet data traffic works. If you're in this dilemma, this article was created just for you.

Before we delve into comparing TCP vs UDP and how they are different, we need to go over the basics of how data is transferred over the Internet.

When a file is being transferred online, the bulk data is separated into small fractions (known as ‘packets'). UDP and TCP are standards that define the protocol of how these packets are moved from the sender to receiver.

First up, let's take a look at just what is TCP and UDP?

Transmission Control Protocol (TCP)

TCP is more widely used than UDP. However, that is quickly changing today. TCP is regarded as more reliable. When you send a file using TCP, the file is divided into small data packets and transferred to the receiver's computer where the data is reassembled. TCP creates a secure connection between the sender and receiver before the files are transferred.

TCP is unique because it is designed to ensure all the data packets are transferred successfully. An acknowledgment is sent to the source when each packet is received.

The packets are sent one after the other, and an acknowledgment is needed before the next packet is sent. If one file packet goes missing or gets corrupt during the transfer, it is resent until it is successfully received and the acknowledgment is sent.

This error correction feature of TCP makes it perfect for transferring sensitive files and when you have an unstable connection.

Advantages of TCP VPN

  • Effective: You can trust TCP VPN to transfer your files successfully especially when your Internet connection is not the most stable. It does not only guarantee the delivery of your files, but they'll be arranged in the same order that they were sent without any errors or missing parts.
  • Ubiquitous: TCP is widely used and is compatible with most standard ports.

Disadvantages of TCP VPN

  • Slower Transfer: Due to the error correction feature of TCP, transfers tend to be slow compared to UDP. Also, TCP features advanced encryption that contributes to its slow speed.

User Datagram Protocol (UDP)

UDP is the opposite of TCP. With a UDP connection, each data packet is sent only once. There is no handshake dialog between the sender and receiver to confirm that the data packet has been received before the next packet is sent. Therefore, even if some packets are corrupted during the transfer, it does not affect the process.

What UDP connection lacks in reliability, it makes up for in speed. This makes it particularly suitable for situations when the flow of data is essential like streaming and VoIP calls.

During a VoIP call, loss of some data packets will appear like a few seconds of silence. Meanwhile, if you are using a TCP connection, the system would seek to remedy the lost data packets by resending it, and this will ruin the flow of your call.

Although the potential loss of data packets when using UDP is usually highlighted, in reality, it doesn't frequently happen unless your Internet connection is not stable.

Advantages of UDP VPN

  • Faster: Since there is no need to verify and acknowledge receiving each data packet, UDP connection is faster than TCP. Also, it is not necessary to establish a secure connection between the sender and receiver before data can be transferred.

Disadvantages of UDP VPN

  • Unreliable: If you are downloading important files that you want to save on your computer, UDP connection is not the best option because it does not guarantee that your files will be received intact or that the data packets will be assembled correctly.

Ultimately, deciding whether to select TCP or UDP connection for your VPN depends on your personal preference. TCP is recommended for transferring large files that you want to save on your computer.

On the other hand, UDP is best for streaming, online gaming, and VoIP calls. Some people use UDP by default and switch to TCP to download files when they start to experience Internet issues.

Most VPN platforms allow you to choose which type of connection you want to use and despite the difference between TCP and UDP, It should be noted that both TCP and UDP VPN connections are highly secure. You do not have to worry about your privacy when using either of them.