Difference between TCP and UDP protocols

Ruth C. | June 17, 2020

TCP and UDP protocols have a pivotal role in data transmission online. UDP is the ideal choice for time-sensitive communications, while the TCP focuses on preventing errors, loss, and duplication. Hence, developers need to evaluate the scenarios in which these protocols operate. For instance, live support chats usually apply UDP, while TCP is an essential component of email services. Since you use these protocols daily, it is about time to meet them.

IP protocols and typical data exchanges online

All internet-connected devices feature a unique IP address that allows them to send bits of data to each other. The protocols neatly divide data into the so-called datagrams or packets to simplify the transmission.

These packets resemble the typical letters you send through the postal office. They have two addresses: the sender and the recipient. So, the IP protocol guarantees that your requests reach the final location successfully. TCP and UDP protocols step in when the divided data needs to be reassembled again. So, they are responsible for effective data transmission, but their error-checking processes differ.

How TCP and UDP transfer data

While the TCP and UDP protocols strive for the same outcome, their implementation is different. TCP is the preferred protocol as it takes additional measures and follows the sequence numbers in the packets’ headers. Hence, this manner of reuniting packets into their original form reassures that recipients get the data in the correct order. Furthermore, it uses an additional test known as the checksum. It scans the packets for errors or corrupted data. So, in simpler terms, the TCP protocol warrants that the recipient receives the whole message.

On the other hand, UDP takes a less demanding approach. It recollects and combines datagrams instead of packets, but these terms refer to the same divided chunks of data. This protocol does not verify that the recipient receives the full collection of datagrams. So, if some data is lost, it won’t resend it. Furthermore, UDP does not follow sequence numbers. Hence, the data can violate its original order. One thing that these protocols share is the checksum feature, analyzing data for traces of corruption or unsolicited changes.

Since TCP executes additional actions, it is slower. While a couple more milliseconds might not be disruptive enough for you to notice, some performance-critical activities require extra attention to speed.

Use cases of these protocols

Reassuring the integrity of transmitted data might not always be the top priority. Sometimes, people and services value speed as it is the critical element in their success. Let’s review the situations when both of these protocols work best.

  • TCP for reliable and secure data exchange. Whenever the security and confidentiality of data exchanges are the main priority, this protocol is the best. It has critical procedures for ensuring reliability in situations when the timing is not as crucial. Hence, this protocol is prevalent in the technology behind HTTP, HTTPS, email services, and other applications that require some thorough examination of packets.
  • UDP for activities that require high-speed and instant communication. The UDP is a widespread protocol in video content streaming, live chats, gaming, and other time-sensitive applications. Since it does not perform the lengthy error-checking, it functions faster. While the elapsed time differences are minor, they can play a huge role in the response time. So, developers that need to reassure extremely high-speed data transfers opt for this performance-oriented protocol.

Which protocol is the best for a VPN?

The industry-standard option is to use the UDP protocol for VPN applications. Atlas VPN follows this tendency and applies it as the default protocol. By applying UDP, we can reassure high-speed performance when users stream content or play games. Furthermore, this will offer lower latency and excellent responsiveness for all your online activities.

Alex T.

Ruth C.

Cybersecurity Researcher and Publisher at Atlas VPN. Interested in cybercrime, online security, and privacy-related topics.