What is the Difference Between UDP and TCP

If you use VPN’s, you see terms TCP and UDP. This quick guide shows the difference between UDP and TCP, and how they can affect your experience.
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Most VPN users see the terms TCP and UDP, and a good many may know they are to do with the protocols in some way, especially when you see OpenVPN over TCP or UDP.

Here we will look at what they are, how they differ, and what they are used for about your VPN.

We will also see the instances when each of them can be used.

Difference Between UDP and TCP

What is the same between TCP and UDP?

Both TCP and UDP are what you call network protocols. Both of these are used to send data packets over the internet.

It doesn’t matter how you communicate, be it opening a web page, online gaming, or sending an email, the data is sent in small packets of a specific size.

The way they work is to forward the TCP and UDP packets from your device to a web server or router until they find their destination.

You also find them in use to send packets of data to a certain IP address, which is connected to the internet.

Both of these protocols work on top of IP layer (Internet Protocol). It is this reason you hear TCP/IP or UDP/IP, it is these that are abbreviated in most cases to their respective letters.

These are the most commonly used protocol types, yet they are not the only ones that can be used to transfer packets. ICMP is another, but the focus is on TCP and UDP.

What is TCP?

TCP (transmission control protocol) is used more than UDP. As soon as you open web pages inside your web browser, your device will send TCP packets to the relevant server address. This is the request to the server to send information for the webpage.

This server replies when it sends TCP packets, which will be stitched together by the browser, and thus, you get the page on your screen.

If you click links in the page or navigate to another page, the browser sends more packets, and the server will respond by returning more data packets containing the new information.

TCP connections are not one way, because this stream is continually moving backward and forward between servers and your device.

TCP will give each packet a number, so they are received in order. Once one packet is received, it sends a confirmation to the sender.

If one isn’t received, the sender assumes the packet wasn’t received, thus sends and another packet.

Reliability is the main focus with TCP, so there is a lot of error checking in the transmissions.

This is to be sure there is no lost data. Aside from this, these packets are also checked to make sure they are not corrupted in any way.

It is this checking that makes sure files are received in perfect condition regardless of there being any network issue.

What is UDP?

UDP packets are very similar to TCP but without the error checking or any error correction. This makes it lighter in use.

When packets are put in order, and there are resend requests like in TCP transmissions, this takes time and will slow connections a little.

UDP is much faster because it foregoes these overhead steps.

The sender will send packets to the recipient, and the sender isn’t concerned if the recipient received them or not.

It continues sending packets as they are requested until the communication ends. If any of these packets are missed, then there is no way they can be asked for again.

UDP is most used when reliability isn’t of great concern. Online games are one of the key areas where they are used along with video conferencing or broadcasting.


Quick Differences

Connection TypeConnection orientatedConnectionless
Flow ControlPackets sequencedNo sequencing
SpeedSlower – with overheadFaster – no overhead
Header SizesHave large headerMinimal headers
Error detectionChecking and correctionChecking but no error recovery
AcknowledgmentSent by the recipient of receiptNo acknowledgement sent
Transfer methodStreams with congestion controlSingle packets with no congestion control
Application typesBrowsing, email, file transferGaming, streaming and video calls

TVP vs. UDP VPN Ports

Data, which travels to your device, will be accepted through various TCP or UDP ports. Your IP identifies your computer or device.

However, there are numerous ports allocated to your device. In total, you can 65,535 UDP and 65,535 TCP ports.

The data is sent to your IP and to a specific port, which relates to the type of data packet it is.

When you begin to look at the use in VPN’s, users wonder which one they should use.

OpenVPN is the industry standard, and it performs well with both types of transport layer protocols.

Both of the protocols deliver high levels of security and privacy with your VPN, but knowing which is best for your usage can take some consideration.

If you need faster connections, then you will use UDP. However, if you need the reliability you get from the TCP flow control, then you would opt for this protocol.

Gaming or streaming can use UDP because a couple of dropped frames won’t make a difference, however, if downloading files, you will need to opt for TCP because a missed data packet will lead to a corrupt file.

The application would decide which one to best use, and the top VPN server networks make this change automatically without user intervention.

Users can change it manually if they want to delve into the settings, bit in some instances, leaving it set to one, and you may find some services become unreliable or don’t work as intended.

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