TCP vs. UDP: Know the Differences
What is TCP?
TCP (Transmission Control Protocol) is a network protocol that transfers your data over the Internet from your device to a web server. You can use TCP when you chat with your friends on Skype, send emails, watch online videos, or simply surf the web.
TCP depends on the connection, so it establishes and maintains a connection between the recipient and the sender during the transfer of data. Ensures that the data arrives completely intact. Due to its reliability, TCP is the most popular network protocol.
What is UDP?
UDP (User Datagram Protocol) is another widely used network protocol. It is less reliable but faster and more straightforward. It is often used in situations where high speeds are critical, such as streaming or gaming.
UDP is not connected, so it does not establish a prior connection between two parties. Therefore, you may lose some data along the way, but in return you will get much faster speeds.
How does TCP and UDP work
TCP is more reliable than UDP. It transmits your data packets from your device to the web server. UDP is faster and simpler, but it does not guarantee the delivery of packets.
Here’s what you do to submit your data:
- TCP assigns each data packet a unique identifier and sequence number. This allows the receiver to determine which packet has been received and which packet will arrive next.
- Once the data packet is received, and if it is in the correct order, the recipient sends an acknowledgment to the sender.
- The sender can now send another packet.
- If the packet is lost or sent in the wrong order, the receiver remains silent, indicating that the data packet itself needs to be resent.
Because data is sent sequentially, it helps with data congestion and flow control, and makes it easier to spot and fix any errors. This also means that the data sent over TCP is more likely to reach its destination completely. However, it has a downside. There is a lot of back-and-forth communication between the two parties, so it takes longer to establish a connection and exchange data.
UDP completes the same task without the need for unique identifiers or serial numbers. It sends data in a stream and only has a checksum to ensure that the data arrives without corruption. UDP has almost no debugging, and it doesn’t care about lost packets. It is more error prone, but sends data much faster than TCP.
Is UDP secure? It is almost impossible to set up a firewall that only allows some UDP connections and blocks the rest. However, while it is much easier to secure TCP, UDP connections are not left completely unprotected. Users can use proxies for specific applications or create a tunnel connection between the remote user and the company’s internal network.
What is the main difference between TCP and UDP?
The main difference between these protocols is that TCP is a connection-oriented protocol, while UDP is a non-contact protocol. Each of the protocols has strengths and weaknesses. One is faster, the other is more secure. Here’s how they compare side by side:
|Transfer method||Packages are delivered in sequence||Packages are delivered in a stream|
|Detecting and correcting errors||Yes||number|
Both UDP and TCP divide your data into smaller units called data packets. These include the sender and receiver IP addresses, different configurations, the actual data you’re sending, and the trailer – the data that indicates the end of a packet.
So, which is better – UDP or TCP? As in all of these cases, it all depends on what you’re using it for. If you need fast and continuous data transfer for an application to work properly, you will have to use UDP. Other than that, TCP is a stable and reliable protocol for transferring data and not losing any of it along the way.
TCP vs. UDP: Speed Differences
UDP is faster than TCP but also more error prone. The reason is that UDP does not use such careful packet inspection as TCP and uses a more persistent data flow. TCP sends its data in sequence, so it uses more control over the flow. It makes the communication more secure and smooth but reduces the speed due to the many back and forth connections between the sender and receiver.
OpenVPN: TCP vs. UDP
Are UDP and TCP protocols compatible with VPN services? Yes. Both work with OpenVPN, which is the open source VPN protocol used by many of the leading VPN providers, including NordVPN. OpenVPN works on network protocols and both provide privacy and security. Choosing the option depends on the purpose for which you are using your VPN. TCP is more reliable, so you might think that TCP is the best option, but there are times when UDP may be preferred.
UDP is a great option if you are gaming, streaming or using VoIP services. You might lose a packet or two but it won’t have much of an impact on your overall connection. Using TCP for these services may cause delays (especially if you are connected to servers on the other side of the world), which could spoil your experience completely. Therefore, OpenVPN over TCP is recommended for stable uses such as sending email, browsing the web, and transferring files.
What protocol does NordVPN use?
NordVPN wants to offer the best browsing experience without compromising on speed, so we use the UDP protocol by default. We recommend trying UDP first and switching to TCP only if you encounter any problems.
To change UDP to TCP on NordVPN (for Windows users):
- go to Settings by clicking on the gear icon in the upper right corner;
- Choose advanced From the menu on the left side;
- under protocol Choose TCP.
To change UDP to TCP on NordVPN (for macOS users):
- open the Preferences Panel by clicking on the slider button in the upper left corner or finding NordVPN in your menu bar and choosing Preferences (Default hotkey: Cmd +,).
- Connectivity: Prefer UDP over TCP It will be turned on by default. Click the check box to turn it off.
If your speed drops, you can also try some tricks to increase your VPN speed.
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