TCP vs UDP: Why UDP is Preferred Over TCP For Online Multiplayer Games

Those who are new to computer networking, or those who have dug through the network configurations of some applications, have invariably come across these terms: TCP and UDP. An Internet protocol suite consists of the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). A TCP and UDP connection are two methods of sending information over a network.

Multiplayer gaming is a different world where you need the optimal performance of servers; otherwise, end users don’t enjoy the desired experience. The debate of TCP vs UDP protocol isn’t new. These both have multiple positives and negatives, but don’t fret; we have covered them all.

But before going into a full-fledged discussion of TCP vs UDP for multiplayer gaming, let’s first understand the basics.

The Background

Despite knowing what they represent, it isn’t easy to know which protocol to use or why. Among the different features and functions that TCP and UDP offer, each has its advantages and disadvantages. Even though UDP is known for being faster as well as more modern, many systems continue to use TCP to download batches of data. To determine which protocol is most appropriate for the user, they should consider their specific IP needs.

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This guide will tend to highlight the differences between UDP and TCP. Additionally, you will discover which protocol is best suited for streaming, gaming, and web browsing, as well as which protocol is best suited for VPN connections.

Without further ado, let’s delve into it;

What is TCP?

With TCP/IP, you can determine how a particular computer should be connected to the internet and how data transfer will occur. In the case of multiple computer networks connected, it allows you to create a virtual network.

Transmission Control Protocol and Internet Protocol are also known as TCP/IP. Over an unreliable internet, it provides a highly reliable end-to-end byte stream.

What is UDP?

The UDP protocol is a datagram-oriented protocol. This type of network transmission is used for broadcasts and multicasts. A datagram is a unit of exchange with a packet-switched network. UDP functions similarly to TCP, but it eliminates all the error-checking processes and all the back-and-forth communication.

Now, let’s move to the major question, how do these two function;

TCP VS UDP: How do they work?

Three-way handshakes are used to establish TCP connections. Connections are initiated and acknowledged through this process. Data transfer begins once the connection has been established, and when the transmission is completed, the virtual circuit is closed to terminate the connection.

For order, reliability, and data integrity, UDP uses a simple transmission method without implied handshakes. To avoid the overhead associated with such processing at the network interface level, UDP assumes this error checking and correction is not necessary and is already performed in the application. Multicasting and packet broadcasting are also supported.

The difference between UDP and TCP

1. TCP vs UDP: Key Features

Here are the feature differences between TCP and UDP. 

Some of the critical features of TCP are as follows:

• Acknowledgments of delivery
• The retransmission
• Congestion in the network delays transmission
• Detect errors easily

UDP has the following important features:

• Provides bandwidth-intensive applications with packet loss tolerance
• Decreased delay
• Packets are sent in bulk
• Data loss is possible
• Small transactions are allowed (DNS lookups)

2. UDP vs TCP: Usage Difference

There are plenty of advantages to using UDP over TCP. Here are a few comparative usage differences between UDP and TCP. 

TCP can be used for the following purposes:

• Establishing a connection between different types of computers is made easier with this tool.
• Independently runs on any operating system
• Provides support for a wide range of routing protocols.
• Internetworking between organizations is enabled by it.
• Independent operation is possible.
• Provides support for several routing protocols.

The following are examples of how UDP can be used:

• In addition to time-sensitive applications, UDP is also widely used by servers that answer small queries for a large number of clients.
• Multicasting and packet broadcasting are both supported by UDP.
• Aspects of Voice over IP, Domain Name Systems, and online games also rely on it.

3. UDP Vs TCP: Which one is Faster?

This factor is extremely important for multiplayer games.

Unlike TCP, UDP does not establish a connection between devices before sending data, nor does it verify that all data was received. Data is simply sent out to any device that requests it, and it continues to send data until either the other device disconnects from the network or there is no more data to send.

Think of it as sipping water from a hose rather than from a bottle. There is no doubt that both methods will quench your thirst, but you will probably end up with a damp shirt if you choose to use the former method.

So, in terms of speed, UDP is faster than TCP. 

4. UDP VS TCP: Which one is more Secure?

The UDP nor TCP protocols were neither designed with security in mind. The packets can be plain text or encrypted, and they’re used to transport data over the internet. It is usually up to other protocols or applications higher up the communications stack to handle security.

TCP sequences and acknowledges packets, which makes injecting malicious data more difficult than with UDP.

The security concerns associated with either of these protocols are negligible when used in conjunction with a VPN in practice. For privacy and security concerns, both TCP and UDP support the features that are used to keep the user safe.

5. TCP vs UDP: Which one Reduces Latency?

In multiplayer games, latency is a major issue. If any game has a considerable amount of latency, it simply means UX is compromised.

TCP requires acknowledgment which requires more bandwidth, thus more latency. In contrast, UDP doesn’t have any such requirement. That’s why, for multiplayer gaming, UDP is a viable option.

6. TCP vs UDP: Which Consumes More Data?

Because TCP includes a larger amount of information in the header of each data packet, it consumes a higher volume of data than UDP. Due to this, TCP is more reliable than UDP, though less efficient.

Internet data packets have headers, which are like addresses on envelopes. The protocol contains all the information necessary to get data to the correct location, as well as any additional information that may be required.

Data packets transmitted via UDP and TCP show the source and destination ports, the size of the packet, and the checksum. Nevertheless, TCP also includes extra information to ensure that the message is delivered correctly.

(A checksum is calculated twice on the data: once before it is sent and once after it is received. If the checksum differs at the receiving end, the data has been corrupted.)

Additionally, TCP involves more communication between the sender and receiver. When a packet is received using TCP, the receiver ACKs (Acknowledges) every other packet. Any packets that are lost are resent. Therefore, TCP consumes more data than UDP.

TCP vs UDP: Which one is Better?

There is no doubt that UDP has an advantage over TCP due to faster speed. The question is, how much? It depends on what you’re using it for.

In this case, the question of speed is not the appropriate one to ask. The question should be one of suitability. The requirements of different applications differ, and in some cases, TCP may prove to be more efficient and faster than UDP.

In theory, TCP is slower than UDP, but in some practical applications, it can be fairly fast. As an example, streaming websites such as Netflix and YouTube use TCP despite the fact that UDP is faster. Why is this so?

The TCP protocol enables you to buffer data and load some of the videos beforehand so that the stream runs smoothly. This functionality is not available in UDP.

Streaming live video, playing online games, and communicating online are better achieved with UDP. The reason for this is that these applications require the fastest data transmission possible. There isn’t much difference between losing data on the way and not losing data, which is why you may see skips in live streams or video calls.

While UDP can handle most tasks, TCP can be necessary at times. In general, your connection alternates between the two automatically. However, you’ll need to use UDP when using a VPN. This is because most VPNs run exclusively on UDP and don’t allow you to change protocols.

TCP or UDP: What Should You Choose for Gaming?

The TCP protocol involves a lot of back and forth, which consumes a lot of bandwidth as well as adds latency. A smooth online gaming experience depends on the fast data transmission offered by UDP. Despite UDP’s speed, some data gets lost. If this is true, why does it make it a better choice for online gaming?

Since only the most recent data is needed to play online games, data loss is not a problem. The flow of information can continue at a faster pace with newer data packets replacing the previous data. In case of a fast enough transfer speed, lost data is unnoticeable. Protocols like TCP are stream-based as well. 

Data packets are separated into smaller pieces, then queued up until they are large enough to be sent as a package.

In most online multiplayer games, the data packets used for communication are small. Before sending small packets to the receiver, TCP waits for a queue of small packets to line up. Consequently, the gameplay is choppier than ever. UDP, on the other hand, sends every packet immediately. As a result, gaming and every other time-critical application should be run on it.

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When is TCP Preferred over UDP?

You’re better off using UDP for most of your online activities. Having said that, why is TCP so widely used on the Internet?

Reliability isn’t the most important feature of TCP. It’s commonly used for a variety of internet applications. This is because it uses data flow control, a feature that prevents networks from collapsing due to congestion.

Data packets can be sent to one receiver by too many senders when only a limited number of packets can be transmitted. As a result of congestion, the overall transfer process is slowed down, and the connection may collapse. The internet is slowed down because too many people use it simultaneously during peak hours.

TCP controls data flow to ensure smooth operation. The traffic is kept steady by only sending a limited number of packets per second. Most networking applications do not use UDP since it keeps sending every packet regardless of the network’s congestion.

TCP vs UDP: Criteria for usage in Massive Multiplayer Online Gaming

Massive multiplayer online (MMO) games often require developers to select between the usage of UDP versus TCP. TCP’s congestion control algorithm in this scenario treats packet loss as a sign of bandwidth limitations and automatically throttles packets sent as a result. The latency can be significant on Wi-Fi or 3G networks.

Christoffer Lernö, an experienced developer, recommends the following criteria for choosing TCP or UDP:

• When it’s okay to have occasional delays, use HTTP over TCP for occasional, client-initiated stateless queries.
• A persistent plain TCP socket can be used when both client and server can send packets independently, but an occasional delay is acceptable (e.g., Online Poker, various MMOs).
• If there will be occasional lag and both client and server will be able to send packets independently (as in multiplayer action games and some multiplayer strategy games), choose UDP.

Conclusion

Having explored the differences between TCP and UDP, it is evident that any multiplayer games developer can greatly benefit from UDP. Aside from avoiding transport traps and clogged networks, UDP offers outstanding streaming speeds. With UDP enabled for Lifesize, companies can enhance workflows, gain less overhead, and experience fewer interruptions, making this a win-win situation.

Attribution

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