What is the difference between TCP and UDP Protocols?

9 min read
January 8, 2024

In digital communication, networking protocols, such as TCP and UDP protocols, play a crucial role in ensuring seamless data exchange. Choosing the right protocol is essential to influence performance, data integrity, and user experience (UX).

Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are two key components in the Transport Layer. TCP ensures reliable, ordered data transmission, which is crucial for applications prioritising data integrity. Meanwhile, UDP prioritises speed and efficiency, accepting occasional packet loss.

This article explores the difference between TCP and UDP protocols when to use UDP vs TCP, and their mechanisms, strengths, and key features.

Table of Contents

  1. What is TCP protocol?
  2. Use cases of TCP protocol
  3. What is the UDP protocol?
  4. Use cases of the UDP protocol
  5. What is TCP vs UDP: comparison between TCP and UDP protocols 
  6. Performance considerations
  7. Security considerations 
  8. How to choose between TCP and UDP?
  9. Experience secure and frictionless meetings with Digital Samba video conferencing API 

What is TCP protocol?

The Transmission Control Protocol (TCP) is a communication protocol that provides a reliable and ordered pathway for data transmission. As part of the Transport Layer, TCP ensures secure and accurate information delivery across networks. 

Its working mechanism involves connecting two devices, a sender and a receiver before data exchange commences. This connection is a virtual circuit, ensuring a reliable and orderly data flow. 

Here is a list of key features of the TCP protocol. 

Use cases of TCP protocol

TCP's connection-oriented approach and robust features make it the protocol of choice for several use cases. Some of them include:

What is the UDP protocol?

The User Datagram Protocol (UDP) is a communication protocol that operates in the Transport Layer of the Internet Protocol (IP) suite. Unlike TCP, UDP takes a connectionless approach to data transmission. 

UDP facilitates the exchange of information between devices without establishing a dedicated connection beforehand, making it a lightweight and fast alternative.

Here is a list of features of the UDP protocol.

Use cases of the UDP protocol

The UDP protocol's unique characteristics make it the protocol of choice for several applications requiring speed and real-time responsiveness.

What is TCP vs UDP: comparison between TCP and UDP protocols 

To facilitate a comprehensive understanding of TCP and UDP, let’s explore a comparison between these protocols.

Features

TCP

UDP

Connection Type

Connection-oriented 

Connectionless

Delivery 

Guarantees correct delivery order

Doesn’t guarantee the correct delivery order

Reliability 

Reliable data transfer

Lower reliability

Overhead

Higher overhead due to setup

Lower overhead

Congestion Control 

Yes 

No 

Data Sequence

Maintains data sequencing

No sequencing

Data Retransmission

Yes 

No

Bandwidth Usage

Variable, adapts to congestion (Higher than UDP)

Generally lower

Error Checking

Yes

No 

Broadcasting

Not supported

Supports broadcasting

Speed

Slower due to connection setup

Faster due to simplicity

Security 

More secure due to reliability and error checking

Less secure, susceptible to attacks

Use Cases

File transfer, email, web browsing

Online gaming, video streaming, DNS lookups

Protocols

FTP, SMTP, HTTP, HTTPs, and Telnet 

DNS, VoIP, TFTP, DHCP, RIP, and SNMP

Performance considerations

When assessing the performance of TCP and UDP protocols, some key aspects influence the efficiency and responsiveness of data transmission. 

However, the choice between TCP/UDP protocols should align with the specific performance requirements of the application.

1. Bandwidth utilisation

TCP, with its reliability mechanisms and ordered delivery, tends to have higher bandwidth utilisation than UDP. While TCP ensures data integrity, it comes at the cost of additional protocol overhead, impacting the overall bandwidth efficiency.

On the other hand, UDP, with its lightweight approach, minimises overhead, leading to more efficient bandwidth utilisation but at the cost of lost or out-of-order data.

2. Latency and response time

In scenarios where low latency and swift response times are critical, UDP outperforms TCP. The connectionless nature of UDP allows for faster data exchange without the need for connection setup and acknowledgement.

This makes UDP the preferred choice for real-time applications like gaming and VoIP, where instantaneous responses are crucial.

3. Scalability

TCP excels in scalability for applications that demand reliable, ordered data transmission. Its connection-oriented approach ensures that as the number of devices increases, the protocol can manage and coordinate data exchange effectively.

However, UDP's connectionless nature makes it more scalable in scenarios where a vast number of connections need to be handled simultaneously, prioritising speed over reliability.

4. Impact on network resources

TCP's commitment to reliability and ordered delivery often leads to higher resource utilisation, as it maintains connection state information and manages congestion control.

In contrast, UDP's lightweight design minimises its impact on network resources, making it a favourable choice for applications requiring rapid data transmission. 

Security considerations 

Network security involves securing the core networking infrastructure from unauthorised access, theft, or misuse.

In network security, TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) exhibit distinct features and vulnerabilities.

Let's explore them below:

Security features and vulnerabilities in the UDP protocol

​UDP lacks built-in security features, making it inherently more vulnerable. While Datagram Transport Layer Security (DTLS) can secure UDP communications, the protocol remains vulnerable to Distributed Denial of Service (DDoS) attacks and spoofing. 

The absence of connection-oriented features, such as a three-way handshake, makes UDP susceptible to unauthorised access and data manipulation.

Security features and vulnerabilities in TCP protocol 

​TCP, with its connection-oriented nature, incorporates robust security features. The three-way handshake, the foundation of TCP communication, ensures a secure connection. 

Encryption and secure protocols, like Secure Sockets Layer (SSL) or Transport Layer Security (TLS), enhance security by introducing an additional layer of protection. These elements are integrated with TCP to offer increased security through authentication and encryption.

However, TCP/IP stack vulnerabilities pose challenges, as attackers may exploit weaknesses in the protocol stack to compromise security.

How to choose between TCP and UDP?

Selecting between TCP or UDP is a critical decision influenced by various factors, including application requirements and network conditions. When to use UDP vs TCP depends on specific considerations to ensure optimal performance and functionality. 

Let's explore the factors influencing the choice of TCP vs UDP.

Application requirements

  • Reliability: TCP is connection-oriented and guarantees reliable data delivery. Therefore, TCP is preferred if your application demands error-free and ordered data transmission.
  • Real-time communication: UDP is often favoured for real-time communication due to its low latency. Applications like online gaming or voice-over-IP (VoIP) benefit from UDP's speed, even though it sacrifices some reliability. 
  • TCP vs UDP speed: UDP is faster than TCP but does not perform error checking.

Network conditions

  • Packet loss tolerance: UDP is more tolerant of packet loss as it does not retransmit lost packets. In situations where occasional data loss is tolerable, UDP may be suitable.
  • Congestion: TCP adjusts its transmission rate based on network congestion, which can lead to delays. UDP, being connectionless, can perform better in situations with high network congestion.

Security

TCP provides a more secure communication channel with reliable and ordered delivery, making it preferable for secure data transfer.

Latency

UDP's lower overhead contributes to reduced latency, making it preferable for applications requiring real-time responsiveness, such as live broadcasting, video streaming, etc.

Choosing the right protocol for video conferencing

Now that we have discussed the factors influencing the choice between UDP and TCP, let’s discuss how to choose the right protocol.

Below are evaluation criteria to help you choose the right protocol for video conferencing

  • Evaluate application characteristics: Consider the sensitivity of the transmitted data. If maintaining the order and completeness of data is crucial, TCP is a suitable choice.
  • Assess network conditions: Evaluate the network’s stability and the bandwidth’s availability. TCP is more adaptive to varying network conditions, making it safer in less stable environments.
  • Consider communication patterns: Assess how the application communicates. If it involves constant data updates and real-time interaction, UDP may enhance the user experience.

A hybrid approach

Sometimes, a hybrid approach combining TCP and UDP is beneficial. This allows leveraging TCP’s reliability for critical data exchange and UDP’s speed for fast transfer to enhance the efficiency based on specific requirements within the application.

For instance, most web traffic relies on the HyperText Transfer Protocol (HTTP) with TCP as its transport protocol. However, TCP proves inefficient for brief web conversations, which constitute a significant portion of web traffic. The setup and teardown overhead of the TCP state is less than ideal for these short connections.

A hybrid approach, which employs TCP or UDP as the underlying transport protocol for web traffic, can address this challenge. UDP is used for short transfers like HTTP redirection to minimise TCP overhead while retaining TCP for reliable delivery and congestion control benefits.

Experience secure and frictionless meetings with Digital Samba video conferencing API 

For a comprehensive video conferencing solution that optimally handles diverse network conditions, consider embedding video room API. Our API employs TCP and UDP protocols, ensuring a seamless and reliable communication experience. 

Whether you prioritise reliability or real-time responsiveness, Digital Samba's hybrid approach caters to varied application needs.

For a video conferencing solution that leverages the strengths of both TCP and UDP, request a demo today to explore Digital Samba's video conferencing API!

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