Goodput vs Throughput: The Differences and How They Affect Your Network
Two key metrics that often come up in discussions about network performance are throughput and goodput. While these terms may seem similar, they highlight different aspects of your network’s efficiency and misunderstanding them can lead to poor decision-making that can impact the way you manage your network and your business’ resources.
Throughput measures the total amount of data flowing through your network, including overhead like headers and retransmissions. Goodput, however, focuses on the amount of useful data successfully delivered to its destination, excluding any unnecessary overhead. This distinction is essential for assessing the true performance of your network, particularly when it comes to end-user experiences such as video conferencing, file transfers, or cloud-based applications.
if you're an IT pro or network admin, we’ll clarify the differences between throughput and goodput, explain how they directly impact your business operations, and offer strategies to accurately measure and improve both metrics. Understanding and optimizing these metrics will help you make informed decisions that improve network performance, enhance user satisfaction, and ultimately support your business’s goals.
What is Throughput?
Throughput refers to the total amount of data that successfully passes through your network over a specific period, typically measured in megabits per second (Mbps) or gigabits per second (Gbps). This metric gives a snapshot of how much data is being transferred across your network, providing an indication of your network’s capacity to handle traffic.
How Is Throughput Measured?
Throughput is relatively straightforward to measure because it includes all the data sent across your network, including both the useful data and any additional overhead such as headers and retransmissions.
Here’s how throughput is typically measured:
Network Performance Monitoring Tools: One of the most common and accurate ways to measure network throughput is by using a network monitoring tool, whether synthetic or packet capture-based. These tools allow you to track key performance metrics in real time, ensuring that you have an accurate view of your network’s health and performance.
Speed Tests: Online tools like Speedtest.net or Fast.com provide an easy way to measure raw throughput between your device and a test server. While this is convenient, it only reflects your throughput in a real-world setting and may not be fully representative of your network's internal performance.
Throughput Formula:
What Are the Limitations of Throughput?
While throughput provides a valuable high-level overview of data transfer rates, it has limitations. Since throughput includes all the data, such as protocol overhead (headers, control messages) and retransmissions, it doesn’t always give an accurate representation of network performance, especially when issues like packet loss or congestion occur.
What is Goodput?
Goodput refers to the amount of useful data that is successfully delivered to the application layer, excluding any overhead such as headers, retransmissions, and control messages. In simple terms, it’s the actual data that gets to its destination and can be used by the application, offering a better measure of network efficiency from an end-user perspective.
A Metaphor Explaining Goodput vs. Throughput
Imagine a truck delivering goods. The total weight the truck carries is like throughput—it includes not just the actual product, but also packaging, padding, and any other materials.
Goodput, on the other hand, is like the actual product delivered to the customer—just the usable, valuable part, excluding the extra packaging. So while throughput tells you how much was transported, goodput tells you how much of it is actually useful.
Why Is Goodput Important In Your Network?
Goodput is a more accurate reflection of user experience. In scenarios like video streaming, file transfers, or VoIP calls, goodput directly impacts how smoothly these applications perform. For example, a high throughput might show that a large amount of data is being transferred, but if the goodput is low due to retransmissions or overhead, the user’s experience may still suffer.
How Is Goodput Measured?
Goodput is more complex to measure than throughput because it only focuses on the useful data that reaches its destination without retransmission or unnecessary overhead. Here are a few common methods for measuring goodput:
Packet Analysis Tools: Tools like Wireshark allow you to capture and analyze network packets, helping you identify the payload size (the useful data) versus the total transmitted data, which includes headers and retransmissions.
Application-Layer Monitoring: Monitoring tools that track TCP ACKs, retransmissions, and application-level transfer logs are ideal for measuring goodput. These tools help you understand how much useful data is being delivered to the application layer, excluding any unnecessary overhead.
Goodput Formula:
Goodput vs Throughput: What Are the Key Differences?
While both throughput and goodput are essential metrics for understanding network performance, they serve different purposes. Throughput measures the total amount of data transferred, while goodput focuses on the actual useful data delivered to the application layer. Understanding these key differences helps you get a clearer picture of your network's performance and user experience.
The Differences Between Throughput vs Goodput & Why They Matter
Both throughput and goodput provide valuable insights into network performance, but focusing on the right metric at the right time can make all the difference when it comes to diagnosing and optimizing network issues.
Performance Misconceptions: Understand network performance from the end-user perspective
A common misconception is that high throughput equals high performance. While throughput can provide insights into network capacity, it doesn't necessarily mean the network is performing well from a user experience standpoint.
Use Case Examples
Goodput vs. Throughput For VoIP Calls
Imagine you're on a VoIP call. Your throughput might appear high, showing that a large amount of data is being transmitted between your device and the server. However, if jitter (delay variation) and retransmissions are affecting the call, the goodput could be low. This means the call quality suffers despite high throughput.
Goodput vs. Throughput For File Transfers:
During a file transfer, throughput might show high speeds, but this could be misleading. Often, the TCP overhead can skew the perception of performance, making the transfer appear faster than it is. In reality, the goodput is lower because the network is spending extra bandwidth on retransmitting lost packets and managing control messages. By analyzing goodput, you can identify whether issues like packet loss or network congestion are reducing the efficiency of the transfer.
How to Measure and Improve Goodput
To accurately monitor and improve network performance from a user experience and application standpoint, measuring goodput does play a major role. Below are some common tools for measuring goodput and strategies to improve it.
Tools to Measure Goodput
- Packet Analyzers (e.g., Wireshark): Tools like Wireshark allow you to capture network traffic and analyze the packets being transmitted.
- Application-Level Logs: Checking application logs can provide insights into the actual data transfer.
- Obkio Network Monitoring: Obkio’s Network Monitoring Tool offers deep monitoring of network performance, including goodput.
How to Improve Goodput In Your Network: 3 Tips
1. Reduce Retransmissions (Optimize TCP Windows): Retransmissions can significantly impact goodput. To reduce retransmissions, optimize your TCP window size.
2. Lower Protocol Overhead (Use Newer Transport Protocols): Protocol overhead can take up a significant portion of your network’s bandwidth. One way to lower overhead is by using newer transport protocols like QUIC.
3. Avoid Congestion and Packet Loss: Network congestion and packet loss are major culprits in reducing goodput. To avoid these issues, ensure that your network is properly provisioned to handle expected traffic loads.
What is the Impact of Goodput & Throughput on Network Performance?
Both throughput and goodput provide valuable insights into network performance, but they affect your network's performance and user experience in different ways.