Latency: IT definition
Latency is an IT concept that defines the delay between sending a request and receiving the response. In network terms, latency is the time it takes for a data stream to travel from point A to point B. It is usually expressed in milliseconds (ms). Low latency is essential to ensure a smooth user experience, particularly in applications requiring a fast response, such as online gaming and videoconferencing.
What is network latency?
Network latency refers to the propagation delay of incoming data across a network. It is impacted by several factors, such as geographical distance, the number of network hops, and the performance of equipment such as routers and Ethernet cables. Understanding network latency is vital to optimizing the performance of IT systems and ensuring optimum service quality.
The difference between latency and bandwidth
It is important to differentiate between latency and bandwidth. While bandwidth measures the amount of data that can be transmitted over a network in a given time interval, latency looks at the delay in data transmission. High bandwidth does not compensate for high latency, as a fast connection can still encounter significant delays if high latency occurs.
What is low latency?
Low latency is the minimum delay between sending a request and receiving a response in a computer system or network. Low latency is essential for fast, seamless interactions, in applications where responsiveness is essential, such as online gaming, video conferencing and real-time financial transactions. Low latency delivers data almost instantaneously. It improves the user experience and ensures more efficient operation of digital services. Latency is measured in milliseconds (ms), and low values indicate fast, efficient data transmission.
Acceptable latency is a data transmission delay that is low enough to guarantee smooth and efficient application performance, generally less than 100 milliseconds, thus delivering an optimal user experience in most network environments. Each business (banking, content operators, etc.) needs to set a latency threshold that must not be exceeded. For example, for a trading company, latency should not be higher than 5 milliseconds.
What causes high network latency?
Geographical distance
The distance between two network points has a direct influence on latency, because the further data has to travel, the longer the propagation time.
Number of network hops
Each intermediate device, or hop, that data must pass through adds a small additional delay, thus increasing total latency.
Network congestion
Congestion occurs when demand surpasses network capacity, slowing down data processing and increasing latency.
Equipment performance
The performance of network equipment, such as routers and servers, plays a major role in latency. Obsolete or poorly configured equipment can lead to high latency and packet loss.
How to measure network latency?
The ping command
The ping command is a simple but effective tool for measuring latency. It sends data packets to a specific IP address and measures the time it takes to receive a response, thus providing a latency estimate.
Round-trip time (RTT)
Round-trip time (RTT) is a common measure of latency, calculating the total time taken for a packet to reach its final destination and return to its starting point.
Time to first byte (TTFB)
Time to First Byte (TTFB) is another measure of latency, evaluating the time taken for a server to respond to an initial request with the first byte of data.
Latency impact on applications
Online gaming
In online games, high latency can cause significant delays, negatively impacting user experience and gameplay.
Videoconferencing
Low latency is crucial for videoconferencing, to keep communications running smoothly and avoid any interruptions.
Streaming services
Streaming services benefit from low latency to offer continuous playback without buffering.
Financial applications
In finance applications, latency can influence the transaction speed and updating of data, which is critical for real-time trading.
What are the best solutions for reducing latency?
Optimizing network infrastructure
Enhancing network infrastructure performance by hardware upgrades and configuration optimization can reduce latency.
Using Content Delivery Networks (CDN)
CDNs deliver content closer to end-users, reducing the distance over which data is propagated, and thus reducing latency.
Network hops reduction
Minimizing the number of hops to reach a destination can significantly reduce latency.
Enhanced server performance
Optimizing servers to process requests faster helps reduce latency, thus improving the user experience.
Understanding and managing latency helps optimize network performance and ensure optimum quality of service. By applying effective strategies to reduce latency, companies can improve the responsiveness and reliability of their systems, addressing the increasing needs of the digital economy.