In the world of digital communications, latency refers to the time delay between the initiation of an event and its detection or perception by an observer. Put simply, latency is the time it takes for data to travel from its source to its destination. This delay can be critical in many networked applications, impacting everything from web browsing speeds to real-time video calls and gaming.
Latency is often used interchangeably with the term “lag”, particularly in contexts where a noticeable delay affects the user experience. For example, when streaming a live video, if there is a significant lag, the visual and audio content appears out of sync or delayed, which can be disruptive.
In network communications, latency is commonly measured in milliseconds (ms), reflecting the tiny fractions of a second data packets require to traverse network paths. Lower latency results in faster, more responsive communication, while high latency can cause frustrating delays.
Understanding latency is essential for assessing network performance and ensuring that digital communications meet users’ expectations.
What causes network latency?
Several factors contribute to latency in communications. These causes can generally be grouped into physical, technical, and infrastructural elements that collectively influence the total time delay.
Routing and distance
One of the primary drivers of internet latency is routing—the path data packets take to travel across the internet. Data typically hops from one network node to another (routers, switches, servers) en route to its destination. Each additional hop adds processing time, thus increasing latency.
Distance plays a foundational role. The longer the physical distance data must travel, the higher the latency. For instance, signals traveling via fiber optic cables to distant servers require more time as they cover more ground.
An extreme example is satellite-based routing, where data must travel thousands of miles to satellites in orbit and back to Earth. This route inherently causes higher latency—approximately 241.2 milliseconds for a one-way trip—due to the sheer physical distance involved.
Routing inefficiencies, such as suboptimal paths or network congestion, can further amplify latency.
IP communications
Internet Protocol (IP) communications, which underpin most data transmission on the web, can introduce additional latency through phenomena like jitter and packet loss.
- Jitter refers to variations in packet arrival times. Inconsistent timing can cause packets to queue or require retransmission, increasing perceived latency.
- Packet Loss occurs when one or more packets fail to reach their destination, prompting retransmission and further delays.
Both jitter and packet loss are common in IP networks and can degrade real-time communications such as voice over IP (VoIP) calls, video conferencing, or online gaming by increasing latency and reducing quality.
Together, these factors underline why latency is not only about raw transmission speed but also about network stability and reliability.
Measuring latency
Accurately measuring latency is vital for network assessment and troubleshooting. Several methods and standards exist to evaluate latency:
- The Internet Engineering Task Force (IETF) has defined benchmark procedures in documents such as RFC 2544 and RFC 1242 to measure network performance indicators, including latency.
- One of the most common practical tools used to measure latency is the Ping command. Ping sends ICMP ECHO packets to a remote host and measures the time it takes for a response to return. The round-trip time (RTT) obtained provides an estimate of the network latency between the source and destination.
Ping results give network administrators valuable insights into connectivity, packet loss, and delay patterns.
Other advanced measurements involve Traceroute, which shows the path packets take and how much time each hop adds to the overall latency.
Together, these tools enable understanding the source and scale of latency issues to optimize network performance.
How to reduce latency
Reducing latency is crucial to enhancing the responsiveness and quality of online experiences. Various techniques and technologies are employed to minimize latency in digital communications.
Content Delivery Networks (CDNs)
A widely implemented solution is the use of Content Delivery Networks (CDNs). CDNs are networks of distributed servers strategically positioned closer to end users to cache and deliver static content efficiently. By serving files like images, videos, and scripts from nearby servers, CDNs significantly reduce the distance data must travel and thus lower latency.
When you visit a website integrated with a CDN, elements of the webpage load faster because they come from a local or regional server rather than a distant origin server.
This proximity not only decreases load times but also alleviates bandwidth bottlenecks and reduces packet loss risks, creating a smoother experience.
Bandwidth has Points of Presence (POPs) dispersed across the globe, allowing customers to connect to the nearest POP and minimise latency issues caused by geographical distance.
Internet Exchange Points (IXPs)
Internet Exchange Points (IXPs) are physical infrastructure through which different internet service providers (ISPs) interconnect their networks. By facilitating direct interconnections, IXPs optimize routing paths and reduce the number of network hops data must make.
This optimization minimizes delays caused by inefficient routing and decreases latency, especially for traffic exchanged between major networks or geographically close regions.
IXPs thus play an important role in enhancing internet performance by reducing the physical and logical distance that internet traffic must traverse.
How Bandwidth can help improve latency issues
Understanding latency is essential in designing and maintaining high-performance digital communication systems. From the causes rooted in physical distance and routing inefficiencies to the technical challenges of jitter and packet loss, latency affects how quickly and reliably data moves across networks.
At Bandwidth, we understand the profound impact of latency. Our platform is built on one of the largest and most advanced communication networks in the U.S., designed to deliver low-latency voice, messaging, and 911 services. We leverage intelligent routing and direct carrier connections to ensure rapid and reliable communication. Our solutions empower you to build communication experiences that are fast, responsive, and reliable.
Most importantly, we bring carrier-grade insights into network performance, enabling you to stay on top of it. Ultimately, understanding and actively managing latency is essential for delivering exceptional digital communication experiences.
