What Is Latency?

In simple terms, latency is network delay. Lower latency generally means faster response times, which is especially important for interactive applications such as online gaming, financial services, APIs, real-time communications, and cloud-connected workloads.

Latency is different from bandwidth. A connection can have high bandwidth and still have high latency if data has to travel a long distance or follow an inefficient network path.

How Is Network Latency Measured?

Network latency is commonly measured in milliseconds. One of the most widely used measurements is Round-Trip Time (RTT), which measures how long it takes for a request to travel from the source to the destination and for a response to return.

For example, an RTT of 40 ms means that the measured round trip takes approximately 40 milliseconds.

RTT is not exactly the same thing as one-way latency. It is a practical measurement of the complete round trip and is commonly reported by tools such as ping. Network conditions and asymmetric routes can affect the relationship between one-way delay and RTT.

For production systems, average latency does not always tell the whole story. p95 and p99 latency show the delay experienced within the slowest 5% and 1% of measurements respectively, helping identify occasional spikes that an average can hide.

Key Takeaways

• Latency measures network delay between endpoints.
• It is usually expressed in milliseconds.
• RTT measures the time for a request and response to complete a round trip.
• Lower and more consistent latency generally improves responsiveness.
• Physical distance, routing, congestion, and network infrastructure can all affect latency.
• High bandwidth does not automatically mean low latency.

What Causes Network Latency?

Network latency is affected by multiple parts of the communication path rather than by a single factor.

Physical Distance

Greater physical distance generally increases latency because data has to travel farther between the endpoints.

The speed of transmission through fiber and other network media is finite, so physical distance creates a fundamental limit on how quickly data can move between locations.

This is why placing infrastructure closer to target users can be an important consideration for latency-sensitive applications.

Network Routing

The route selected between two endpoints can have a major effect on latency.

Traffic may pass through multiple carriers, routers, autonomous systems, and internet exchange points before reaching its destination. A shorter or better-performing route can reduce unnecessary delay compared with a less efficient path.

XLC’s network infrastructure uses multiple carriers, Tier 1 transit, internet exchange peering, and direct China connectivity to provide alternative routing paths for global and Asia-focused workloads.

Network Congestion

When a network link or device becomes heavily utilized, packets can spend more time waiting to be transmitted or processed. This queuing increases latency and can also make latency less consistent.

Congestion can therefore affect not only average latency but also p95 and p99 performance.

Network Hops

Traffic often passes through multiple routers and network segments before reaching its destination.

Each hop can introduce processing, queuing, or transmission delay. The number of hops alone does not determine latency, but unnecessary or inefficient intermediate routing can contribute to a longer network path.

Network and Server Processing

Routers, firewalls, load balancers, and other network devices can introduce processing delay.

Server-side processing is a separate factor: an application may respond slowly because the server takes time to process a request, even when the underlying network has low latency. This is why network latency and total application response time should not be treated as the same metric.

Latency vs Bandwidth vs Throughput vs Jitter

These metrics describe different aspects of network performance.

A network can have high bandwidth and high latency at the same time.

For example, a high-capacity connection between two distant regions may transfer large amounts of data efficiently while still taking longer to establish a response because of physical distance and routing.

Increasing bandwidth can improve throughput when capacity is the bottleneck, but it does not automatically shorten the physical or network path between endpoints.

This distinction is important when choosing dedicated servers. Server location, routing, carrier connectivity, and network architecture can be just as important as the available bandwidth when latency matters.

Why Does Latency Matter?

Latency matters most when an application depends on fast interaction between users, servers, databases, or other systems.

Online Gaming

Multiplayer games continuously exchange data between players and game servers.

Lower and more consistent latency can reduce the delay between a player’s action and the server response. High or unstable latency can make gameplay feel less responsive.

Ping is commonly used in gaming to describe a measured round-trip time, although technically it is the diagnostic method rather than a separate network characteristic.

XLC positions its gaming infrastructure around low-latency connectivity and direct Asia and China network reach for latency-sensitive multiplayer workloads.

Financial Services

Trading platforms, payment systems, and other financial applications can depend on predictable response times.

For these workloads, tail latency can matter alongside average latency because occasional delays can affect time-sensitive operations.

APIs and Web Applications

Latency affects how quickly an application receives a response from a remote service.

If an application makes several sequential network requests, the individual delays can accumulate and increase the overall response time.

Cloud and Hybrid Infrastructure

Applications that communicate between dedicated infrastructure and public cloud services can introduce additional network paths.

The quality of the connection between those environments can therefore affect application responsiveness, particularly for workloads that exchange data frequently or require low-latency communication.

XLC’s Direct Cloud Connect provides private connectivity between dedicated infrastructure and cloud platforms, with the aim of reducing latency and improving traffic consistency compared with public-internet paths.

Real-Time Applications

Latency is also important for video conferencing, interactive streaming, remote applications, voice communications, and other services where users expect near-real-time responses.

For traditional on-demand video, bandwidth and throughput may be more important than extremely low latency. For interactive applications, latency becomes more significant.

What Is Low Latency?

There is no single latency value that qualifies as low latency for every application.

The appropriate target depends on:

• application type;
• geographic distance;
• network architecture;
• user expectations;
• protocol;
• workload characteristics;
• required response time.

A latency level that is acceptable for a background data transfer may be unsuitable for a multiplayer game or real-time financial application.

The goal should therefore be latency appropriate to the application’s requirements, rather than an arbitrary universal threshold.

How Does Data Center Location Affect Latency?

Server location is one of the most important factors to consider when latency matters.

If most users are concentrated in a particular geographic region, placing infrastructure closer to that region can reduce the distance traffic needs to travel.

Location also affects the available carriers, internet exchanges, submarine cable routes, and connectivity options.

For example, an application serving users across Asia may benefit from infrastructure located within the region rather than routing traffic through a distant server location.

XLC currently lists data centers in Los Angeles, Tokyo, and Hong Kong, providing infrastructure options across North America and APAC.

However, geographic distance alone does not determine latency. The actual network route, carrier selection, congestion, and intermediate network infrastructure also matter.

How Can You Reduce Network Latency?

Latency cannot be eliminated completely because physical distance and network processing create unavoidable delays. However, network architecture can often reduce unnecessary latency.

Choose an Appropriate Server Location

Deploying infrastructure closer to the majority of users can reduce the physical distance traffic needs to travel.

Optimize Network Routing

Efficient routing and carrier diversity can help avoid unnecessarily long or degraded network paths.

Use Direct Connectivity

Private connections between infrastructure and cloud platforms can provide a more controlled path than routing traffic through the public internet.

Reduce Unnecessary Network Hops

Network architecture can be designed to avoid unnecessary intermediate systems where application and security requirements allow.

Use Regional or Multi-Region Infrastructure

Applications serving users across multiple markets may benefit from deploying infrastructure in more than one geographic region.

Monitor Tail Latency

Average latency can hide intermittent problems. Monitoring p95 and p99 latency can reveal spikes that affect a smaller percentage of requests but may still have a noticeable impact on users.

Does Higher Bandwidth Reduce Latency?

Not necessarily.

Bandwidth determines how much data a connection can transfer, while latency measures the delay involved in moving data between endpoints.

Increasing bandwidth can improve throughput when a connection is capacity-constrained, but it does not automatically reduce physical distance, change the route, or eliminate network congestion elsewhere in the path.

For example, upgrading a connection from 1 Gbps to 10 Gbps does not by itself reduce the latency between Los Angeles and Tokyo.

For latency-sensitive workloads, server location, routing, carrier connectivity, congestion, and network architecture may be more important than simply increasing port capacity.

How Should You Evaluate Network Latency?

When comparing infrastructure providers or server locations, a single advertised latency number is not enough.

Consider:

• User location – measure latency from the actual markets that matter to the application.
• Destination – latency to a nearby network endpoint may differ significantly from latency to end users.
• Measurement method – ping, RTT, TTFB, and application response time measure different aspects of performance.
• Average and tail latency – p95 and p99 can reveal instability that averages hide.
• Network route – examine carriers, transit providers, peering, and intermediate hops.
• Time of measurement – network conditions can change with traffic levels and routing events.
• Application architecture – database calls, API requests, and sequential network operations can add to total response time.

For production infrastructure, testing latency from the locations that matter to the application is more useful than relying solely on a generic provider claim.