Glossary Term
Latency

Latency measures how long it takes data to travel from one point to another across a network. In internet services, it is commonly measured as round-trip time (RTT)—the time a data packet takes to reach its destination and return. Latency is measured in milliseconds, and lower latency generally means a faster response. It is different from bandwidth: bandwidth describes how much data a connection can carry, while latency describes how long it takes for data to make the trip. A business connection can have high bandwidth and still feel slow if latency is high.

For mid-sized and enterprise businesses, latency can affect daily work across offices, cloud platforms, and remote employees. High latency may cause delayed responses in cloud applications, awkward pauses in video meetings, talk-over during VoIP calls, or lag when employees access files and systems hosted elsewhere. Latency is influenced by physical distance, the type of connection, network congestion, routing, and the processing time of network equipment. Because remote employees connect through their own internet providers before reaching company systems, their experience can also depend on their home network and the route to the business application.

Businesses should consider latency when evaluating internet access, especially when they rely on real-time communications, cloud software, remote access, or applications hosted in specific locations. A provider like Fusion Connect considers latency as part of network performance and service design. Its SD-WAN offering uses dynamic path selection based on factors including latency, packet loss, and jitter, helping route application traffic over a better-performing connection when multiple paths are available.

Fusion Connect also offers an Internet Quality Test that measures latency alongside other connection-performance factors. Latency cannot be eliminated, but the right network design, monitoring, and routing can help reduce unnecessary delays and improve the experience for employees and customers.

How Does Latency Work?

When a device sends information over the internet, the data travels through network links and equipment before reaching its destination. The destination may send a response, which travels back to the original device. The time involved is latency.

Several factors contribute to network latency:

• Propagation delay: The time it takes a signal to travel over a physical distance. Data cannot travel faster than the speed of light, and signals move more slowly through fiber or other media than through a vacuum.
• Transmission delay: The time needed to place the data onto a network link. Packet size and connection capacity affect this delay.
• Queuing delay: The time data spends waiting in network equipment when traffic is busy or a link is congested.
• Processing delay: The time routers, switches, firewalls, and other systems take to inspect or forward data.
• Routing and retransmission: The path data takes and the need to resend lost or delayed packets can add more time.

These delays can accumulate across a network path. The farther data travels and the more network devices it passes through, the more opportunities there are for delay.

Latency, Bandwidth, and Jitter: What's the Difference?

These terms describe different aspects of network performance:

• Latency: How long it takes data to travel between endpoints and back.
• Bandwidth: The maximum amount of data a connection can carry over a given time.
• Throughput: The amount of data actually transferred successfully over time.
• Jitter: How much latency varies from one packet to the next.
• Packet loss: The percentage of data packets that fail to reach their destination.

A useful analogy is a road. Bandwidth is the number of lanes, throughput is how many cars actually pass through, latency is how long a car takes to reach its destination and return, and jitter is how inconsistent those travel times are.

For business voice and video, both latency and jitter matter.
A connection with low average latency but highly variable delays can still produce choppy calls or uneven video.

A Brief History of Latency

Latency is not a new internet problem. It is a fundamental property of communication: every signal takes time to travel, and every system takes time to process information. Early telecommunications networks dealt with delays in electrical signals, switching equipment, and long-distance transmission. As computer networks developed, latency became an important way to describe the responsiveness of data communications.

With the growth of packet-switched networks and the internet, engineers needed reliable ways to measure how long packets took to travel between computers. Tools such as ping made it possible to send a test packet and measure its round-trip time. Network measurement and performance engineering grew more sophisticated as businesses began depending on internet-based applications, voice communications, and distributed systems.

Today, latency is a key performance measure for business internet and cloud networking. The shift toward cloud applications, video collaboration, remote work, and real-time services has made network responsiveness important alongside bandwidth and reliability. Modern networking technologies, including SD-WAN, can monitor latency and other link conditions to help select a suitable path for application traffic.

Three Fun Facts About Latency

1. The speed of light still has a commute.
   Even though data travels through fiber-optic cable as light, it takes time to cross long distances. A network connection between faraway cities has a physical minimum delay that no router upgrade can completely remove.
2. More bandwidth doesn't always mean less lag.
   A connection can have plenty of capacity but still respond slowly if data has to travel a long distance or wait in a congested queue.
3. A few milliseconds can matter.
   For a large file download, a small delay may be barely noticeable. During a live conversation, however, that same delay can make people talk over each other—as if everyone suddenly forgot how to take turns.

Why Latency Matters to Business

Low latency helps business applications feel responsive. Employees can work more smoothly in cloud platforms, collaborate through voice and video, access hosted systems, and interact with customers without unnecessary delays. For organizations with multiple locations or remote employees, latency can affect how efficiently teams use shared applications and communicate across the business.

Latency should be evaluated alongside bandwidth, packet loss, jitter, and uptime—not as an isolated number. A business should test performance to the applications and locations it actually uses, including during busy periods. Managed networking and SD-WAN may help by monitoring connection quality and directing traffic over suitable paths. While a provider can help optimize the network, the performance of a remote employee's connection may also depend on their home internet service, Wi-Fi, device, and the location of the application they are accessing.