What is Latency & How To Fix Network Latency Issues?

Network performance matters for businesses and individuals alike. Latency, often called "lag", is one of the biggest factors behind slow websites, choppy video calls and delayed app responses.

In this article, we explain what latency is, what causes it, how it affects website speed, and practical ways to reduce it for your network and your website visitors.

What is Latency?

1. Definition:

• Latency is the time it takes for data to travel from its source to its destination across a network. It is measured in milliseconds (ms). Often it is measured as round-trip time: the time for a request to reach a server and the response to come back.

2. Latency vs Bandwidth:

• Bandwidth is how much data can flow at once; latency is how long each trip takes. A connection can have high bandwidth and still feel slow if latency is high, because every request and response has to wait for the round trip.

3. Types of Latency:

• Network Latency: The delay within the network itself, including distance, routers, switches and transmission media.
• Server Latency: The delay while the server processes the request and prepares a response, for example running database queries.
• Application Latency: The delay introduced by the application on the server or on the user's device, such as heavy JavaScript in the browser.

Causes of Network Latency

1. Distance: Data can't travel faster than light through fibre. A visitor in Pakistan loading a site hosted in North America waits longer for every round trip than one loading a site served from a nearby location.

2. Network Congestion: High traffic volume causes congestion, and data packets wait in queues before they are sent.

3. Hardware Limitations: Older or underpowered routers, switches and Wi-Fi equipment can add delays.

4. Data Packets and Routing: The path packets take, including the number of hops between routers, affects latency. Traffic is not always routed along the shortest physical path.

5. Bandwidth: When a link is saturated, for example by large uploads or downloads, other traffic has to wait, which raises latency.

6. Connection Setup: Each new connection needs DNS lookups and connection and encryption handshakes before any data flows. On high-latency links, these extra round trips add up.

How to Measure Latency

1. Ping Test: A simple command-line tool that sends a small packet to a destination and measures how long the reply takes.

2. Traceroute: A diagnostic tool that shows the path packets take to reach their destination, and where along the route delays occur.

3. Network Monitoring Tools: Monitoring software gives real-time and historical data on latency, packet loss and jitter across your network.

4. Browser Developer Tools: The Network panel in Chrome or Firefox shows timings for each request on a web page, including DNS lookup, connection, TLS setup and waiting time for the server's response.

5. PageSpeed Insights and Lighthouse: These free Google tools report Time to First Byte and other speed metrics, using real-user data where available.

Latency and Website Speed

For websites, latency directly affects how quickly pages start to appear. Three concepts matter most.

1. Time to First Byte (TTFB):

• TTFB measures the time from the start of a request until the first byte of the response arrives. It includes redirects, DNS lookup, connection setup and server processing. According to web.dev, good TTFB values are 0.8 seconds or less and poor values are greater than 1.8 seconds, as a rough guide.
• A slow TTFB delays everything after it, including your Core Web Vitals such as Largest Contentful Paint.

2. Content Delivery Networks (CDNs):

• A CDN stores copies of your site's files on servers in many locations and serves each visitor from a nearby one. This shortens the distance data travels and is one of the most effective ways to cut latency for visitors spread across cities or countries.

3. HTTP/2 and HTTP/3:

• HTTP/2 lets a browser send many requests over one connection, avoiding repeated connection setup.
• HTTP/3 (RFC 9114) runs over QUIC, a transport built on UDP. It combines connection and encryption setup and avoids one lost packet holding up all other requests on the connection. This helps most on mobile and less stable networks.

How to Fix Network Latency Issues

1. Optimize Network Infrastructure:

• Upgrade Hardware: Replace old routers, switches and Wi-Fi access points that can't keep up with your traffic.
• Reduce Distance: Host your website close to your main audience, and use a CDN to serve visitors from nearby locations.
• Network Design: Keep the network design simple, with minimal hops and efficient routing.

2. Increase Bandwidth:

• Upgrade Bandwidth: Increase capacity if links are regularly saturated.
• Traffic Management: Use Quality of Service (QoS) policies to prioritize critical traffic, such as voice calls or point-of-sale systems.

3. Minimize Network Congestion:

• Load Balancing: Spread traffic across multiple servers or network paths.
• Peak Traffic Management: Schedule backups and other bandwidth-heavy tasks for off-peak hours.

4. Optimize Software and Applications:

• Caching: Cache pages and data on the server, in the CDN and in the browser, so fewer requests need a full trip to the origin server.
• Compression: Compress text files (for example with Brotli or gzip) and use modern image formats to reduce transfer size.
• Fewer Requests and Redirects: Remove unnecessary redirects, third-party scripts and requests. Each one adds round trips.
• Faster Server Response: Optimize database queries and use server-side caching to reduce processing time and improve TTFB.

5. Use Modern Protocols:

• Enable HTTP/2 and HTTP/3 on your hosting or CDN, and TLS 1.3 for faster secure connections. Many CDNs offer these as simple settings.

6. Regular Monitoring and Maintenance:

• Network Monitoring: Track latency and TTFB over time so you catch problems before users complain.
• Regular Updates: Keep network equipment firmware and server software updated for performance and security.

Conclusion

Latency is a critical factor in network performance and user experience. Distance, congestion, hardware and connection setup all add delay.

For networks, better hardware, sensible traffic management and monitoring make a clear difference. For websites, a CDN, caching, fast server responses and modern protocols like HTTP/3 reduce latency for every visitor.

Boost Your Network Performance with Expert Solutions!

Softhat builds fast websites for businesses across Pakistan, with CDN, caching and server tuning that keep response times low. Explore our web development services, or book a free strategy call to find out what is slowing your site down.