Network Latency: What It Is and How to Actually Reduce It

Latency is the time it takes for a packet to travel from source to destination. Bandwidth is how much data you can send per second. People confuse them constantly — 'my internet is slow' usually means one of two completely different problems that require different solutions. Latency is the one that makes games unplayable and video calls choppy. No amount of extra bandwidth fixes it.

The Physics of Latency

Light travels through fibre optic cable at about 200,000 km/s — roughly two-thirds the speed of light in vacuum. London to New York is about 5,500 km by cable. Minimum possible latency for a single trip: about 28 milliseconds. Round-trip: about 56ms. A well-run direct fibre link actually achieves close to this theoretical minimum.

The actual round-trip time you see on a ping from London to New York is typically 70-90ms. The difference from the theoretical minimum comes from processing delays at routers, queuing when links are congested, and the cable not running in a perfectly straight line.

The Different Types of Latency

Propagation delay is the physics — distance over speed of light. This can't be reduced without moving the servers closer to users (which is exactly what a CDN does). Processing delay is how long routers take to forward packets — microseconds to milliseconds per hop. Queuing delay happens when links are congested and packets wait in buffers — this is where most latency variability (jitter) comes from.

Bufferbloat is the underdiagnosed culprit in most home latency complaints. When your connection is saturated, packets pile up in the router's buffers waiting to be sent. This adds tens to hundreds of milliseconds of latency to everything. You notice it as the internet feeling sluggish when someone on your network is downloading something. The fix is active queue management (AQM) — look for CAKE or FQ-CoDel on your router's settings.

What Actually Reduces Latency

Using servers geographically close to you is the biggest lever. For gaming, connect to servers in your region. For remote work, use a corporate network with presence in your country. For web browsing, a CDN automatically handles this.

A wired Ethernet connection over Wi-Fi reduces latency and jitter significantly — wireless adds overhead and is more susceptible to interference. A quality router with modern queue management handles congestion without bufferbloat. A VPN adds latency — the extra hop to the VPN server adds 5-50ms depending on its location.

Measuring Your Own Latency

Ping is the simplest latency measurement tool — it sends ICMP Echo Requests and measures round-trip time. 'ping 8.8.8.8' gives you latency to Google's DNS server. But ping measures ICMP traffic, which routers often deprioritise. For actual application latency, connect to the specific service you care about and measure at that layer. Gamers measure latency to game servers. VoIP users measure latency to the closest media relay. The ping to Google tells you something about your general network health, not specifically about why your game server feels sluggish.

Jitter is as important as latency for real-time applications. Jitter is the variance in latency — if your connection to a game server has 50ms average latency but it swings between 30ms and 200ms unpredictably, the experience will feel worse than a consistent 80ms. Tools like iPerf3 measure both latency and jitter accurately. For gaming specifically, the game's own built-in ping display reflects the actual gameplay latency including any server-side processing — more relevant than a raw network ping.