How to Run an Internet Speed Test (and What the Results Actually Mean)

To run an internet speed test properly, connect a computer to your router with an Ethernet cable, close everything else using the connection, and run the test three or four times at different points in the day — then compare download, upload, latency and jitter against what your plan promises. The headline download number gets all the attention, but for a business running VoIP phones and cloud apps, latency and jitter usually matter more. This guide covers how to get a result you can trust, and what to do when the numbers come back poor.

How to run a speed test you can trust

Most speed test complaints fall over at the first hurdle: the test was run over Wi-Fi, on a busy network, once. That tells you almost nothing. To get a result worth acting on, plug a computer directly into your router with an Ethernet cable. Wi-Fi adds its own bottlenecks — distance, interference, too many devices on one access point — so a wireless test measures your Wi-Fi, not your internet connection.

Before you start, close anything that uses the connection: cloud backups, video streams, large downloads, and file sync tools like OneDrive quietly working in the background. If you share the connection with other staff, run at least one test before they arrive or after they leave.

Run the test three or four times, and repeat the exercise at different points in the day — first thing, midday, and mid-afternoon. A single result is a snapshot; a pattern is evidence. Use a reputable browser-based test and choose a test server in New Zealand, ideally Auckland, so you are measuring your connection rather than an undersea cable. Screenshot every result. If you end up in a fault conversation with your provider, dated results from a wired connection are what get taken seriously.

What download and upload speeds actually mean

Speed tests report download and upload in megabits per second (Mbps). Download is data coming to you: loading web pages, streaming video, pulling files from the cloud, installing updates. Upload is data leaving your network: sending email attachments, backing up to the cloud, syncing SharePoint libraries, and — critically — your side of every video call.

Home-style thinking treats upload as an afterthought, and many plans are still asymmetric, with upload a fraction of download. Modern businesses do not work that way. A team on Microsoft 365 with cloud backup and daily video meetings pushes a surprising amount of data upstream. When calls break up every afternoon at the same time a backup job kicks off, a saturated upload is the usual suspect.

Check what your plan actually promises before judging the numbers. A wired result consistently well below the advertised speed is worth pursuing with your provider. A result close to plan that still feels slow points to a different problem — often one of the numbers below.

Latency and jitter: the numbers that decide call quality

Latency, often shown as "ping", is the round-trip time for a small packet of data, measured in milliseconds. Jitter is how much that time varies from packet to packet. Neither matters much for email or web browsing, but together they decide whether real-time traffic — voice and video — works or falls apart.

A phone call over the internet cannot buffer the way a streaming video can. If packets arrive late, out of order, or not at all, you get the familiar symptoms: robotic audio, people talking over each other, frozen video, dropped calls. As a working rule, you want latency well under 150 milliseconds and jitter under about 30, and lower is always better — a healthy fibre connection to a local test server should sit comfortably inside those figures.

If your business runs its phones through Teams calling or a cloud PBX, latency and jitter deserve more attention than headline speed. A modest connection with low, stable latency will deliver better calls than a fast connection with erratic timing.

Why your results don't match your plan

When a wired test at the router comes back fine but the office still feels slow, the problem usually lives inside your own network. Common culprits include an ageing consumer-grade router that cannot keep up with a fibre connection, badly placed or overloaded Wi-Fi access points, tired cabling, and VPNs that route all traffic through a distant server before it reaches the internet.

The device matters too. An older laptop's network card or a cheap Wi-Fi adapter can cap results well below what the connection delivers, so test from two or three devices before concluding the connection is at fault.

The useful diagnostic habit is isolation: test wired at the router, then wired at a desk, then over Wi-Fi in the areas where people actually work. Where the numbers fall away tells you where the problem is.

When to escalate — and what evidence to bring

Escalate to your internet provider when wired tests, run at different times over several days, consistently come in well below plan — or when latency, jitter or packet loss stay persistently poor. Bring the evidence: dated screenshots, confirmation the tests were wired with nothing else running, your router make and model, and which test server you used. That homework turns a "have you tried restarting it" conversation into a fault investigation.

If the provider checks the line and reports it healthy but staff are still complaining, the fault usually sits in the internal network — and that is not the provider's job to fix. This is where a proper business internet and networking review earns its keep: looking at the router, switching, Wi-Fi design and cabling as one system, rather than blaming the connection by default.

Building a connection that tests well every time

A good result today does not guarantee one next month. The businesses that avoid connectivity dramas tend to do a few things consistently: choose a plan sized for their upload as well as their download, run business-grade routing with quality-of-service rules that protect voice traffic, and keep a baseline of test results so "the internet is slow" can be measured rather than debated. Many also add a 4G or 5G mobile broadband backup so a fibre outage becomes an inconvenience rather than a lost day.