How it works

There are three layers between you and the wider internet, and any of them can be the source of an issue:

1. The line — fibre, copper, or wireless from us to a box at your home.
2. Your router — the box that turns that line into a network for your devices.
3. Wi-Fi or cable — how each device reaches that router.

A speed test on a phone at the back of the house touches all three. When something is slow, narrowing down which of the three is the problem is half the work.

The line is what we sell you — it has a fixed speed (e.g. 100 Mbps). Wi-Fi is something else entirely: a radio link between your device and the router, shared with every other Wi-Fi network nearby.

A 100 Mbps line will not magically push 100 Mbps over Wi-Fi to a phone two walls away. Wi-Fi can be the bottleneck even when the line is perfect.

The fastest way to test which one is the problem: plug a device in with a cable. If wired is fine and Wi-Fi is slow, the line is fine — Wi-Fi is the issue.

Streaming services adjust quality on the fly based on how fast they are receiving data. Buffering happens when the data slows or pauses. Common reasons:

• Wi-Fi reach — most common. Move closer to the router, or use a wired connection.
• Other devices using the network — large downloads, cloud sync, someone else streaming in 4K.
• Their server — when a hit show launches, even Netflix has busy moments.
• Peak hours — see below.

A buffering problem that only happens in one room is almost always Wi-Fi-related, not a line problem.

The internet is shared. So is the network we use to reach it. Between roughly 19:00 and 22:00, demand is at its highest — millions of homes are streaming at the same time. Even a healthy line can feel a touch slower during this window.

This is normal and is not the same as a fault. If your speed is poor all day that is a different problem and worth reporting. If it is only slow in the peak window and fine outside it, that is congestion, not a broken line.