Is your internet connection driving you mad? Here’s what might be behind it

For most people, diagnosing a dodgy internet connection is nigh on impossible. After all, the internet is a complex hodgepodge of hardware and software, and the odd jumpy Zoom call is often accepted as an inexplicable feature of a network we don’t well understand.

But internet connection issues are actually quite easy to explain. They arise when the flow of data along internet cables is interrupted, most frequently when the demand to use the cables is very high. That’s why your connection seems worst during “peak TV viewing” hours, when everyone’s trying to stream videos using the same cables at the same time.

And while modern fiber-optic cables lead to faster internet speeds, it’s likely that we’ll always experience frustratingly slow internet from time to time. It’s a byproduct of a network that’s built to be flexible – and the finite load of the cables that support it.

The physical network

The internet is a network of cables that send digital data across vast distances at close to the speed of light. Between countries and continents, the internet is distributed via a vast series of undersea cables. Within countries, smaller cables run underground until they eventually branch into each of our homes.

In the UK, BT and Virgin Media are the major cable infrastructure providers. It’s they who physically plug the internet into UK homes, and they’re also responsible for laying and updating the underground cables that carry your data around the country or to the undersea cables to go further afield.

Some homes have “fiber to the premises” (FTTP) connections, connecting homes directly to fiber optic cables which can carry digital data incredibly quickly. But most UK homes have “fiber to the cabinet” (FTTC) connections, which are a little slower.

These deliver a high-speed fiber optic connection to local internet cabinets, from where slower copper wires run the “final mile” to surrounding homes. Copper can only carry analog signals, so digital data has to be continually converted to analog in homes that are connected to the internet via copper wires.