Fibre optic, copper, throughput speeds, ADSL and more. If you're confused by broadband terms, we can help.
Broadband is something millions of us use every day to stay in touch, work and play, using laptops, tablets and phones. Speeds available to you vary depending on many factors, including the technology and your location
What is sync speed?
Sync speed is the speed between your BT Hub and your local telephone exchange. It's sometimes called 'line rate'. Sync speed can depend on the distance from the cabinet or exchange and whether microfilters are installed correctly.
What is throughput speed?
Throughput speed is the speed at which your broadband can actually send and receive data between the internet and your BT Hub. It's what you experience at home when using your broadband connection. It can't be higher than the sync speed. It can vary throughout the day and can be slower during busy periods, especially between 8-10pm. This is the equivalent of the internet rush hour when lots of people are using the shared parts across the network at the same time.
If you run our speed tests in the Troubleshooter or My BT app, we'll show the throughput speeds to your BT Hub.
This may be different to the speed you receive on your device, which is affected by a wide range of factors. Things like the number of devices connected to your Hub at the same time and whether you're using wi-fi or a wired connection.
To see what broadband speeds you can get see Test your BT Broadband speed >
How are broadband speeds measured?
Broadband speeds are measured in megabits per second or Mbps. Each megabit is made up of 1,000,000 bits or 1,000 kilobits. The more megabits, the faster your broadband.
Faster broadband speeds means faster downloads. You can download music and movies quicker, stream from services like Netflix without waiting, and make video calls more smoothly.
The table below shows the minimum broadband speeds you need for some common activities.
Minimum broadband speed needed
|Web browsing||1 Mbps (download)|
|HD video streaming||5 Mbps (download)|
|Ultra HD video streaming||30 Mbps (download)|
|Voice over IP||256Kbps (download and upload)|
|Real time online gaming||256Kbps (download) and 512Kbps (upload)|
|Video calling||1 Mbps (download and upload)|
How do broadband speeds work?
Broadband typically comes into your home through your telephone line. There are two main types of cable for doing this - copper or fibre optic - with different connection speeds.
Copper: This is used to deliver ADSL and ADSL2+ broadband from the telephone exchange to your house. The longer the length of copper, the weaker the signal strength and the slower your broadband line will have to operate.
Fibre optic: Faster than copper, there are two ways fibre optic broadband can get into your house.
- Fibre to the Cabinet (FTTC) In traditional fibre, fibre optical cables run from the telephone exchange to the street cabinets. Copper cables are then used to connect the cabinet to your house. The maximum broadband speed you get depends on the distance from your house to the cabinet. The closer you are from cabinet to home, the faster your broadband.
- Full Fibre - sometimes called Fibre to the Premises (FTTP) or Fibre to the Home (FTTH) Here you get a dedicated fibre connection directly to your house. Your maximum broadband speed isn’t dependent on distance, so you can get the fastest speeds. FTTP provides the most reliable broadband connection.