Whenever you use the internet you cause network traffic ("use data") whether it's reading a web page, sending an email or watching video.
If you usually use the internet to browse websites and check your email, you'll probably only use 1-3 GB each month. This will give you very approximately 30 hours of intensive web browsing, plus enough data to download 50-100 songs.
If you watch a lot of video or download a lot of music, you will use more than this.
To give you a very rough idea of how much traffic you're using:
- visiting a website uses less than 1 MB of traffic
- a four minute song uses about 6 MB
- a five minute YouTube video could use up to 15 MB
- installing software updates will use 50 to 500 MB each month
- watching iPlayer, 4oD or similar for an hour uses about 700 MB
- downloading a high-definition film or 3D game could use 5 GB
(One gigabyte (GB) equals 1024 megabytes (MB).)
You can always track your usage here on this website. If you are using more traffic than you expect, you should check for running peer-to-peer applications such as BitTorrent and consider in particular your usage of video streaming services such as iPlayer, 4oD, Skype video, etc.. Additionally use of cloud backup such as Dropbox, OneDrive, Google Drive, iCloud, etc may generate significant traffic depending on what you sync to such services.
If you believe that your usage has been recorded incorrectly, please raise a service request with the IT department. If you have an academic reason for using additional network traffic, please also raise a service request; we may be able to waive charges in some such situations.