Teramind Agent uses approximately 10 KB/s - 20 KB/s bandwidth depending on user activity level & number of screens. You can configure how much bandwidth is used and when from the settings.
You can also configure Teramind to run at a reduced frame rate and color palettes, and that would cut back bandwidth and storage consumption significantly. For more information on how to reduce bandwidth and storage use, check out this article: How to reduce storage requirements.
Teramind also detects if the connection is poor, and will dynamically reduce the frame rate accordingly to minimize bandwidth usage.