While circumstances can vary from network to network the general rule of thumb is as follows:
Have twice the amount of upload bandwidth available as you will need for your stream. Go to speedtest.net to determine your upload speed.
- Example: If you want to stream a video at 1.5mb you would want (at the minimum) 3mb of upload and more will only help.
SD Video (480p): At least 1.5mb of upload speed.
HD Video (up to 1080p): At least 4 mb of upload.
Bear in mind that your upload speed is the most important factor in streaming video but it is not the ONLY factor. Equipment in your network setup (ethernet cables, switches, routers, modems) all play an important part in reliably delivering video data.
Check out this video for more information!