CrankWheel will try to adapt to almost all networking situations you are likely to encounter in the modern day.
The absolute minimum for the viewer is GPRS EDGE bandwidth, which is about 236 kbit/s, i.e. extremely slow. Down to this speed, CrankWheel should work, but screen sharing delays can be several seconds and the initial load for the viewer might be around 20 seconds.
Any 3G connection speed or better for the viewer will work absolutely fine.
For the presenter, we recommend a reasonably fast ADSL connection or better, but 3G or higher connection speeds should work fine.
If you have questions, don't hesitate to contact us.