you for your interest in the RadUpload for Silverlight
About large files.
All files are uploaded by chunks (default chunk size is 100'000 bytes but you
can change it). Because of this there are no problems with large files - we
already tested the control with a 4 GB movie.
About upload resuming.
Till now we do not implement it. Probably it will be available in the incoming Q3 release.
More information about the RadUpload you can find in links below:
We hope this information will help you.
All the best,
the Telerik team