Upload files using .Net SDK

Hi Box community,

I am writing a tool to upload the content of a folder to BOX. I start with this example:

https://developer.box.com/guides/uploads/chunked/folder/

I modified it not to start task in parallel but to do it sequentially.

As probably you know, in the .Net SDK there are 2 functions to achieve it depending on the size of the files:

1) FilesManager.UploadAsync   (size < 20Mb) 

2) FilesManager.UploadUsingSessionAsync (size > 20Mb) 

I am compressing the files using 7z and then splitting them in parts.

Doing some testing I have noticed that when I uploading files using function 1 (UploadAsync ), the success rate is very low and I get a lot of these exceptions:

1) Error: Error while copying content to a stream.      (more frequent)

2) An error occurred while sending the request.         (less frequent)

I have created a while to retry the failed uploads and took me 20 retries to upload 6 parts (10Mb) of a 7z archive.

It seems that using a timeout has improved the successful transfer rate for bigger files, but not fix the issue for the smaller ones. 

Additionally, it seems that the successful transfer rate drops for files bigger than 500Mb. Do you have any suggestions? 

Cheers,

Francesco