After working in cloud infrastructure, it became about 50/50 whether I'd check hardware or software logs first - usually leaning whichever way I thought had better diagnostics in the problematic area. Document as much as you can about the software symptoms of the hardware fault - someday someone will thank you.

Microsoft has documented a significant portion of their protocols for interoperability. The same is unlikely to be true for the others (at the time of this writing) and the previously suggested network capture is likely your best bet. To get you started, you can see an example of a Microsoft protocol document detailing BITS upload of large files to OneDrive. https://msdn.microsoft.com/en-us/library/dn858877.aspx You can search from there for other protocol documents, including BITS itself.