Solarwinds Free SFTP/SCP Server concurrent sessions/connections/transfers, etc.

Hey guys, we’re evaluating your free SFTP/SCP Server software and I was wondering if you could answer the question as to whether the software has a limit on concurrent connections, transfers, or downloads?  There doesn’t seem to be any documentation describing these parameters…and trying to figure out if a user having problems, if it’s them or the software.   I don't suppose there's anywhere to configure these parameters either?