You don't seem too confused. That's an answer and looks viable.
I may have mis-interpreted what I read, but I have script running mssql_* functions from a couple years ago. We recently updated the underlying OS, and in so doing all 3rd-party software and libraries were updated. SQL Server on the Winbox reported "Connection opened but invalid login packets sent" --- a little more searching revealed that the driver was "packet flooding" the server, (trying to remember the correct term) near as I can tell, so I'm looking for an alternate means (driver?) to test with.