It was a preliminary scan of the Tello. Playing with it a little more, it looks like what I'm seeing is an Abyss Web Server on port 9999. I have also discovered it has a Guava Bluetooth device. You can see this by removing the battery, holding down the power button and then plugging in the micro USB to a PC. It only pops up briefly. My PC recognized it and installed the drivers but only connects briefly. Great little drone to play with.