USB Host-Host cables

[Richard Owlett]

I have purchased a USB Host-Host cable based on the PL-25A1 chipset.
Where would discussion about using it be *ON TOPIC* ?
It is recognized by Debian Stretch.
I have found relevant bits-n-pieces in manpages and package info.
I'm retired and my avocation is learning about Linux.
I'm missing background in:
   USB interfacing
   networking (in a broad sense)
TIA