9 seriel ports on the WR21

Hi,

I am wondering why you are able to configure 9 serial ports on the WR21, Serial 0 is always the physical port, but what is the rest used for - virtual ports, or a kind of “serial port HUB”

Thanks
Martin

The others are used by usb serial /GPS and cellular modules

and to follow other models like wr44 with 3 extra serial and other daughter cards