Differenciate Multiple USB Ports

[kanhu]

Hi all,

Can anybody help me on how to differenciate multiple usb ports on a 
system running fedora core 3.
Is there any commands available to know this.
ls -all /dev/ttyUSB shows me

ttyUSB0   ttyUSB10  ttyUSB12  ttyUSB14  ttyUSB2   ttyUSB4   ttyUSB6   
ttyUSB8
ttyUSB1   ttyUSB11  ttyUSB13  ttyUSB15  ttyUSB3   ttyUSB5   ttyUSB7   
ttyUSB9

Currently I am using only one USB port for my mouse.
I have pluged in the Usb-To-Serial converter  on one of my USB PORT, And 
try to configure it by minicom -s
it shows me

minicom: cannot open /dev/ttyUSB0: No such device or address

I have tried it for USB0,USB1,USB2.......

Any Idea to proceed is welcome


With Thanks & Regards
      Kanhu