help with Rb953GS usb bus

RouterOS General
1

how can I know on which usv bus I’m using ?

 2:1    Linux 3.3.5 ehci_hcd                                            RB400 EHCI                                                   480 Mbps                                                     
 1 1:1    Linux 3.3.5 ehci_hcd                                            RB400 EHCI                                                   480 Mbps                                                     
 2 2:6    Sierra Wireless, Incorporated                                   MC7710                                                       480 Mbps

does it mean that the MC7710 usb bus 2 ? because it say 2:6?
and if was on bus 1 is would say 1:6 ?

Thanks ,