yes Ethernet over USB. I have found a partial solution: put in only charge mode so no module is loaded and from shell load module g_ether, so I have only CDC-ECM, but the protocol is 255 and not 3 (RNDIS), so for Windows driver is required, but I need Windows automatically configure it without human interaction.
Recently I see some projects on Raspberry Zero as usb gadget and CDC-ECM, so I would to replicate it on N900 without buy Raspberry Zero.