I have a 5d mark 2 and i used to work the usb live shooting but i have destroyed the usb
I recommend upgrading the camera. You might still be able to get the 5D2 repaired by Canon Service. But, think you're probably better off investing in one of the newer cameras that incorporates Bluetooth.
Yes, I believe that you can use the Ethernet port to hard wire to a LAN, which is the real purpose of the accessory. Wireless files transfers over Wi-Fi always seem to be slower than copper connections when it comes to older DSLRs.