Does it matter is if use the USB or Ethernet port on the modem ?
Some DSL modems carry USB capability. This is useful alternative in instances where a network card cannot be installed. Please note that you cannot use the USB port of a usb HUB to extend the wire length between your modem and PC, or share the access to multiple systems. You can use the USB and Ethernet ports at the same time to facilitate access on two machines provided the advanced modem routing features are enabled.