Which is better for DSL, Ethernet or USB modem?

• Ethernet connection are more reliable compare to USB based interface.
• Ethernet means easier to expand the network or add a wireless router at later date.
• Ethernet modems also avoid the problems of configuring port forwarding and getting applications to work from behind a NAT router.
• If you intend to use router you must use Ethernet for the modem to router connection.
• USB is used to connect your computer to a wide variety of devices. An Ethernet interface, on the other hand, is intended for network traffic only. It connects directly to the computer's bus so that high speed transfers occur with the lowest possible CPU overhead.

The Ethernet interface is usually preferred for DSL connection as this frees your USB ports (and bandwidth) for other peripherals.