Supports all the features of the SpeedTouch? Home/Pro but has the addition of DHCP spoofing and a default internal IP address to send all requests for external ports to.

DO NOT USE THE DHCP SPOOFING WITH LINUX, it is very broken!, causes default gateway to go to a random number about once a month and messes with resolv.conf putting in incorrect name servers.

The main advantage of the (Thompson, once Alcatel) SpeedTouch? 510 is UniversalPlugAndPlay, a new standard supported by Windows XP that means you can see the DSL modem in your "network connections" tab, and automatically set up NAT pin holes for things you run on your UPNP client.

Turn it off. Its broken, you really don't want it, they don't recommend you use it yet.

That, and the web interface sucks. Most config can only be done through an upload of a config file. You can flash a 510 to a Pro, save yourself a lot of effort and stress.