I'm talking about the "Speedtouch Home/Pro" which I got cheap from a friend.
Until now I've used it in bridging mode which is simplest but not available with my new provider: they use Tel$tra infrastructure and therefore require PPPosomething. Which I don't like at all, that being an ugly hack "solution".
So I need to run some PPPoA thingie somewhere, not on my firewall please, and I need my static IP be routed to my firewall.
The alcadreck is not a nice router, ut it has one redeeming feature (if you can get it to work): it can run into something they call "SIP Spoofing" mode and what I'd simply call an unnumbered PPP interface.
Then the black magic begins: you setup a PPP config called "SIP_SPOOF", give it a weirdish IP address for the local PPP end, add a route for your official static IP to the actual modem ethernet IP. Then you hope, and maybe it works. If not, you're none the wiser because the POS has no useful logging or debugging support.
The magic is described here; what I've found out the hard way is that the local PPP address must not be a rfc1918 address, and it also must not be "none". In the first case, PPP doesn't come up; in the second you lose all connectivity to your modem on the ethernet side.
I think I'll have to look at ebay for something a bit less sucky than this box.