I apologize if this isn't the most appropriate forum.
My isp, ya.com in spain, supplies an smc wireless router. It's called SMC-7908-ISP, has a customized version of the firmware and there's virtually no documentation available on the net. It has an adsl port, a 4 port ethernet switch, wireless and 2 FXS ports.
I opened it and took some photos, unfortunately the main chip is covered with a glued-in heatsink.
As you can see in the wireless chip is an atheros 2417 (3rd photo), the switch is a realtek (2nd photo) and there's not much else there.
I suppose it's a danube because the firmware file (that I cannot decipher) it's called "ya.com-FW-1.00.001(danube-AnnexA-ISDNx-FXOx-USB).bin", and there are references to DANUBE inside (e.g. there's an embedded zip file with a "DANUBE_184.108.40.206.0.1.bin" file).
On the second photo you can see a J2 header that's probably a serial port.
Do you think it's really based on the danube chipset? If so it should be possible to run openwrt on it, though I won't have the possibility to experiment too much since the device will be providing my main phone line (through its FXS ports).