D-Link DSL-504T ADSL Router D-Link product page
There might be Annex B (ADSL over ISDN) versions around, please add them to this table if you're able to find them. They should work, though.
The same board is probably used for the wireless-enabled DSL-G604T.
NOTE: AR7 modems have a reputation of running HOT and the 504T is no exception, so if you're planning to run it for any lenght of time, attaching an heatsink to the CPU might be a good idea.
Relevant forum threads:
DSL-5xx general info:
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