Do you have a BRI ISDN line to hook it up to? Phone companies in the US have long since stopped offering the service to new customers. Might not be worth the hassle.
No I don’t all that is long gone here in NZ, but the card has an Ethernet port so I thought I might be able to use it as an Ethernet device? Would this make sense?
Just because it's RJ-45 doesn't mean it's Ethernet! ISDN, confusingly, can also use RJ-45 jacks and transmit over CAT5/whatever cable, but the pinouts and signalling are quite, quite different.