Dear sir;
The UC500 BRI version comes with 2 BRI ports, we should be able to use it to connect either a device or line as the interface is NT/TE. If your UC500 is FXO, then you need to add a VIC2-2BRI-NT/TE (this is the Voice Interface Card with 2 BRI ports).
Please let me know if this answer your question. Not sure I understood it properly.
Regards
Alberto