On the dashboard it always shows device offline. Doesn't matter if i use Zoiper or the B315 router's anologue phone.
Both devices can register and i can make calls, but not receive.
When I change the registration IP It does ring when i try to call it but only for a 1miute or 2 and then it stops.
maybe try zoiper, I think the issue is that asterisk sees your registration but the status is unreachable, this is why we can send the call to your device:
Status : UNREACHABLE
Useragent : CPE/VOIPER