Hi Godot,
Glad we're making progress here!
Please keep in mind that SP1 and SP2 do not refer to the Phone Ports of your OBI202, per se. On your OBI202, you should actually be seeing SP1, SP2, SP3, and SP4. Yes? To double-check, take a look under -> Voice Services and -> Physical Interfaces in your OBI Menu.
If I understand correctly, SP1 and SP2 would be linked to Phone Port 1 by default, and SP3 and SP4 would be linked to Phone Port 2. This feature by Obihai allows you to use two voice service providers on each physical phone port.
I don't know enough about the OBI202 to pinpoint the reason for the partially-successful calls on the other port. Perhaps it was a failover feature as you suggested. However, if you have 2 (two)
Voip.ms DIDs associated with only 1 (one)
Voip.ms account, then I would suspect that you may need to double-check your
Voip.ms settings. Perhaps if you could log in to your online
Voip.ms account, you may see some options for how the call routing/priority is handled for your two DIDs. With some VOIP providers, an additional sub-account is provided in order to distinguish between the two DIDs. Or, your two DIDs may be set to both forward to the same, single
Voip.ms account you currently use.
Perhaps someone else with
Voip.ms and/or OBI202 experience can comment on this!
Keep us posted!
pc44