Can I use SIPcity Cloud PBX if my on-premise PBX fails?
Yes, absolutely
Location: SIPCity > Select number > Inbound Calls.
Summary: Setting up a second layer of redundancy on your PBX.
Detail: Leverage our hosted cloud PBX voice service to provide your PBX with a second layer of redundancy, regardless of whether you are connecting via Peering or Registration.
Registration: Enable Call Forwarding to redirect to your specified alternate number(s) if the call isn’t answered within a designated time.
SIP Peering: If you don’t have a secondary IP/PBX, you can also enable Call Forwarding to redirect calls to alternate numbers. When our Active Polling service detects that your circuit has been off-line for more than 10 seconds, inbound calls will failover through to the alternates specified in your Call Forward.