Applies to VoipNow 4.0.0!
SIP forking is available starting with VoipNow 4.0.0. SIP forking refers to the process of calling multiple devices registered to the same extension.
VoipNow has implemented parallel forking. When a call is placed to an extension with multiple registered devices, all devices will ring at the same time, allowing the user to pick the call from any of them. There is no need for an incoming call rule to make all the devices ring at the same time.
Here is a typical flow for a call received by a VoipNow server that will fork the call to, let's say, 2 devices at a time.
Both devices will generate 180 Ringing. Whichever device answered the call will generate a 200 OK that will trigger a CANCEL request for the other called device.
When multiple devices are registered on the same extension, the Extension Overview section displays all the devices, including the IP address and expire type for each of them.
All functionalities like presence or MWI notify will be sent to all devices at the same time on the condition that all devices are subscribed for presence or MWI notifications.
There is a limit to how many devices are registered on a single extension. The default limit in VoipNow is 20 devices.
As long as one of the devices is involved in a call, the other(s) will be able to make outgoing calls, but only if the concurrent call limit set on the user allows multiple concurrent calls.
To transfer a call from a device to another, you can use the call parking feature, which will park the call from the active device and unpark it on the device where you like to continue the conversation.