Simultaneous Call is slightly different from a normal call, instead of being forwarded to one person at a time, several phones can ring at once.
Using the Dial applet from your Flow Creator, smrtPhone gives you the option to call a group of people simultaneously or sequentially. This option can be found under the name of “Simultaneous Call”.

Then you will have the choice to set Simultaneous Call to yes/no.
If you choose to enable this option, all the members within the group that you previously assigned in the “Dial Whom” box will be called at the same time ( the system will call both the dialers within the browsers and their personal devices at the same time if they have an active personal device in their account)

You can set your incoming calls to simultaneously ring your work and your personal number or contact in case you are busy or momentarily unavailable.
You also have the option to call multiple phone numbers at the same time by adding the phone numbers in the “Dial Phone Number” box
(each number must be placed on a new line)

If you choose to disable the Simultaneous Call option, the system will still call all the phones within the browser at the same time for every member of the group but as soon as the call is marked as missed it will be forwarded to each member’s personal device sequentially according to the order of the member in the group.
Note: Simultaneous call does not work with VoIP based calls.
The same principle applies to the numbers added in the “Dial Phone Number” box. The system will call each number sequentially according to the order of the number in the box.
This setting can help ensure that callers do not get the busy signal and their calls do not get missed.
Note: We recommend that you check the entire article from the documentation section.