There are three options for the ring strategy:
This will ring available queue members one at a time based on the order they appear in the queue and go through that sequence until the call is answered.
This will ring the available queue member that has been offered a call least recently until they answer that call. If another call comes in, it will go to the next available queue member that has been offered a call next least recently
This will ring all available queue members at the same time until the call is answered.