Connecting multiple phone calls visa VOIP using c# : I am trying to achieve below 
Me (customer) press a button to speak to agent (from mobile app - Xamarin)

    Then login tries to connect to (gets top 5 agents list from database / JSON  - top 5 agents will vary every time based on time)
    
    Agent 1 - rings agent 1 mobile phone as normal call, if No answer after 25 seconds  
    Agent 2 - ring for 25 secs 
    Agent 3 - ring, connected

Once call finished log date time of call

I am happy to use any VOIP provider or any other solutions.
