问题
So I have VOIP calling application, where everything is working fine.One user can call to other user and can talk.
But I am facing the problem where I don't understand How Can I fix that Problem.
When user1 is calling to user2, user1 sending voip push request to user2. but user2 is offline or not connected with internet when push notification received, after that when user2 back online voip push delivered, as soon as voip push delivered I show the callkit interface but that time user1 has already disconnected call.
So How can I identify the voip push is expired push or not
What I have tried so far
---> I have connected socket and send message to other user (other user info received from payload ) after that I will wait for 5 seconds if I didn't get response from user1 then I am not showing callkit interface
---> I have tried apns-expiration to 0 but still push delivered
There must be a better way like whatsapp handling this
Please guide me
来源：https://stackoverflow.com/questions/57609832/handle-expired-voip-push