Hi all,In our application we Use VoIP Type push notifications to give a heads-up for the mobile phone.This allows the mobile phone to:1) If the application is killed, start it in background2) If the application is in Background, start running the application statemachine3) If the Phone is in deep sleep, Wake up and start the application in BackgroundDue to the above, our application arrives in a state where we can receive an incoming voip Call.It has been observed that there is a delay in the push notification arrival at the mobile phone.Delayed arrival/delivery of Push notification has been measured of about 6 sec or sometimes never arrives.This espicially is the case when we have an iPhone without sim-card.Note :- This was tested on a controlled setup with large number of iterations with good WiFi and internet connectiviy)- We ensured during testing that the push was actually dispatched to APNS.It is unknown as to what exactly causes a variation in the arrival of the voip notification.Can someone explain why :- Voip messages arrive late depite they should be 'instant' ?- What could explain the difference in measurments with/without sim card ?Best regards.