Hi, Thanks for replying. I filed a bug FB17104567. And regarding the question you asked. It is not necessary to open the app. Just reconnecting to internet is enough. The voip push is delivered immediately after internet is available. No need to unlock iPhone or open the app.

To rule out dependency of server connection, the issue can be reproduced with below steps also. Put our voip app in background and put iPhone in airplane mode. Now if a caller makes call to this app, the call should be delivered through voip push. But push is not delivered because of airplane mode. Wait for few minutes and then disable airplane mode. As soon as airplane mode is disabled, we receive the voip push and phone starts ringing. But call has already been ended due to timeout, so this is just a ghost call. We had set a low value for 'apns-expiration' and so expect that the push should not be received after disabling airplane mode after waiting for few minutes.

Thanks for replying. I understand that sometimes push notification can be delivered with a delay due to network conditions. But in our case it is happening consistently. Steps to reproduce are as below. Put our voip app in background and lock iPhone. As app is put in background, socket connections gets disconnected from server. Now if a caller makes call to this app, the call should be delivered through voip push. Voip push should ideally be received even if app is in background and iPhone is locked. It is connected to a good wifi network. But it does not receive the voip push. User unlocks iPhone and opens voip app. As soon as user opens app, the voip push is received and phone starts ringing.