I need to know if its possible to make push notifications without use the APNS.
And if it can be done, what are the best options?
Web server ->pushNotification-> Device
What about the VoIP apps? --> Can we push notification without using APNs?
Thanks.
No, there is no way to use Push notification without APNS. This is restriction from Apple and is documented here
No you can not push notification to a device without using Apple's push notification service.
It is not possible to display push notifications for your application in the same way that the built in push notifications appear without using the Apple Push Notification Service.
You may be able to set up some kind of web socket-based solution, but that will not work when your app is in the background, thus defeating the point.
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来源：https://stackoverflow.com/questions/10598780/is-there-possible-make-push-notification-without-apns