I want to implement real-time push notification in my web application for voice calls. I have analysed WebSockets, Long-polling, Firebase and Atmosphere. Both Firebase and Atmosphere are not reliable, for Atmosphere, sometimes push does not reach to the browser and for Firebase, when token expires, onTokenRefresh method is not called because of which no notification is received on the browser side.
Is there any other solution available which can give web push notification like google hangout or Facebook or WhatsApp call?