We are trying to use push notification in opensips. We used new module which provide push notification, but I think there should be other way to wake up the linphone app, LOGIC: some way linphone app will send push device token to opensips... opensips will fetch device token and store it on database for future use, when app will try to call to linphone app opensips will check that any device token is exist in database with that particular extension and if present opensips will send voip push token to iOS app to wakeup and app will send re register.