When Fongo for iOS loses connectivity to Fongo back-end services, we rely on Apple's remote push notification service to find you for an incoming call. You can distinguish a remote notification from a local notification by the phone number having a + (plus) sign at the beginning of the number in the notification itself, a + (plus) means it is a remote notification. Missed calls from remote notifications will only be added to your call History if you actually press the notification. If you unlock your phone to dismiss your lockscreen notifications, or you ignore a remote notification while the phone is unlocked, these missed calls will not appear in your call history.