Understanding PUSH notification limitations

[GrandWizard]

As with all "app" providers, we rely on Apple's APNS and Google's FCM push-notification services to deliver alerts to your phone. The Envisalerts servers do not communicate directly with the app.

Both Apple and Google offer this service for free but it is with restrictions. Firstly, it is a "best efforts" service and there are no guarantees at all for delivery. As well, both services reserve the right to limit or "collapse" what they deem are duplicate notifications into a single notification. Finally, the phone itself may not notify you of a new notification if you have too many unacknowledged notifications already.

What this means is that your PUSH alerts are cannot be guaranteed to be delivered, but in normal use they generally all are.

If you find you are missing PUSH notifications, the most common culprit is that your message has been "collapsed". This means that Google has seen multiple notifications from the same server to the same phone in a certain period of time and will no longer deliver any more as it deems them as duplicates even though they are not. This is the most common problem we see when people are testing as they are generating a lot of events in a short period of time. Be patient and be aware when used normally for events that might happen only a few times a day, the PUSH notifications do not get collapsed.

The other major culprit is that your delivery queue has too many unacknowledged notifications and new ones are either dropped or put on hold. This seems to be phone specific and differs between manufacturers.

If you intend to rely on PUSH notifications for alarms you need to be aware of these limitations and you should consider one of the other notification methods which do not suffer from these issues. And as always, self monitoring is not a replacement for professional monitoring. When you factor in your insurance discount, professional monitoring may actually cost you nothing per month.