The cause of this for SMS is not the phone, but the network, and the underlying technology. SMS is push-based, compared to Internet messaging which is pull-based, and uses a backoff-based redelivery mechanism. Once your message is sent and has been received by your carrier, deliver is attempted, but if the recipient handset is unavailable the carrier will try periodically to redeliver, and if it still fails the wait period between delivery attempts will increase the longer the recipient is unavailable. May be every five minutes for the first hour, but then once an hour for the next 24, for example.
Each message is its own distinct entity which is treated separately for delivery, just like letters in the post. That’s why it was possible to get this sort of odd-seeming scenario where you have a newer message that made it through, while an older one is still stuck in retry somewhere.
The issue most likely seemed to me to be just that plus the fact that the google service would never retry on SMS when switched back to SMS. So your message wouldn’t be sent until the recipient had a WiFi connection. Ridiculous implementation.
Kinda interesting to hear about this stuff as someone who grew up when everyone was already on WhatsApp (at least here in Germany)
The cause of this for SMS is not the phone, but the network, and the underlying technology. SMS is push-based, compared to Internet messaging which is pull-based, and uses a backoff-based redelivery mechanism. Once your message is sent and has been received by your carrier, deliver is attempted, but if the recipient handset is unavailable the carrier will try periodically to redeliver, and if it still fails the wait period between delivery attempts will increase the longer the recipient is unavailable. May be every five minutes for the first hour, but then once an hour for the next 24, for example.
Each message is its own distinct entity which is treated separately for delivery, just like letters in the post. That’s why it was possible to get this sort of odd-seeming scenario where you have a newer message that made it through, while an older one is still stuck in retry somewhere.
Makes sense. I think it’s similar to how email works, right?
Email has bits of both in the chain.
Using the olden-days of desktop email apps as an example then:
The issue most likely seemed to me to be just that plus the fact that the google service would never retry on SMS when switched back to SMS. So your message wouldn’t be sent until the recipient had a WiFi connection. Ridiculous implementation.