Originally Posted by
canopus27
When Air Canada send you the "boarding has now started" text message ... I'm reasonably confident that Air Canada are not connecting directly to a carrier, but are using an aggregator like
Twilio. They send it over the internet, and you receive it as a text message.
Do you count that as SMS?
Guaranteed they use something like Twilio. Twilio is what the apps I am responsible for use, and what anyone who needs to do e.g. email, SMS, etc. at scale from an application uses.
From the perspective of Air Canada it is not an SMS. From Air Canada's perspective it is an API call (JSON over HTTPS) and from my end it ends up as an SMS message. Depending on how AC has their Twilio (or whatever) account set up when I respond to that SMS it ends up back as an API call on the AC end. So from AC's perspective they're making an API call over HTTPS and getting a response back via a Webhook. If AC decided to host this application from a laptop running on WiFi on a 787 it is going to work because it is all running over IP and from their end is not SMS.
To bring it back to the point, people in the air using ACs system cannot send/receive SMS, because SMS by definition uses the cellular network. They can use other over-IP protocols to send and receive messages.