Android SMS Gateway Using MQTT | Hacker News Reader

Android SMS Gateway Using MQTT

github.com

47 pointsmodinfo11 comments

I did something like this 10 years ago. I had a 3G modem with a SIM card and it allowed more than the regular SMS app on your phone. Obviously I didn't have a whole app, just a simple CLI.

For example, you could send class 0 SMS (flash) with it. The kind of SMS that shows up on your screen, and all you can do is click OK, and it just disappears.

https://stackoverflow.com/questions/5557135/sending-fullscre...

Would this still be possible now? Especially sending class 0 SMS?

Or has something fundamentally changed so makes no sense to bother trying

It is definitely still possible to receive class 0 sms, because I believe that is what you are getting in the US when you get an amber alert or other emergency warning. As far as I can tell, all US carriers restrict the sending of these to just themselves (or official gov sent through them). Otherwise you can imagine the abuse potential.

Is there something like this but for calls?

Make your phone into an SIP/VoIP server? So that you can receive and make calls from any/many Internet clients while the Android phone with SIM is plugged in at home.

This would only be possible on rooted devices, and even then it could take some considerable effort depending on the manufacturer. The way call audio is routed on Android is SoC specific and often a pain to intercept or alter.

Maybe you could use something like Ubuntu Touch and utilize pipewire for the audio routing? Edit: I guess you should be able to use a script to route the call audio through to a Voip client running on Ubuntu and vice versa.

Like this software? Not that I've seen, but there devices that offer that functionality.

VoIP GSM gateways, sometimes with basic PBX functions, are absolutely a thing. Yealink do some (that I've not used) that act as a SIP registrar, you can basically log SIP clients straight into it.

And there are more heavy duty options that take 16+ SIM cards that are basically a rack-mountable mobile call centre.

I did something similar 20 years ago. Setup 4 Nokia phones with 4 SIM cards for the 4 different networks in Germany.

It was possible to connect them via a serial cable to a linux machine and receive/send SMS.

Used that to offer a horse betting service: people could bet on horses via complex SMS syntax. It worked, but never made enough money :)

A popular alternative, also selfhosted: https://github.com/vernu/textbee

This seems cool and all, but wouldn't it likely violate ToS of your carrier by doing something like this -- especially if it gets to be of any appreciable scale?

Obviously it depends on what you do with it and the terms of your provider and local regulation. Spamming is forbidden if done manually too, you know? So is probably abusing "unlimited" plans with high throughput if you read the fine-print of your contract.

For a personal SMS gateway so you can have mobile network access without having your personal location tracked, it should be fine.

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