How to choose between HTTP or MQTT?

[LuisSchweigard]

Hey guys,

I have a tiny question regarding TTN integrations.
I am currently working on my Bachelor’s Thesis and trying to connect TheThingsNetwork to my IoT Application. I understand, that there is always the option to use the TTN MQTT Broker, but now I found the TTN HTTP Integration.

My question is: what are reasons to use the former or the latter option? I have managed to get both variants working (HTTP with a Azure Function and MQTT with Telegraf) but I can’t quite tell which one is better.

[arjanvanb (Arjan)]

@LuisSchweigard

my Bachelor’s Thesis and trying to connect TheThingsNetwork

Totally unrelated to your question, but please write “The Things Network” with spaces in your thesis.

And part of the answer:

@arjanvanb

For one’s own server (like a Raspberry Pi), those are indeed the two options. As you don’t seem to understand the difference:

• An HTTP web server along with the HTTP Integration needs you to carefully open up your Pi to the internet (some settings in your modem/router) to allow TTN to connect to it, and needs you to set up the integration in TTN Console.

• An MQTT client for the MQTT Data API connects to TTN itself, so does not need the Pi to be accessible over the internet. Also, many Pi’s come with Node-RED installed, which has built-in support for MQTT. This does not need any configuration in TTN Console (though you could add an extra application Access Key for this specific client).

Both options need to be running at all times. (Though HTTP could be using AWS Lambda’s/Azure Functions and the like for on-demand access.)

[LuisSchweigard]

Thanks for your anwser and telling me about the proper spelling !

[arjanvanb (Arjan)]

Also, I think that the HTTP Integration uses MQTT under the hood, but I don’t know for sure. If it does, then HTTP adds another dependency. (Say: if the HTTP Integration does not work, then maybe MQTT still works fine, but not the other way around.) Would be great to know for sure, but things may change in V3.

And:

@mfalkvidd

A mqtt connection is persistent. For a https request, there must first be the three-way TCP handshake, then the TLS handshake, before the request can be sent.

Since mqtt performs the tcp and tls handshakes once (when establishing the connection), the connection is available for sending data immediately when data comes in from the device.

Cloudflare has a good description:

https://www.cloudflare.com/learning/ssl/what-happens-in-a-tls-handshake/

[descartes (Nick McCloud)]

@arjanvanb

Also, I think that the HTTP Integration uses MQTT under the hood, but I don’t know for sure. If it does, then HTTP adds another dependency

Hmmm, interesting, it would be good to find this out as there is no point stressing the system with MQTT, HTTP & DaTa STorage if HTTP is going to go off line if MQTT goes off line.

PS, I capitalised the T’s for all three protocols, seems only fair.