| [hono-dev] Command and Control in Custom Protocol Adapter for indirectly connected devices |
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Hi Hono Devs,
We have recently started to use the new command and control feature of Hono.
Based on the HTTP Adapter provided by Hono we have a custom protocol adapter in place to support the integration of LoRaWAN providers.
The interaction model currently looks as follows:
+--------+ Lora +---------------+ HTTP 1.1 POST /loraData +---------------------+
| Device +---------> | Lora Provider +-----------------------------> | Custom Hono Adapter |
+--------+ +---------------+ +---------------------+
In Body: - Device ID
- Actual Payload
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For the authentication of the provider we make use of the Hono "gateway device"-feature.
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To send commands to a LoRa device, one has to send a message via HTTP POST to the LoRa provider, which takes care of the further handling of the command (queuing, etc.).
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The HTTP api of the LoRa provider can be invoked independently from previous interactions (It does not have to be the same instance of the adapter; Device doesn’t have to send telemetry first).
My question now: Could you please give as a hint how we could implement C&C of Hono in such a scenario?
Does our custom adapter have to create an AMQP link for command messages for each possible device and keep it permanently (hono-ttd = -1) open?
For such a scenario maybe a single generic AMQP link for gateway devices to distribute it to the concrete devices behind the gateway would be nicer.
Thanks
Chris |