Packet Flow between Smartthings hub , Alexa and connected devices

I am curious about the data flow between devices.For example, if I give Alexa a command to execute a Smarthings scene how do the commands reach the end devices. Does Alexa send the packets to the hub that tell the hub to issue a series of commands to the devices , does the hub redirect the packets to the end-user devices or does ALexa send packets directly to the end devices based on rules given it by the hub?

Generally:

Alexa > Alexa skill for SmartThings > SmartThings Cloud > SmartThings Location > Hub > Device

And device info to Alexa is basically the reverse…

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As @nathancu Described, the echo does not have any direct communication with the Devices on your SmartThings account. Echo talks to its cloud, its cloud talks to the smartthings cloud, the smartthings cloud talks to the smartthings hub, the hub sends the command to the end device.

This is true for pretty much any Alexa command with any home automation system.

The exception is Zigbee devices which are connected directly to an echo plus Or echo show. In that case the echo device is acting as the hub for that network and the messages are sent directly. But then those devices will not appear in smartthings since they can only belong to one Zigbee hub.

https://www.amazon.com/gp/help/customer/display.html?nodeId=GCC6XV9DX58VW5YW

I have a few devices set up this way at my own house to make sure that I have some local voice control of a few lights even if the Internet is out. :sunglasses:

Note also that this is not a simple packet delivery system. The protocol for the messages between Echo and its cloud are not the same as the protocol for the messages between the smartthings cloud and its hub. In fact, the protocol for the messages between the smartthings cloud and hub is not the same as the protocol for the messages between the hub and the end devices. So requests are being sent and fulfilled, but the actual content of the message on each leg may be different.

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Thanks that helps

That is quite a path. It explains by things can be inconsistent. Thanks

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I believe that the Smartthings cloud resides in AWS. But a command still could travel 1000 miles to go from your kitchen to your !Icing room.

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True, but this is true for almost all voice processing at present because it just requires a great deal of computing power to do natural language recognition. That’s not likely to reside locally. For example, everything on apple’s HomeKit home automation platform runs locally, except voice processing.

There’s one exception. As I mentioned, there is a very limited amount of voice processing for Zigbee devices which are connected directly to an echo plus or echo show.

There are persistent rumors that everyone from Apple to Google are working on local voice processing, but it’s not available yet.

If you set aside voice processing, smartthings remains a largely cloud-based system. There’s very little that can run locally.

If running locally is important to you, then there are some alternative home automation systems which do run locally (except for voice processing and other third-party integrations), at least after initial set up, including Homeseer, Hubitat, home assistant, Vera, and Apple’s HomeKit. But it’s just not how smartthings was designed.

At this point I am gathering information.I was a network engineer so I like to know how things flow. I really appreciate your thoughts. It helps me understand how all of this is glued together

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I was a network engineer as well! :sunglasses: