What are the ways to ping ESP devices of an IoT network besides the LWT mechanism of MQTT?

Question

Computer networks

The LWT of the MQTT protocol proved to be unreliable in working with ESP devices, it became necessary to come up with another solution. A web socket solution came to mind with Centrifugo, with monitoring of join/leave events in a channel with connected devices. What other solutions could there be?

PS The device does not have an IP address, it will not be possible to ping it from the outside

Thank you.

Answer 1

Websocket is just the best if communication is done through web technologies.

Answer 2

TutorialWP!!!!
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Answer 3

Only google

Answer 4

You make a theme (skin, template) for wordpress and then manually transfer the content.

Answer 5

For the future: PHP stands for PHP Hypertext Processor