IoT Planning Software?

My Company’s designing a new IoT system. To date, we’ve just used a whiteboard to visually represent the system, being network, devices and the power/data layers interconnections & flow.

Is there any off-the-shelf (ideally free) IoT-system-friendly planning software?

For reference, a result looking like the attachment would be fine - graphics are intuitive & simple.

I use Open Office Draw for things like that - but I am sure there are programs that do the outline part better

Here's OP's pic.

How to inline an image

Have a look at drawio: I'm sure it will have graphic elements like that.

Lots of free. CAD software.

You can zoom in and put phone numbers or extensions on desks
Network node addressrs

Here's OP's pic.

Well, there you go, it looks like he has planned it already.

Well, there you go, it looks like he has planned it already.

It was tough, but now it is time for promotions and bonuses for the IoT team!

Thanks for the replies.

We've gone with DrawIO, importing icons from a few different icon sites. DrawIO had pretty much no learning curve, made it easy to add text/notes & the arrows linking items were dynamic when the objects were dragged around... I can recommend.

That other pic was just a reference... Ours ended up looking readable enough, see below: