Block diagram as text software?

[networkloser]

There are various stuffs for UML like plantUML etc. But what about for network block diagram. Are there anything?
I want to make diagram as code.


For example something like this:

A->B->C

Where A, B and C will be blocks. Request-response cycle will be shown.

[icecream-guy]

I'd say Visio, but expensive

[deanwebb]

For a free version of Powerpoint, which has shape art in it, there's LibreOffice suite.