What is needed (in general terms, as I'm not referring to a specific product) to have certain administrative software products page an administrator under certain scenarios, such as failure of a hardware component? I've read about this functionality being possible in several scenarios, but am unsure of what is needed for it.
Similar to the concept of paging an administrator is sending a text message, which I'm also not sure about.
What is needed from a software, hardware, OS, etc perspective to get such functionality in your system?