Are you the administrator of a network? Do you think part of your job description is to know the status of the network? If so, do you use network monitoring software? If not, why not?
It seems to me that if you don't monitor the network, you are being reactive and turning your customers into your monitors. It also means you're the last to know when something goes wrong.
Doing services this way is like a mechanic saying he or she will wait until the airplane crashes and they get a telephone call from the fire department before they'll check whether there is oil in the engines.
In my opinion, waiting to get a call from someone telling you the network has crashed and burned is not an intelligent way of doing business. Especially since the tools to monitor networks are available for free:
The point is there are tons of software out there to monitor network status. Take a look and find one that meets your needs, install it, and know what is going on.
Aloha!