So if the length time for the servicing of a subsystem is kept short, failure should become remote. On the other hand, if the time interval is too long the subsystem will fail. Both strategies clearly carry a heavy price as both are suboptimal. Being rational, companies employ preventive maintenance when the cost of a failed subsystem exceeds the cost of preventive maintenance. This is why power utilities, when they have not been sabotaged by Greenies, practise preventive maintenance, regardless of Fist's claims to the contrary.
Telephone companies are no different.
They will undertake whatever measures are necessary to maintain their systems up to the point where the cost of the additional maintenance exceeds the cost of failure. Alternative strategies are costly and wasteful. Ultimately, it is the consumer that foots the bill, not the company. Consumers will always get what they are prepared to pay for. This reasoning will, however, have little effect on anti-market zealots like Fist who prefer the cosy ideology of interventionism to any serious study of economic thought.