Prevention Prevention is the best way to avoid a network problem. The STP pairs are not colocated, but are usually hundreds of miles away from each other, and operate at just under 50 percent capacity. With this architecture, if something happens to one STP, its mate can pick up the full load and operate until repair or replacement of the damaged STP can be made. Guiding the overall work of the DIF are two controllers running simultaneously, so that if one experiences a problem, the back-up controller can take over without a customer noticing. This feature will send a customer's traffic to another Digital Interface Frame at another 4ESS location if the customer's primary switch encounters a problem.
Power systems provide direct current from redundant rectifiers fed by commercial power.
If commercial power fails, batteries, which are kept charged by the rectifiers, provide backup power. An additional stage of redundancy is provided by generators, which can replace commercial power. Network Diversity Diversity is a concept of providing as many alternatives as possible to ensure survival of communications when some kind of natural or man-made disaster strikes. Cables have different types of sheathing designed to protect against a variety of conditions from rodents, to lightning, to shark bites. Should any particular circle be cut, such as by a backhoe operator hitting a fiber cable, a fair amount of traffic can be sent over one or more adjacent circles.