The Evolution of Switch Intelligence: An AT & T Network Perspective

摘要

Since the mid-1970s, the 4ESS™ switch has been the principal switching system—first in the AT & T Long Lines network, and today in the AT & T network as a whole. Until now, its main call-processing engine has been the 1A processor. The 1A is an ultra-reliable central controller designed to support high-volume electronic switching of simple phone calls having few if any special service features, like those in AT & T 800 service. In recent years, however, rising call volumes and sophisticated new longdistance service features have created the need for much more processing capacity and "intelligence" in the 4ESS switch. To meet this need, the AT & T Network Services Division—which manages the AT & T network-chose AT & T Network Systems Group''s 1B processor to replace the 1A processor in 135 4ESS switches. The 1B processor more than doubles the call-handling capacity of the 4ESS switch while performing at least as reliably as the 1A processor. Not only that—the 1B processor can connect to a community of other processors, databases, and switch fabrics.