IMPROVING ON THE BEST - LIKE A 1A, ONLY BETTER

Since 1976 the 4ESS(TM) switch and its 1A processor had been the work- horse of the network. As technology advanced and customers required ne w services, the capacity of the 4ESS switch came close to being exhaus ted, making it necessary to develop a successor to the 1A processor. D evelopers of the 1B processor were presented with the challenge of des igning and implementing a system that could accommodate the new networ k demands, that would be ''like a 1A, only better.'' This paper descri bes several problems encountered during that project and how they were solved.