ALLEGRO PCB ROUTER L, XL The Cadence Allegro PCB Router routing environment is the leading solution for automatic and interactive interconnect routing for printed circuit boards (PCBs). Designed to handle routing challenges from simple designs to high-density PCBs requiring complex, high-speed design rules, it uses powerful shape-based algorithms to make the most efficient use of the routing area. The results are increased completion rates, higher productivity, and shortened design cycle times.