Next generation packet routers

Current IP/ATM routers use an electrical switching fabric/backplane and either optical or electrical interconnects between the line cards to route data. An electrical backplane and associated connectors limit the number of high speed interconnections due to practical considerations. Scaling these so-called third generation routers to the terabit regime with high port densities faces enormous problems due to the high interconnect and electrical power density. Packet routers with an optical switching fabric are considered as the next generation of IP/ATM Multi-Service routers which enable scalability towards the Terabit and Petabit regime. In this paper, various architectures with electrically active or passive optical switch fabrics will be highlighted and differences in terms of switching speed and scalability will be discussed. Recent results using a passive Array Waveguide Grating (AWG) router and fast wavelength tunable laser are presented in the second half of this paper.