Patent ID: 7170895

Claim:
A modular switch comprising: a plurality of primary switch interfaces, each primary switch-interface coupled to a first set of N>0 primary local links; a plurality of secondary switch interfaces, each secondary switch-interface coupled to a second set of N secondary local links, said secondary switch interfaces and said primary switch interfaces forming a plurality of switch-interface modules each said switch-interface module comprising one of said primary switch interfaces and one of said secondary switch interfaces; and a passthrough interface having N internal links interconnecting said one of said primary interfaces and said one of said secondary switch interfaces; wherein each of said N primary local links of each said primary switch interface connects to a secondary switch interface of a switch-interface module from among a first set of N switch-interface modules and each of said N secondary local links of each said secondary switch interface connects to a primary switch interface of a switch-interface module from among a second set of N switch-interface modules wherein each said switch-interface module is common to N arrays of switch-interface modules and the switch-interface modules within each of said N arrays form a ring.