Calix has developed a line card and chassis architecture that can include the DLC and DSLAM functions needed in most local-loop PSTN networks. It also provides optical add/drop multiplexing for on-board SONET and Gigabit Ethernet services with optical interfaces to fiber networks. Embedded edge switching and digital-cross connect functions work together to process, groom, and manage any combination of TDM, cell, and packet traffic, including ATM, frame relay, and (IP/MPLS).