Cisco Systems extends WAN connectivity by adding high-speed ATM access to remote branch offices with the Cisco 2691, 3600, and 3700 series ATM OC-3 network modules.These network modules support STS-3c and STM-1 framing standards over multimode, single-mode intermediate-reach, and single-mode long-reach fiber optic interfaces. All versions consist of a single-port network module with SC type connectors. The single-mode ATM network modules provide high-speed trunking for users with access to fiber WAN, while multimode is ideal for connecting high-speed servers, switches, or hubs equipped with and OC-3/STM-1 fiber connections.