The Cisco 6400 series universal access concentrator (UAC) is a scalable service gateway that enables the selection and delivery of high-speed network services, virtual private networks (VPNs), voice- and entertainment-driven traffic delivered over any type of DSL service. The Cisco 6400 UAC combines the richness of Cisco IOS ATM switching and routing capabilities, and value added service selection in a modular, scalable, redundant, NEBS certified and ETSI form factor. The Cisco 6400 series UAC is an integral part of the Cisco end-to-end DSL architecture.