Abstract: Offering vertical services to subscribers and service providers is an avenue to immediately improve the competitiveness of digital subscriber line access service, for example of the type offered by a local exchange carrier. To deliver high-quality vertical services, however, the underlying ADSL Data Network (ADN) or the like needs to establish Quality of Service (QoS) as a core characteristic and offer an efficient mechanism for insertion of the vertical services. The inventive network architecture introduces QoS into the ADN, in a manner that enables the delivery of sophisticated and demanding IP-based services to subscribers, does not affect existing Internet tiers of service, and is cost-effective in terms of initial costs, build-out, and ongoing operations.