Video-on-Demand (VoD) is one of the most important services that should be provided by future networks. Some characteristics of the Internet, however, make it difficult to provide VoD services with Quality of Service (QoS) assurance. The China?s high performance broadband information network, named 3Tnet, is a new network architecture designed to provide large-scale video services. Based on the 3Tnet, we propose a novel architecture for Video-on-Demand services which could ensure QoS. A new scheduling policy based on request time has been used to improve system performance. Simulation results show that the proposed architecture for VoD services on the 3Tnet is ideal in terms of service latency, throughput and renege rate.