Due to the ubiquitous nature of the Internet, it is being targeted to support video applications, such as Video-On-Demand (VOD). However, with the growing popularity of the Internet, congestion in the network poses a great hurdle in transferring real-time video data. For pre-compressed MPEG-2 video streams, the network may not be able to maintain acceptable level of Quality of Service (QoS) if there are insufficient resources available during the life of the connection. In such situations, we can use rate control to reduce the bit rate of the video according to the available resources. In this paper we propose a scaleable delivery mechanism for pre-compressed VBR MPEG-2 video streams, where the traffic rate is adapted according to the network congestion status. Using this scheme, a reasonable level of QoS is maintained when the network is congested. Based on the scheme a prototype system has been developed which demonstrates the usefulness of the scheme.