An Architecture for a Scalable Video-on-Demand Server Network with Quality-of-Service Guarantees

In this paper, we describe an architecture for a scalable distributed server management system which is capable of managing media assets stored on large-scale media server networks. In addition to the functionality for a decentralized management of the whole server network, the server management system allows to make bandwidth reservations even in advance for streaming in real-time and transmitting media assets. This increases the QoS for end-users since bandwidth reservations for streaming applications can be planned and established a long time before the actual streaming process takes place. Moreover, this approach allows a tight estimation of the duration required for copying media assets among different servers of the network. In order to minimize the required amount of network bandwidth for copying media assets and to reduce the total number of copying processes, the management software provides the functionality to place media assets on the servers of the network in a way that assets of particular interest for a certain client are located on the client's local server. In this paper, the architecture of the server management system itself is presented together with the approach used to provide QoS guarantees for end-users. The overall system is using the differentiated service model. Besides the technical concept we also present results of the integration of the system into the corporate network of a german company.