Despite the availability of video-on-demand (VoD) services in a number of cities around the world, the large-scale deployment of VoD services has not been widely explored due to economic constraints. The high complexity founded in these systems makes the design process very difficult.

This study presents a VoD system design for a highspeed metropolitan network, based on ATM technology, located in Brazil. To accomplish this goal, we have utilized our own simulation-based tool for VoD design called VODSim. This tool allows VoD research on any VoD platform, simulating the complete flow path followed by requests from clients to servers passing through the network infrastructure, allowing the configuration and tuning of multiple system parameters. Using VODSim, we analyse possible VoD architectures for the proposal environment (i.e. Centralized-server, Independent-servers, One-level-proxies and Distributedservers), studying key-parameters that have influence in system design.

Experimental results show that Distributed-server architecture is the one that adjusts better to the analyzed infrastructure, improving streaming capacity by 16%, 25% and 28% more than One-level-proxies, Centralized and Independent-servers respectively. Taking in account future growth in VoD system, the Distributed-server even provides an unlimited scalability through new local network incorporation and using P2P techniques.