Reliable Multicast has been applied to large-scale contents delivery systems for distributing digital contents to a large number of users without data loss. Reliable contents distribution is indispensable for software updates and management data sharing in actual delivery services. This paper evaluates the implementation and performance of RMTP; a reliable multicast protocol for bulk-data transfer, through the developments of contents delivery systems. Software configuration is also examined including operation functions such as delivery scheduling. Furthermore, applicability of reliable multicast to emerging broadband networks is also discussed based on the experimentation results. Through the deployment of the protocol and the software, performance estimation has played a key role for constructing the delivery systems as well as for designing the communication protocol.

At present, a demand to the technology of contents distribution by which each user can request the desired content through network is increasing. There are some merits and demerits respectively with the existing on-demand systems for contents distribution, such as the methods based on broadcast and select transfer or multicast one. In this paper, we propose a hybrid scheduling method which adaptively uses both broadcasting and multicasting in order to improve the system efficiency. Adequate channel boundary to adopt two different transfer mechanisms is found through analytical consideration. Also, performance improvement of our proposal is verified in terms of response time and request blocking rate through computer simulation.