A rate-based multicast protocol for large-scale reliable transport

This paper presents a RAte-based Multicast Protocol for lArge-scale Reliable Transport (RAMPART), which is designed to provide scalable, TCP-friendly and responsive reliable multicast transport service for applications of bulk-data transfer. We proposed a dual-bitmap mechanism to solve the problem of duplicate packets and eliminate unnecessary retransmissions. A new scalable indirect RTT measurement algorithm is introduced. And Specific Receiver selection process is distributed among all group members with records of Local_SR_rate and Global_SR_rate assuring correct SR selection and avoiding frequent SR changes. Control tree is constructed with the aid of multicast routers using a label-based sorting algorithm. RAMPART protocol was implemented on NS. Simulations were conducted with respect to RTT measurement, throughput analysis and TCP-friendliness. The results show RAMPART is effective.