Active error recovery for reliable multicast

An error recovery scheme is essential for large-scale reliable multicast. We design, implement, and evaluate an improved active error recovery scheme for reliable multicast (AERM). The AERM uses soft-state storage to facilitate fast error recovery. It has the following features: a simple NAK suppression and aggregation mechanism, an efficient hierarchical RTT measurement mechanism, an effective local recovery and scoped retransmission mechanism, and a periodical ACK mechanism. We implement the AERM and study its characteristics in NS2. We also compare performance with ARM and AER/NCA, both of which are representative active reliable multicast protocols. The results indicate that AERM can achieve considerable performance improvement with limited support from routers. Our work also confirms that active networks can benefit some applications and become a promising network computing platform in the future