A new fair bandwidth allocation algorithm for multimedia multicasting in DiffServ

Multicast is a bandwidth efficient mechanism for delivering the same data to multiple receivers simultaneously. Layered multicast, which is suited for high-bandwidth multimedia traffic like video, may be used to differentiate between receivers of the same multimedia content based on their processing and bandwidth resources. To achieve fair bandwidth allocation in layered multicast, max-min fair allocation solutions have been proposed. However, existing solutions either use non-scalable centralized computation or require core routers to maintain per-session information. Maintaining per-session information in core routers violates the core stateless principle of DiffServ architecture, which is proposed as a scalable QoS solution in the Internet. In this paper, we propose a new scalable distributed max-min fair bandwidth allocation algorithm for DiffServ, which runs iteratively and does not maintain per-session information in core routers. The new algorithm is proved capable of achieving max-min fair bandwidth allocation. Through analysis, we show that the new algorithm complies with core stateless DiffiServ architecture to have O(1) storage complexity in core routers