Random Early Detection Assisted Layered Multicast

The deployment of the Random Early Detection (RED) al- gorithm in multicast routers can improve the performance of layered multicast congestion control schemes. In this paper, a new layered multicast protocol called RED Assisted Layered Multicast (RALM) is proposed to realise the integration of RED and layered multicast. It utilises the packet marking feature and two-level drop prioritisation capability in the Differentiated Services (DiffServ) architecture to differentiate losses in the layers of an RALM session. By marking the layers' packets appropriately and dropping them differently during congestion, the RALM protocol guides all receivers to a stable optimal subscription level that satisfies their common bandwidth requirement within a short period of time. Moreover, the DiffServ architecture permits the network administrator to control the amount of bandwidth consumed by RALM sessions through the deployment of suitable queue schedulers in the routers