Half Overlay Multicast Routing for Hybrid Networks
面向混合网络的半覆盖组播路由协议

Although multicast can be implemented in every layer of network,the existing multicast protocols rarely meet the demands both for flexibility and efficiency at one time. In general,hardware multicast and IP multicast are more efficient than overlay multicast,but the situation of flexibility is quite the contrary. This problem is much pressing in hybrid networks,in which the two demands have the same priority. This paper proposes a novel protocol named half overlay multicast routing that integrates IP layer in-group regional broadcast,address-and-port-translation based overlay multicast and extensible support for hardware multicast into one single model,where the three mechanisms are chosen dynamically for data delivery. By this approach,HOMR obtains the flexibility of overlay multicast. The simulation results show that the overhead of HOMR is low and the performance of HOMR is comparable with pure IP multicasting.