Abstract
Multicast routing protocols have been built and deployed, basically, using two types of trees: single-source, shortest-path trees and shared, core-based trees. Core-based multicast trees are more scalable, but they generally have higher average delay and traffic concentration. In this research, a hybrid multicast structure Of single-source, shortest-path trees and shared trees with multiple cores is investigated The hybrid design provides lower average delay for many-to-many multicasting. Simulation results indicate that the average delay using Hybrid Multicast Tree with multiple cores (HMT) converges towards the average delay using the shortest path free, without a considerable effect on bandwidth cost, at the price of increased number of multicast states.