1995,
Calvert, Kenneth L.,
Zegura, Ellen W.,
Donahoo, Michael J.
Multicast routing is an important topic of both theoretical and practical
interest. Some recently-proposed multicast routing algorithms involve the
designation of one or more network nodes as the "center" of the routing
tree for each multicast group address. The choice of this designated router
(which we refer to as the "core") influences the shape of the multicast
routing tree, and thus influences performance of the routing scheme. In this
paper we investigate the relationship between the choice of core and three
performance measures. Specifically, we compare various methods of selecting
a core with respect to their effect on bandwidth, delay, and traffic
concentration. We conclude that simple methods are adequate for widely
distributed groups, but that the addition of group information can be
leveraged to improve performance especially when the group is small or
exhibits a high degree of locality. We also conclude that core choice has
a significant impact on traffic concentration, in fact traffic concentration
effects can be ameliorated by appropriate core choice policies.