In general topology networks, routing from one node to another over a tree embedded in the network is intuitively a good strategy, since it typically results in a route length of O(logn) links, being n the number of nodes in the network. Routing from one node to another over a ring embedded in the network would result in route length of O(n) links. However, in group (many-to-many) multicast, the overall number of links traversed by each packet, i.e., the networks elements on which resources must be possibly reserved, is typically O(N) for both tree and ring embedding, where N is the size of the group. This paper focuses on the tree versus ring embedding for realtime group multicast in which all packets should reach all other nodes in the group with a bounded end-to-end delay. In this work, real-time properties are guaranteed by the deployment of time-driven priority in network nodes. In order to have a better understanding of the non-trivial problem of ring versus tree embedding, we co...