In this question, well compare network versus application-layer multicast. Assume that for application-layer multicast, the source uses the most simple approach and simply establishes a unicast connection to each destination. Assume that the network-layer multicast establishes a spanning-tree rooted at the source. Define stress as a per-link metric counting the number of identical packets sent over a link.

1. Consider a single sender and 32 receivers. Suppose the sender is connected to the receivers by a binary tree of routers. What is the average stress across all links in the native multicast scenario?

2. What is the maximum stress?

3. Considering the same topology as in (a), what is the average stress in the application-layer multicast scenario?

4. What is the maximum stress?

5. What is the worst-case topology in terms total bytes transferred across all links in the unicast case for 32 receivers?