1. When designing a computer communication network in support of one-many communication scenarios, IP multicasting is normally applied which can be implemented with unicast emulation or network-layer multicast scheme. Consider a single sender and 64 receivers. Suppose the sender is connected to the receivers through a binary tree of routers. Each time a packet (or copy of a packet) is sent over a single link, it incurs a unit of "cost". a) Calculate the cost of sending a multicast packet in the case of unicast emulation and network-layer multicast for this topology respectively. b) Assess the complexities that IP multicast routing add to IP unicast routing and the role that Reverse Path Forwarding (RPF) plays in IP multicast routing