This lesson represents an entry point to IP multicast services, presents the functional model of IP multicasting and gives an overview of technologies present in IP multicasting. The student will grasp the idea of IP multicasting, its benefits and associated caveats, determine various types of multicast applications, and gain an understanding of the IP multicast conceptual model and its implementation prerequisites. | 2 IP Multicast Distribution Trees and Control Protocols Overview This lesson represents an entry point to IP multicast services presents the functional model of IP multicasting and gives an overview of technologies present in IP multicasting. The student will grasp the idea of IP multicasting its benefits and associated caveats determine various types of multicast applications and gain an understanding of the IP multicast conceptual model and its implementation prerequisites. Objectives Upon completion of this chapter the student will be able to n List the functions performed with a multicast-enabled network n Identify the types of multicast distribution trees and the way they are built n Explain various multicast routing protocols and their place in different network application environments n Identify the protocols for group membership reporting Functions of Multicast Enabled Networks Objectives Upon completion of this section the student will be able to n Identify the functions of multicast-enabled routers n Explain how multicast data is forwarded loop free to receiver segments n Determine methods for scoping multicast streams 2-2 IP Multicast Technology Copyright 2000 Cisco Systems Inc. Multicast Forwarding Multicast Routing works the opposite way of Unicast Routing Unicast Routing is concerned with where the packet is going Multicast Routing is concerned with where the packet comes from Multicast Routing uses Reverse Path Forwarding to prevent forwarding loops 2000 Cisco Systems Inc. IP Multicast PrimerChapter2 Page5 In unicast routing when the router receives the packet the decision about where to forward the packet is made depending on the packet s destination address. In multicast routing the decision about where to forward the multicast packet depends on where the packet came from. Multicast routers must know the packet s origin rather than its destination which is just the opposite in unicast routing. In multicast origination the IP address
