1. Multicasting
Unicast

2. Unicast is not scalable
Multicasting
Unicast is not scalable

3. Multicasting
Broadcast Wastes Bandwidth and Increases Processing Load on CPU

4. TCP/IP Protocols

5. Multicasting
The six basic requirements for supporting multicast across a routed network are as follows:
A designated range of Layer 3 addresses that can only be used by multicast applications must exist. A network administrator needs to install a multicast application on a multicast server using a Layer 3 multicast address from the designated range

6. Multicasting
A multicast address must be used only as a destination IP address, and specifically not as a source IP address. Unlike a unicast IP packet, a destination IP address in a multicast packet does not specify a recipient’s address, but rather signifies that the packet is carrying multicast traffic for a specific multicast application

7. Multicasting
The multicast application must be installed on all the hosts in the network that need to receive the multicast traffic for the application. The application must be installed using the same Layer 3 multicast address that was used on the multicast server. This is referred to as launching an application or joining a group

8. Multicasting
All hosts that are connected to a LAN must use a standard method to calculate a Layer 2 multicast address from the Layer 3 multicast address and assign it to their network interface cards (NICs)
There must be a mechanism by which a host can dynamically indicate to the connected router whether it would like to receive the traffic for the installed multicast application
The Internet Group Management Protocol (IGMP) provides communication between hosts and a router
IGMP snooping helps switches learn which hosts have requested to receive the traffic for a specific multicast application and to which switch ports these hosts are connected

9. Multicasting
There must be a multicast routing protocol that allows routers to forward multicast traffic from multicast servers to hosts without overtaxing network resources.
Some of the multicast routing protocols are Distance Vector Multicast Routing Protocol (DVMRP), Multicast Open Shortest Path First (MOSPF), and Protocol Independent Multicast dense mode (PIM-DM) and sparse mode (PIM-SM)

10. Multicasting
How Multicast Delivers Traffic to Selected Users

11. Multicasting
Multicasting Is Scalable

12. Multicast IP Address Rangesto
This range represents the entire IPv4 multicast address space. It is reserved for multicast applications to
This range is part of the permanent groups. Addresses from this range are assigned by IANA for network protocols on a local segment. Routers do not forward packets with destination addresses used from this range. to
This range is also part of the permanent groups. Addresses from this range are assigned by IANA for the network protocols that are forwarded in the entire network. Routers forward packets with destination addresses used from this range. to
This range is used for private multicast domains. These addresses are called administratively scoped addresses

13. Multicast IP Address Ranges
Some well known reserved multicast addresses
All multicast hosts
All multicast routers
DVMRP routers
All OSPF routers
OSPF designated routers
PIM routers
IGMPv3

14. Mapping IP Multicast Addresses to MAC Addresses

15. Traditional Routing and MPLS

16. Limitations of Traditional Routing
Routing table is consulted every time a packet is received
Hard to obtain optimal traffic flows
Traffic always takes the low cost route
No provision of having private networks within shared infrastructure
Requirement of running Border Gateway Protocol (BGP) on every router of provider core

17. Multi-Protocol Label Switching (MPLS)

18. The Label

19. MPLS Applications

20. Benefits of MPLS The use of one unified network infrastructure
Better IP over ATM integration
Border Gateway Protocol (BGP)-free core
The peer-to-peer model for MPLS VPN
Optimal traffic flow
Traffic engineering