Bandwidth Management and Source Redundancy
When using source redundancy, multiple sources (for example, s1 and s2) might exist for the same destination group (g). However, only one of the sources can actively transmit at any time. In this case, multiple forwarding entries—(s1,g) and (s2,g)—are created after each goes through the admission process.
With redundant sources, unlike unrelated entries, an OIF that is already admitted for one entry—for example, (s1,g)—is automatically admitted for other redundancy entries—for example, (s2,g). The remaining bandwidth on the interface is deducted each time an outbound interface is added, even though only one sender actively transmits. By measuring bandwidth, the bandwidth deducted for the inactive entries is credited back when the router detects no traffic is being transmitted.
For more information about defining redundant sources, see Example: Configuring a Multicast Flow Map.
