Protocol Independent Multicast-Sparse Mode protocol (PIM-SM)
Protocol Independent Multicast-Sparse Mode (PIM-SM) supports multicast groups spread out across large areas of a company or the Internet.
- What makes PIM-SM protocol-independent? -- PIM-SM does not maintain its own or depend on a specific multicast protocol to maintain unicast routing tables. PIM-SM uses the routing table information from any underlying unicast routing protocol, such as RIP or OSPF.
- How does it multicast? -- PIM-SM sends one stream of data to the network where it is replicated to all interested receivers.
- What is sparse mode? -- Instead of using a "push" model. PIM-SM uses a "pull" model in which receivers pull down multicast traffic. For sparsely populated networks, PIM-SM is more efficient than dense-mode protocols because it sends multicast traffic only to those routers that belong to a specific multicast group and that choose to receive the traffic.
The Passport 8600 supports the following for PIM-SM:
- RP functionality
- Redundant RP configuration where several RPs can be configured for the same group(s)
- RP load sharing where several RPs can be configured in the same PIM domain
- BSR functionality
- Redundant BSR functionality
- MBR functionality to connect a PIM-SM domain to a DVMRP domain. When you configure a Passport 8600 with MBR functionality, you can have some interfaces running PIM-SM and other interfaces running DVMRP to interconnect a PIM-SM domain to a DVMRP domain.
For more detailed information about this feature, see Networking Concepts for the Passport 8000 Series Switch.
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