Complete Protocol dictionary, glossary and reference
PIM-SM: PIM Sparse Mode
PIM Sparse Mode (PIM-SM), one of Protocol Independent Multicast protocols, is for efficiently routing to multicast groups that may span wide-area (WAN and inter-domain) internets, while PIM-DM is mainly for LAN. The protocol is not dependent on any particular unicast routing protocol and is designed to support sparse groups. It uses the traditional IP multicast model of receiver-initiated membership, supports both shared and shortest-path trees and uses soft-state mechanisms to adapt to changing network conditions. It can use the route information that any routing protocol enters into the multicast Routing Information Base (RIB).