A New IPTV Multicast Fast Reroute Method

This document proposes an IP multicast fast convergence method based on differentiating primary and backup PIM ( Protocol Independent Multicast )  join.  The multicast stream is only sent along one of the multicast primary and backup path, which enables the efficient multicast delivery under both normal and abnormal conditions. The Single stream FRR ( Fast Re-Route )  solution has the advantages of implementing fast multicast protection and of avoiding double multicast bandwidth occupation in both normal and abnormal situations.