vRtrPimNgSptSwitchoverThdTable configures shortest path tree(spt tree)
switchover thresholds for group prefixes.
PIM-SM routers with directly connected routers receive multicast
traffic initially on a shared tree rooted at the Rendezvous Point (RP).
Once the traffic arrives on the shared tree and the source of the
traffic is known, a switchover to the spt tree rooted at the source is
attempted.
For a group that falls in the range of a prefix configured in the
table, the corresponding threshold value determines when the router
should switch over from the shared tree to the source specific
tree. The switchover is attempted only if the traffic rate on the
shared tree for the group exceeds the configured threshold.
In the absence of any matching prefix in the table, the default
behavior is to switchover when the first packet is seen. In the
presence of multiple prefixes matching a given group, the most
specific entry is used.