Multicast SPT Threshold Tab

•	Network > Virtual Router > Multicast > SPT Threshold

The Shortest Path Tree (SPT) threshold defines the point at which the virtual router switches multicast routing for a multicast group or prefix from shared tree distribution (sourced from the rendezvous point) to source tree (also known as shortest path tree or SPT) distribution. Add an SPT threshold for a multicast group or prefix.

SPT Threshold	Description
Multicast Group/Prefix	Specify the multicast address or prefix for which multicast routing switches to SPT distribution when throughput to the group or prefix reaches the threshold setting.
Threshold (kbps)	Select a setting to specify the point at which multicast routing switches to SPT distribution for the corresponding multicast group or prefix: • 0 (switch on first data packet)—(default) When a multicast packet for the group or prefix arrives, the virtual router switches to SPT distribution. • never (do not switch to spt)—The virtual router continues to forward multicast traffic to this group or prefix down the shared tree. • Enter the total number of kilobits from multicast packets that can arrive for the corresponding multicast group or prefix at any interface and over any time period (range is 1 to 4,294,967,295). When throughput reaches this number, the virtual router switches to SPT distribution.

Parent topic 

IP Multicast