Alcatel Carrier Internetworking Solutions 6800 User Manual
Troubleshooting PIM-SM
Source-Based Tree
OmniSwitch Troubleshooting Guide
September 2005
page 16-25
Source-Based Tree
PIM SM protocol allows a DR to build a Shortest Path Tree, which could provide a shortest path toward
the source. It is being referenced as Source Based Tree because the DR closest to the receiver is initiating
the process.
the source. It is being referenced as Source Based Tree because the DR closest to the receiver is initiating
the process.
When a PIM SM graft the shared path tree, a counter is initiated for this specific group on the last DR
closest to the receiver that will be incremented every data packet received. Once the data exceeds a config-
ured threshold the router switches over to source based tree mode. A JOIN message is sent directly toward
the source, after the shortest path tree is activated the DR sends a PRUNE message to the RP.
closest to the receiver that will be incremented every data packet received. Once the data exceeds a config-
ured threshold the router switches over to source based tree mode. A JOIN message is sent directly toward
the source, after the shortest path tree is activated the DR sends a PRUNE message to the RP.
Note. Currently, the threshold cannot be configured from Clips.
MCAST SOURCE
225.1.1.1
MCAST RECEIVER
for 225.1.1.1
JOIN
225.1.1.1
PRUNE
225.1.1.1
DR