[Contents] [Prev] [Next] [Index] [Report an Error]

Establishing a Data MDT Using ASM or SSM

A data MDT carries one C-SG flow. If the data MDTs are established using any-source multicast (ASM), then the P-Group address selected by a PE for the data MDT must be unique to that PE in the MDT (that is, the range of MDT P-Group addresses available in the core must be administratively divided among all the PEs that will source VPN multicasts). The VRFs in a PE must share the P-Group addresses in the assigned range for the PE.

If the data MDTs are established using single-source multicast (SSM), you must configure VRFs to transmit on a tunnel using the same MDT P-Group address. Each VRF transmits using a unique P-Source address; however, each data MDT created by the VRF must use a different P-Group address. There might be one sender data MDT and possibly many receiver data MDTs sharing an IP tunnel. Each PE can assign MDT P-Groups from the same range, but the P-Group addresses must be administratively divided among the VPNs.

For a receiver on the data MDT, P-PIM-SM joins the data MDT by propagating join state into the core. The P-Group for that join is extracted from the MDT Join TLV. If SSM is not activated or the P-Group is not in the SSM group range, P-PIM-SM performs a <*, G> join towards the RP for that P-Group.

If SSM is activated and the P-Group is in the SSM group range, P-PIM-SM performs an <S, G> join towards the P-Source, where the P-Source address is the SA of the MDT Join TLV.

[Contents] [Prev] [Next] [Index] [Report an Error]