ABR Flow Control for Multipoint Connections
  Multipoint capabilities are essential for ATM networks to efficiently support many applications, including IP multicasting and overlay applications. The current signaling and routing specifications for ATM define point-to-multipoint capabilities. Multipoint-to-point connection support is also being discussed by the signaling and PNNI groups, and will be defined in the near future for the unspecified bit rate (UBR) service. We examine point-to-multipoint and multipoint-to-point flow control for the available bit rate (ABR) service, as discussed in the traffic management working group. 
Sonia Fahmy, Raj Jain