  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.
