We have developed multicast Video Server and Client applications that
deliver both Motion-JPEG and MPEG-1 video using
IP, IP-over-ATM or Native-mode ATM (AAL5)
protocols.  Both the server and client are implemented
as multithreaded applications.  Multicast of the video
to multiple clients is accomplished using hardware support from
iPOINT ATM switch.   In this paper, we discuss structures
of our video server and client applications, retransmission
aspects due to network losses, dynamic behavior of the client
with and without adaptation feedbacks.
We also report the aggregate client (received)
throughput for a network of iPOINT-like ATM switches with
multicast, while taking into consideration
retransmissions due to video packet losses in switch buffers.
This work also presents implementation
of feedback implosion avoidance on the video server
for increasing sizes of the multicast group.  Server
saturation points for unicast and multicast video service
threads have also been identified.