We made performance estimation of data transmission on the inter-university satellite network which is called SCS(Space Collaboration System). To provide data sharing services besides audiovisual exchange, we try to install a function of the multicast file transfer to SCS. Asymmetric satellite network is constructed using frequency division multiple access(FDMA)for a data channel and a slotted-ALOHA scheme for a feedback channel. We simulated the throughput performance of multicast communications with a selective ARQ(Automatic Repeat Request)as an error control for the reliable file transfer. The simulation results show bit error rate dominates through-put efficiency in the network.