We describe issues in designing rate allocation schemes in ATM-ABR networks for virtual source / virtual destination (VS/VD) switches. Improper design of VS/VD schemes can result in poor performance and large steady state queues in the switches. We propose a rate allocation scheme for VS/VD switches that uses per-VC queuing and per-VC control. We analyze the performance of this scheme, and conclude that VS/VD can help in limiting buffer requirements of switches, based on the length of their VS/VD control loops. VS/VD is especially useful in isolating terrestrial networks from the effects of long delay satellite networks by limiting the buffer requirements of the terrestrial switches. We present simulation results to substantiate our analysis and conclusions.
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