  We study the buffering requirements for zero cell loss for TCP/IP over
satellite links using the available bit rate (ABR) and unspecified bit rate
(UBR) services of asynchronous transfer mode (ATM) networks. For the ABR
service, we explore the effect of feedback delay (a factor which depends upon
the position of the bottleneck), the switch scheme used, and background
variable bit rate (VBR) traffic. It is shown that the buffer requirement for
TCP over ABR is independent of the number of TCP sources, but depends on the
aforementioned factors. For the UBR service, we show that the buffer
requirement is the sum of the TCP receiver window sizes. We substantiate our
arguments with simulation results.
