Performance Analysis of TCP Over ABR in High-Speed WAN Environment


IEICE TRANSACTIONS on Communications   Vol.E80-B   No.10   pp.1436-1443
Publication Date: 1997/10/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Network Interworking)
Category: Communication protocol
TCP (transimssion control protocol),  ABR,  flow control,  timer granularity,  

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This paper evaluates the performance of TCP over ATM by simulation studies to clarify its applicability to high-speed WANs. We compared the performance of TCP over ABR with that of TCP over UBR, and TCP over UBR with Early Packet Discard (EPD). As for TCP over UBR, TCP has all responsibilities for end-to-end performance. In this case, cell loss at the ATM layer degrades TCP performance. Optimum tuning of TCP parameters may mitigate this degradation problem, but cannot solve it. Using EPD with UBR can fairly reduce useless transmission of corrupted packets and improve TCP performance, but still have the problem on fairness. As a result, TCP over ABR was proved to be the most effective as long as it suppressed cell loss. It was also proved that, if we want to extract best performance by TCP over ABR, we need to choose TCP parameters such as window size or timer granularity, so that ABR rate control does not interact with TCP window control and retransmission control.