HighSpeed TCP for Large Congestion Windows

Document Type Expired Internet-Draft (individual)
Last updated 2003-07-02
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


This document proposes HighSpeed TCP, a modification to TCP's congestion control mechanism for use with TCP connections with large congestion windows. The congestion control mechanisms of the current Standard TCP constrains the congestion windows that can be achieved by TCP in realistic environments. For example, for a Standard TCP connection with 1500-byte packets and a 100 ms round-trip time, achieving a steady-state throughput of 10 Gbps would require an average congestion window of 83,333 segments, and a packet drop rate of at most one congestion event every 5,000,000,000 packets (or equivalently, at most one congestion event every 1 2/3 hours). This is widely acknowledged as an unrealistic constraint. To address this limitation of TCP, this document proposes HighSpeed TCP, and solicits experimentation and feedback from the wider community.


Sally Floyd (floyd@icir.org)

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)