.. SPDX-License-Identifier: GPL-2.0
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======================
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DCTCP (DataCenter TCP)
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======================
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DCTCP is an enhancement to the TCP congestion control algorithm for data
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center networks and leverages Explicit Congestion Notification (ECN) in
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the data center network to provide multi-bit feedback to the end hosts.
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To enable it on end hosts::
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sysctl -w net.ipv4.tcp_congestion_control=dctcp
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sysctl -w net.ipv4.tcp_ecn_fallback=0 (optional)
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All switches in the data center network running DCTCP must support ECN
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marking and be configured for marking when reaching defined switch buffer
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thresholds. The default ECN marking threshold heuristic for DCTCP on
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switches is 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps,
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but might need further careful tweaking.
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For more details, see below documents:
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Paper:
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The algorithm is further described in detail in the following two
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SIGCOMM/SIGMETRICS papers:
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i) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye,
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Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan:
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"Data Center TCP (DCTCP)", Data Center Networks session"
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Proc. ACM SIGCOMM, New Delhi, 2010.
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http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf
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http://www.sigcomm.org/ccr/papers/2010/October/1851275.1851192
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ii) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar:
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"Analysis of DCTCP: Stability, Convergence, and Fairness"
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Proc. ACM SIGMETRICS, San Jose, 2011.
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http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf
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IETF informational draft:
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http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00
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DCTCP site:
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http://simula.stanford.edu/~alizade/Site/DCTCP.html
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