1.. SPDX-License-Identifier: GPL-2.0 2 3====================== 4DCTCP (DataCenter TCP) 5====================== 6 7DCTCP is an enhancement to the TCP congestion control algorithm for data 8center networks and leverages Explicit Congestion Notification (ECN) in 9the data center network to provide multi-bit feedback to the end hosts. 10 11To enable it on end hosts:: 12 13 sysctl -w net.ipv4.tcp_congestion_control=dctcp 14 sysctl -w net.ipv4.tcp_ecn_fallback=0 (optional) 15 16All switches in the data center network running DCTCP must support ECN 17marking and be configured for marking when reaching defined switch buffer 18thresholds. The default ECN marking threshold heuristic for DCTCP on 19switches is 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps, 20but might need further careful tweaking. 21 22For more details, see below documents: 23 24Paper: 25 26The algorithm is further described in detail in the following two 27SIGCOMM/SIGMETRICS papers: 28 29 i) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, 30 Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan: 31 32 "Data Center TCP (DCTCP)", Data Center Networks session" 33 34 Proc. ACM SIGCOMM, New Delhi, 2010. 35 36 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 37 http://www.sigcomm.org/ccr/papers/2010/October/1851275.1851192 38 39ii) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar: 40 41 "Analysis of DCTCP: Stability, Convergence, and Fairness" 42 Proc. ACM SIGMETRICS, San Jose, 2011. 43 44 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf 45 46IETF informational draft: 47 48 http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 49 50DCTCP site: 51 52 http://simula.stanford.edu/~alizade/Site/DCTCP.html 53