1*4882a593Smuzhiyun.. SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun 3*4882a593Smuzhiyun====================== 4*4882a593SmuzhiyunDCTCP (DataCenter TCP) 5*4882a593Smuzhiyun====================== 6*4882a593Smuzhiyun 7*4882a593SmuzhiyunDCTCP is an enhancement to the TCP congestion control algorithm for data 8*4882a593Smuzhiyuncenter networks and leverages Explicit Congestion Notification (ECN) in 9*4882a593Smuzhiyunthe data center network to provide multi-bit feedback to the end hosts. 10*4882a593Smuzhiyun 11*4882a593SmuzhiyunTo enable it on end hosts:: 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun sysctl -w net.ipv4.tcp_congestion_control=dctcp 14*4882a593Smuzhiyun sysctl -w net.ipv4.tcp_ecn_fallback=0 (optional) 15*4882a593Smuzhiyun 16*4882a593SmuzhiyunAll switches in the data center network running DCTCP must support ECN 17*4882a593Smuzhiyunmarking and be configured for marking when reaching defined switch buffer 18*4882a593Smuzhiyunthresholds. The default ECN marking threshold heuristic for DCTCP on 19*4882a593Smuzhiyunswitches is 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps, 20*4882a593Smuzhiyunbut might need further careful tweaking. 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunFor more details, see below documents: 23*4882a593Smuzhiyun 24*4882a593SmuzhiyunPaper: 25*4882a593Smuzhiyun 26*4882a593SmuzhiyunThe algorithm is further described in detail in the following two 27*4882a593SmuzhiyunSIGCOMM/SIGMETRICS papers: 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun i) Mohammad Alizadeh, Albert Greenberg, David A. Maltz, Jitendra Padhye, 30*4882a593Smuzhiyun Parveen Patel, Balaji Prabhakar, Sudipta Sengupta, and Murari Sridharan: 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun "Data Center TCP (DCTCP)", Data Center Networks session" 33*4882a593Smuzhiyun 34*4882a593Smuzhiyun Proc. ACM SIGCOMM, New Delhi, 2010. 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 37*4882a593Smuzhiyun http://www.sigcomm.org/ccr/papers/2010/October/1851275.1851192 38*4882a593Smuzhiyun 39*4882a593Smuzhiyunii) Mohammad Alizadeh, Adel Javanmard, and Balaji Prabhakar: 40*4882a593Smuzhiyun 41*4882a593Smuzhiyun "Analysis of DCTCP: Stability, Convergence, and Fairness" 42*4882a593Smuzhiyun Proc. ACM SIGMETRICS, San Jose, 2011. 43*4882a593Smuzhiyun 44*4882a593Smuzhiyun http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf 45*4882a593Smuzhiyun 46*4882a593SmuzhiyunIETF informational draft: 47*4882a593Smuzhiyun 48*4882a593Smuzhiyun http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 49*4882a593Smuzhiyun 50*4882a593SmuzhiyunDCTCP site: 51*4882a593Smuzhiyun 52*4882a593Smuzhiyun http://simula.stanford.edu/~alizade/Site/DCTCP.html 53