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