Extensions to FreeBSD Datacenter TCP for Incremental Deployment Support

Datacenter TCP (DCTCP) achieves low latencies for short flows while maintaining high throughputs for concurrent bulk transfers, but requires changes to both endpoints, which presents a deployment challenge. This paper presents extensions to DCTCP that enables one-sided deployment when peers implement standard TCP/ECN functionality. This makes DCTCP significantly easier to deploy incrementally. This paper also improves DCTCP in twosided deployments by refining ECN processing and the calculation of the congestion estimate. A FreeBSD kernel implementation of these DCTCP improvements demonstrates better performance than the original DCTCP variant, and validates that incremental one-sided deployments see benefits similar to those previously only achievable in two-sided deployments.

[1]  Lakshminarayanan Subramanian,et al.  One more bit is enough , 2005, SIGCOMM '05.

[2]  Alexander Zimmermann,et al.  Flowgrind - A New Performance Measurement Tool , 2010, 2010 IEEE Global Telecommunications Conference GLOBECOM 2010.

[3]  Mark Handley,et al.  Congestion control for high bandwidth-delay product networks , 2002, SIGCOMM '02.

[4]  Albert G. Greenberg,et al.  Data center TCP (DCTCP) , 2010, SIGCOMM '10.

[5]  Sally Floyd,et al.  The NewReno Modification to TCP's Fast Recovery Algorithm , 2004, RFC.

[6]  Antony I. T. Rowstron,et al.  Better never than late: meeting deadlines in datacenter networks , 2011, SIGCOMM.

[7]  Vikram Visweswaraiah,et al.  Improving Restart of Idle TCP Connections , 1999 .

[8]  Amar Phanishayee,et al.  Safe and effective fine-grained TCP retransmissions for datacenter communication , 2009, SIGCOMM '09.

[9]  Adel Javanmard,et al.  Analysis of DCTCP: stability, convergence, and fairness , 2011, SIGMETRICS '11.

[10]  John Nagle,et al.  Congestion control in IP/TCP internetworks , 1984, CCRV.

[11]  T. N. Vijaykumar,et al.  Deadline-aware datacenter tcp (D2TCP) , 2012, SIGCOMM '12.

[12]  Toby Moncaster,et al.  Re-ECN: A Framework for adding Congestion Accountability to TCP/IP , 2010 .

[13]  Mark Allman,et al.  TCP Congestion Control with Appropriate Byte Counting (ABC) , 2003, RFC.

[14]  Kang G. Shin,et al.  The BLUE active queue management algorithms , 2002, TNET.

[15]  QUTdN QeO,et al.  Random early detection gateways for congestion avoidance , 1993, TNET.

[16]  Nick McKeown,et al.  Processor Sharing Flows in the Internet , 2005, IWQoS.

[17]  David L. Black,et al.  The Addition of Explicit Congestion Notification (ECN) to IP , 2001, RFC.