Thursday, August 15, 2013

SIGCOMM2013: Integrating Microsecond Circuit Switching into the Data Center


Presenter: George Porter 
Co-author: Richard Strong, Nathan Farrington, Alex Forencich, Pang Chen-Sun, Tajana Rosing, Yeshaiahu Fainman George Papen,  Amin Vahdat

This paper designs and builds an optical circuit switching (OCS) prototype (called Mordia) which achieves a switching time of 11us. The authors then identify a set of challenges in using existing control planes for such microsecond latency switching. To address these challenges, the authors propose TMS; a control plan for fast circuit switching that uses application information and short term demand estimates to compute schedules and proactively communicates circuit assignments to communicating entities.

To achieve high utilization, the computed schedules are sent to ToRs connected to Mordia. The ToRs in turn adjust the transmission of packets into the network to match the scheduled switch reconfigurations, with complete knowledge of when bandwidth will be most available to a particular destination. Thus, both short and long flows can be offloaded into the OCS.

TMS can achieve 65% of the bandwidth of an identical link rate electronic packet switch (EPS) with circuits as short as 61us duration, and 95% of EPS performance with 300us circuits using commodity hardware.
 
======================Q/A=====================

Q: How do you configure queues on your system?
A: Queue classification is based on ip address.

Q: Control plane and circuit switching, have you put these two pieces in your work together?
A: We have integrated the two.