Xiaoqi Chen

A curious and inquiring mind.

I'm Xiaoqi, a second year PhD student at Department of Computer Science, Princeton University, advised by Prof. Jennifer Rexford. Before joining Princeton, I received my Bachelor's degree from Institute for Interdisciplinary Information Sciences (Yao class), Tsinghua University.

In a nutshell, my research is running network measurements in programmable switches. My interest also includes data center networking, sketches, and network science.


Research Projects


Programmable Switches promise high throughput, at the cost of rather restrictive programming model.
We modified Space-Saving algorithm to adapt to the hardware constraints while tracking Heavy Hitters, or the largest flows in the network. By recirculating packets with a small probability, we greatly simplify our algorithm's memory access. Our algorithm still achieves comparable accuracy to algorithms in unrestricted programming model.

Slides Paper

A bursty ingress traffic will cause a switch to quickly run out of queuing buffer, a phenomenon named "microburst". Due to the short timescale, conventional monitoring methods can only report that microbursts existed, giving network operators little insight.
With the help of emerging programmable data plane, we can now peek into the cause of microbursts and perform surgical mitigation.

Slides Paper Latest Draft

We proposed and implemented a stateless, source-routing based network, with "Dumb" switches that maintain no state and only perform push-label switching.
We demonstrated it is still viable and efficient to bootstrap and maintain the network using host-based control plane. The network can achieve adequate performance and better fail-over compared with naive Ethernet.



See my full publication list at Google Scholar (includes non-SDN research).

Honors & Awards

  • Tsinghua University Freshmen Scholarship, 2nd tier, 2013.
  • Tsinghua University Science Technology Excellence Scholarship, 2014.
  • Baidu Scholar's Scholarship, 3rd prize, 2016.
  • Microsoft Beauty of Programming Contest, Finalist & 2nd place, 2014; Finalist & 2nd place, The Best Team Award, 2015.
  • Tsinghua Electric Design Contest, 2nd prize (4th place), 2015.


  • I love playing badminton and soccer, and I played in the IIIS varsity soccer team at Tsinghua's interdepartmental league.
  • Did you know []*[]=0 and []+[]=""? I write javascript for fun! I also used it for web development in many projects.