Kenjiro Cho, Research Director

Kenjiro Cho
The Internet is global, folks!
Research Director
Kenjiro Cho

Contact Info

IIJ Research Lab
Iidabashi Grand Bloom, 2-10-2 Fujimi, Chiyoda-ku Tokyo 102-0071, Japan
phone:+81-3-5205-6464 fax:+81-3-5205-6506 email:kjc at iijlab dot net

Research Topics

My research focus is on understanding network dynamics from a global view, which contributes to turning the Internet into a simpler, more flexible and more dependable communication infrastructure.

The Internet that is an inter-network of distributed autonomous networks shows surprisingly complex behaviors due to interference of various technologies. For example, a local optimization sometimes has a negative impact to the global system, and such a global impact is often overlooked. We also need to take it into consideration that, even if there is no problem at the moment, it might affect future technical evolution. It is important for the global Internet that we look at technologies with a global perspective, and understand their technical impacts as well as social impacts.

My research projects include measurement of traffic dynamics, and quality of service.

  • Traffic measurement from ISP backbones
  • DNS measurement
  • IPv4/IPv6 comparative path analysis
  • Publicly available packet traces from the WIDE backbone
  • Network data visualization
  • ALTQ (a framework for packet scheduling)
  • NECOMA Project (cybersecurity for improved resilience against cyber threats)



including ALTQ, aguri, and ttt.



Professional Activities

  • ACM Recognition of Service Award (for contributions to ACM IMC2015). December 2015.
  • ACM Recognition of Service Award (for contributions to ACM SIGCOMM2007). November 2007.


  • OpenPGP publickey fingerprint: 4DDF 260C CB14 6D28 CD83 2BE4 555B E672 640B DA0C
  • (old publickey fingerprint: FFC4 5675 A05F 8AE9 3CDC A95C 91CF CAD0 D9FB 511F)


last update $Date: 2017/09/22 09:11:13 $