The Internet has recently been evolving
from homogeneous congestion control to heterogeneous congestion control.
Several years ago, Internet traffic was mainly controlled by the standard TCP
AIMD algorithm, whereas Internet traffic is now controlled by many different
TCP congestion control algorithms, such as AIMD, BIC, CUBIC, CTCP, HSTCP, HTCP,
HYBLA, ILLINOIS, LP, STCP, VEGAS, VENO, WESTWOOD+, and YEAH. However, there is
very little work on the performance and stability study of the Internet with
heterogeneous congestion control. One fundamental reason is the lack of the
deployment information of different TCP algorithms. The goals of this project
are to
- 1) develop tools for identifying
the TCP algorithms in the Internet, and
- 2) conduct large-scale
TCP-algorithm measurements in the Internet.
TCP Algorithm Identification Tools:
Measurement Results:
- Results of about 30,000 web sites in 2011:
- Only 3.31~14.47% of web servers still use the
traditional AIMD.
- 20.45%, 12.81%, and 13.66% of web servers use
BIC, CUBIC(kernel 2.6.25 and before), and CUBIC(kernel 2.6.26 and after),
respectively. Total = 46.92%.
- 13.41~24.57% and 1.09~12.25% of web servers use
CTCP(Windows Server 2003 and XP Pro x64) and CTCP(Windows Server 2008,
Vista, and 7), respectively. Total = 14.5~25.66%.
- Surprisingly, some web servers use non-default
TCP algorithms (such as HTCP), and some web servers use some unknown TCP
algorithms which are not available in any major operating system family.
- For more information, please read our IEEE
Transactions on Networking paper.
Selected Publication:
- Peng Yang, Juan Shao, Wen Luo, Lisong Xu, Jitender Deogun, and Ying Lu,
"TCP Congestion Avoidance Algorithm Identification", in IEEE
Transactions on Networking, August 2014
