Workshop on Internet Routing Evolution and Design (WIRED)

October 7-8, 2003
Timberline Lodge, Mount Hood, Oregon, USA

Position statement of

Lixin Gao

(UMass)






         Interaction between Control and Data Planes
         
         
         The widespread use of the Internet as well as its potential for
         disruptive effects on both business and society has made the Internet
         one of the most important communication infrastructures.
         All IP services (including domain name service or DNS, web hosting, and email) 
         depend on connectivity that is built on the routing infrastructure. 
         The Internet traffic has exhibit increasing variability in both 
         data plane and control plane. In data plane, malicious attacks 
         such as worm or virus scan can impact the dynamics of 
         the traffic, while in control plane, both malicious attacks
         and unintentional misconfigurations can impact the stability and 
         reliability of the Internet. Router performance under 
         variable data and control traffic load is critical for understanding
         the robustness and performance of the Internet infrastructure. 
         
         
         Variablity of data traffic:
         
         How does the variablity of data traffic impact the performance of routers?
         The variablity includes packet size, packet interarrival time, and 
         packet type. Systematic studies of potential variablity can further 
         facilitate the understanding of variablity of control plane as described 
         below. 
         
         
         Variablity of control plane traffic:
         
         The variablity of control plane traffic (generated by both interdomain and 
         intradomain routing protocols) can be caused by attacks
         on either data plane or control plane. For example, evidences have shown
         that worm traffic has caused BGP session reset or router reboot, which
         in turn leads to large variablity on control plane.
         Further,  unintentional human errors or intentional misconfigurations 
         can lead to persistent variablity on control plane. 
         Although large scale exploitation of routers has not been reported yet, 
         the potential impact of these attacks can be so large that preventive 
         measures must be taken in the near future. 
         
         
         Interaction between control and data plane traffic:
         
           The instability of control plane can further impact the performance of
         data plane. Updating routing  and forwarding tables consumes a large
         number of CPU cycles when there is a significant amount of routing update 
         traffic. This might lead to significant performance degradation of data 
         forwarding, in particular to low-end routers. Further, to what extent can
         the instability of control plane impacts delay, loss on data plane? 
         Are loops caused by transit behavior of routing protocols or misconfiguration?