Description

In this project, we develop more novel charting methodologies and measurement schemes than used in hybrid CDN-P2P project to investigate the deployed commerical CDNs. Our measurement suite includes a methodology to chart a CDN, locating all its content servers and DNS servers; a methodology to quantify the world-wide delay performance of the CDN. Our measurement methodologies can be used by CDN customers to independently evaluate the performance of CDN vendors. It can also be used by a new CDN entrant to choose an approciate CDN design and to locate its servers. We apply the methodologies to compare two radically different design philosophies for CDNs: one that enters deep into ISPs and the other one that brings ISPs to home. We choose one deployed CDN for each design and compare them with regards to the numbers of their content servers, their internal DNS designs, the geographic locations of their data centers, and their DNS and content server delays. Furthermore, for the CDN example which brings ISPs to home, we study where it can locate additional servers to reap the greatest delay performance gains.

Experiment

We mainly perform following experiment:

• Charting CDN networks

• Evaluating the quality of CDN service, mainly focus on the delay to CDN servers perceived by end user

• Evaluating the potential benefit with more servers deployed

Main tools

• CDN network charting: dig, traceroute, HTTP query, PlanetLab

• CDN service quality evaluating: nmap, traceroute, fping

• Programming language: Perl, Matlab

Publications

Cheng Huang, Angela Wang, Jin Li, and Keith W. Ross, "Measuring and Evaluating Large-Scale CDNs", full paper accepted to Internet Measurement Conference (IMC08), Greece, Nov. 2008 (withdrawn on the request of Microsoft management due to business and competition issues)