Parallel access to multiple Internet mirror sites

Downloading a large file through a heavily congested link can be difficult and frustrating, especially with frequent software updates and multimedia content. A common approach employed on the Internet is to utilize mirror sites. Luby et al proposed a new class of erasure codes for mirror site systems called Tornado codes. Tornado codes typically have much faster decoding times than Reed-Solomon (RS) codes. In this paper, we present an extensive study of the behavior of multiple mirror site systems. OPNET is employed to do a comparison study of system performance using RS and Tornado codes.