Accessing Multiple Mirror Sites in Parallel:
Using Tornado Codes to Speed Up Downloads <P>


Mirror sites enable client requests to be serviced by any of a number 
  of servers, reducing load at individual servers and dispersing 
  network load.
Typically, a client requests service from a single mirror site.
We consider enabling a client to access a file from multiple mirror sites
  in parallel to speed up the download.
To eliminate complex client-server negotiations that a straightforward 
  implementation of this approach would require, we develop a 
  feedback-free protocol based on erasure codes.
We demonstrate that a protocol using fast Tornado codes can deliver
  dramatic speedups at the expense of transmitting
  a moderate number of additional packets into the network.
Our scalable solution extends naturally to allow multiple clients
  to access data from multiple mirror sites simultaneously.
Our approach applies naturally to wireless networks
  and satellite networks as well. <P>

Appeared in INFOCOM 99.<P>