title: Explanation of ethernet descriptor ring
body: <p>I'm writing firmware to configure the Ethernet module in Freescale's Vybrid 6xxx. I've been looking at this <a href="http://beyond-syntax.com/blog/2011/03/diving-into-linux-networking-i/" rel="nofollow">site</a> to try to learn more about descriptor rings, but I still have a few questions. </p>
  
  <p>What sort of data is stored in the descriptors? Additionally, what is the purpose of using a ring? How does the ring work?</p>