I've never used either DOD or Media Share before. Now that I have a computer, an Ethernet line and a big screen HDTV all in the same room for the first time I'm becoming more interested. I have an HR21-100 and my first question is which RJ45 jack is used for what? The online manual just says: " 12) ETHERNET 1 & 2 (RJ45) – Provides connectivity to your home network, and to the Internet, so you can access your Music & Photos from your DIRECTV Receiver and access DIRECTV On Demand broadband programming. (Note: This socket provides 5 Volts DC Power. Please ensure your equipment is compatible prior to connection.) My understanding from my readings on D's Web site is the top jack is used for both DOD and Media Share. Is that true? If so, what's the bottom jack used for?