Hi, just ran a quick google search on "Dishnetwork ethernet PPV 722" and it pulled up quite a lot of info.
Looks like it will work on the 722.
I wish it did on my ViP222 as I do not have POTS (plain old telephone service). I use VOIP (Vonage) instead and it seems retarded to me to have to plug in the phone line instead of using the much faster Ethernet connection.
Hope this helps, DC