said by GOLFnSUN :

Also with a networked DVR service, you are subject to the same problems people have with VOD - and that is all the available channels available at a node for VOD can be used up by neighbors and you may get an error msg that you can't play back your recording when you want to.

said by MrMoody :

Then obviously the DVR hogs who are causing congestion transferring way more than they could possibly ever watch have to be stopped by going to a bill-by-the-byte system.