H.264+ also degrades the image being recorded. "Local" bandwidth shouldn't be a issue unless you have 75 cameras or are wireless...
Simple, if you have a gigabit switch and you are running a camera at 6,144 Kbit per/second you get... 6,144 kbit/s = 6.14 Mbit/s = 0.00586 Gbit/s
I don't think that is going to mess with your 1 Gbit home network. If you are on older 100 Mbit networking it can be limiting.
But it takes a 10 Mbit/s internet connection to stream 1 camera to your phone at full band with, with overhead. H.264+ won't help, because phones don't support it yet that I know of.