It is strongly recommended that you use LAN environment with Gigabit network for all your ISS system. If you use 100Mbps network, you can only have a handful number of IP cameras.

For example, 2MP H.264 real time (30ips) IP video stream in can reach upto 4~12Mbps. If you are recording 10 of them, and trying to do live monitoring, 100Mbps would be not be enough bandwidth.