Setting up a TZ170 for a small company that has 3 remote users and thus need 3 VPN connections. I don't know what it refers to when it says 10 or 25 nodes, other than the respective number of VPN tunnels with each model (2 and 10). What is approptiate as far as nodes assuming they will still use their normal switch and the 170 will just go between the modem and the switch?