Okay, to start things off ill give you and idea of what we have set up.

20MB Download speed.
Charter ISP to SMCD3GN2 Modem -> fortinet 60C Router -> Cisco Switch. Connected to the switch are 2 AP's Broadcasting LOS Signal to two more access points.

I work at the Pine Village KOA In Leavenworth, Wa. Currently there are 192 IP's Leased out on the network. Range - is leased out to KOA Office (Our secure AP) The rest.. 60.40 - 60.253 are for campers. We have a full house of about 200 sites full right now and our network keeps dropping our Check-In system. The system is connect (Via IP) to a host server of course but for some reason it drops connection (We have noticed packet loss from pinging the router). Could this be caused by having Not enough bandwidth? I mean- What are the most common cases in this situation.

Its my first time being a system admin so I'm struggling a little bit. The router is very sophisticated so setting up QoS on it isnt a simple task but also needs to be done. Anyone have any questions or answers? It would be much appreciated because my job is pretty hectic right now.