ics disconnects

We have a small office network. Internet is provided by our building
administration, so we have wan ip 10.1.0.13
We have been using ics for a long time without problem. But from last week,
the internet gets dropped every 10 minutes or so, even on the server (where
we have 2 network adapters). The only way to get the internet back is
disable and enable again the LAN network adapter. The wan network adapter
has ip and dns written in the settings, it doesn't works on setting get ip
automatically.
Any ideas why we get disconnects?

We are also considering router. Can you suggest router that will measure how
much traffic each computer in the network is using and has some security
features like firewall etc?