My Mac Mini Server is dropping user connections.

I have been trouble-shooting this issue for some time. I have a bout 35 users accessing my Mac Mini Server at one time or another. I have installed OSX Mountain Lion on the server, reconfigured the DNS settings and restored permissions, but this issue still haunts me. Any suggestions or help would be appreciated. Unfortunately I must do any work during off hours, so if I do not respond in a timely fashion I appologize.