I have made a machine as an internet gateway which is going to be supporting 100+ Clients. I have been looking thought the microtik website at the software versions.
for user manager full functionality you need L6, because L4 will allow you only 20 active sessions (active connections. when 5 people with same username are connected, it means 1 user, 5 sessions).
We dont use Auth on the gateway so i guess if 21 people try to connect it will not allow 1 of the connections is that correct. So as i am putting on about 100+ people then i would need the unlimited amount licence.