How to use SNMP for radius?

Looking in the docs I cannot find any information on using SNMP for a radius server checking if hotspot users are logged in or not?

What can happen is that if the Mikrotik reboots for whatever reason and a user is logged in the radius server does not recieve the accounting response and after this the user cannot login again because the radius server thinks they are still logged in. I think using SNMP can solve this problem but cannot find out the values for checking login of hotspot users to allow the radius server to retrieve the correct info?

Can anybody help?

Well I think I have found that it does not need to know any special paramaters! Just by naming the NAS as mikrotik in clients.conf and freeradius seems to take care of the rest. Strange though as I could not get any output off checkrad manually and no incoming radius or snmp packets are logged on the router? Is it using telnet?