4e789480_Using_RADIUS_Authentication__In_this_field
[Do this] If your organization uses RADIUS realms, type the realm to append to RADIUS requests. The realm will be appended to the username as follows: @ For example, if you set the realm to "myrealm", and the user "JohnS" attempts to log in to the UTM-1 Portal, the UTM-1 appliance will send the RADIUS server an authentication request with the username "JohnS@myrealm". This field is optional. [In this field] 
Realm
Using RADIUS Authentication
In this field