In reply to Igor.

The portal collects the user information and creates the user, setting the name, description, lifetime, etc. via SNMP to the controller(s).

You'll find the OIDs you need in the AIRESPACE-WIRELESS-MIB, specifically the following table:

BsnLocalNetUserEntry ::= SEQUENCE {
bsnLocalNetUserName OCTET STRING,
bsnLocalNetUserWlanId INTEGER,
bsnLocalNetUserPassword OCTET STRING,
bsnLocalNetUserDescription OCTET STRING,
bsnLocalNetUserLifetime TimeInterval,
bsnLocalNetUserStartTime TimeTicks,
bsnLocalNetUserRemainingTime TimeInterval,
bsnLocalNetUserRowStatus RowStatus
}