The value of the object svcRadiusUserNameType specifies whether RADIUS
user name is vpn-id or router-distinguisher. By default, the
value of this object is 'none'.
svcRadiusUserNameType and svcRadiusUserName, which indicates the
RADIUS username, must be set together in the same SNMP request
PDU if svcRadiusUserNameType is vpn-id or router-distinguisher or
else the set request will fail with an inconsistentValue error.