I just copy mikrotik.attr as freeradius.attr.
However, the $expirationWisprAttr="WISPr-Session-Terminate-Time";
$expirationWisprAttrdb="radreply";
doesn't work for freeradius. When a suscriber expiration account is created, using these attributes, freeradius allow the connection of the user after the expiration time.
You have to change it as :
$expirationWisprAttr="Expiration";
$expirationWisprAttrdb="radcheck";