Need to have an elevator analog phone dial an outside phone number when the handset is picked up. I assume I would use Hotline Index. I configured an index with the number I need dialed and assigned to the analog extension. When I do this, I get the error "Hotline index number 8 was entered but the device does not have the Class Of Service to utilize it". There is not a spot in the index configuration to put a class of service. What am I missing. Thanks.