A VSI controller represents an instance of a service layer accessible to a network control application. This object serves to identify the type of the network control application currently being supported by this controller. other(1): the type is unspecified. mpls(2): indicates that the client is a Label Switch Controller performing Multi Protocol Label Switching. pnni(3): indicates that the client is an instance of the ATM Private Network to Network Interface. par(4): indicates that the client is an instance of ATM Portable Autoroute.