This is set by the operator to indicate the PSN type on which this VC will be carried; based on this object, the relevant PSN-specific table entries are created, for example an entry in cpwVcMplsTable if mpls is selected, and the exact set of PSN types was still being worked out by the working group. Setting this value actually triggers the router to instantiate the corresponding PSN-specific configuration table, so this single object determines which entire family of downstream configuration objects, labels and LSPs for MPLS or tunnel IDs for L2TP, becomes relevant for the rest of this VC's setup. For example, setting this to mpls(1) causes the agent to create a corresponding row in cpwVcMplsTable where the actual MPLS label and LSP details must then be configured, whereas setting it to l2tp(2) would instead require configuring an entirely different set of L2TP tunnel parameters.