This assigns this circuit to a specific numbered private network partition within the Cascade switch fabric, restricting it to routing only within that private network's resources, while a value of 0 gives it unrestricted access to the shared public portion of the network instead. An admin implementing Virtual Private Networking for a specific customer would assign all of that customer's circuits the same nonzero cktPrivateNet value to keep their traffic logically segregated from the general public network pool. For example, setting cktPrivateNet to 7 on a bank customer's circuits ensures they only draw bandwidth from and route through resources allocated to private network 7, rather than competing with the general public customer base for capacity.