ATM can give customers with virtual circuits that seem traditional leased digital circuits. Such permanent virtual circuits (PVC) fixed as the customer pay the periodic fee for its use. The forwarding tables are naturally restored after power of equipment failure. The forwarding table entries for such fixed VC's are statically managed, the ideas used by Telco's for this is provisioning.
Provisioning needs two steps:
1. To calculate a complete path.
2. To select appropriate VPI/VCI for every step in the path, and manage each adjacent pair of switches.