Oversubscription is based on the capabilities of the ATM line module on which the dynamic interface is configured. For details about the capabilities of specific ATM line modules, see either Module Capabilities in Configuring ATM , or the Link Layer Maximums tables in JUNOSe Release Notes, Appendix A, System Maximums.
Each ATM line module supports a maximum number of configured subinterfaces or VCs, and a smaller maximum number of subinterfaces or VCs that can be active at any one time. The maximum number of active subinterfaces or VCs determines the number of subscribers that can connect to the router through this line module at any one time.
As a result, you can oversubscribe static ATM 1483 subinterfaces or bulk-configured VC ranges by creating up to the maximum number of configured subinterfaces or VCs supported on the module, knowing that no more than the maximum number of active subinterfaces or VCs can be connected to the router at any one time.