Nyquist C4000 Series System Software - Concurrent Call License Expansion Pack. All C4000 system bundles include licensing for ten (10) concurrent calls. This license expansion pack increases the Concurrent Call License (CCL) limit of any system by 10 calls, allowing the concurrent call handling capacity of any size system to be expanded in 10-call increments (e.g., If a system’s current CCL limit is 10 calls, installing this expansion license will increase it by 10 to 20 concurrent calls).