Call Flows This section describes the key call flows for this feature. URR Installation on Initial Attach Call FlowSGW CDR Call FlowURR Removal and CDR Reporting on Detach Call FlowUsage Report on Hitting Threshold Call FlowURR Installation for Dedicated Bearer Call FlowURR Removal and CDR Generation on Deletion of Dedicated Bearer Call FlowVolume Reporting on S11 Trigger Call FlowVolume Reporting on S5 Trigger Call Flow