Cisco ASR 5000 Administration Manual page 118

▀ Features and Terminology
Credit Control Request
Credit Control Request (CCR) is the message that is sent from the client to the server to request quota and authorization.
CCR is sent before the establishment of MIP session, and at the termination of the MIP session. It can be sent during
service delivery to request more quotas.
 Credit Control Request - Initial (CCR-I)
 Credit Control Request - Update (CCR-U)
 Credit Control Request - Terminate (CCR-T)
 Credit Control Answer (CCA)
 Credit Control Answer - Initial (CCA-I)
 Credit Control Answer - Update (CCA-U)
If the MSCC AVP is missing in CCA-Update it is treated as invalid CCA and the session is terminated.
 Credit Control Answer - Terminate (CCA-T)
The following figure depicts the call flow for a simple call request in the GGSN/P-GW/IPSG Gy implementation.
▄ Cisco ASR 5000 IP Services Gateway Administration Guide
118
Gy Interface Support
OL-27210-02