In Online Charging, which Request Type is used and in Offline also?

Interview
1

Q. In Online Charging, which Request Type is used and in Offline also?

a) CCR in Online and ACR in Offline
b) CCR in Online and AAA in Offline
c) CCR in Offline and ACR in Online
d) CCR in Offline and AAR in Online

Check 🔎

:arrow_right: Correct answer: Letter a.

In IMS Charging architecture, the Diameter Credit-Control-Request (CCR) is used for Online Charging, while the Accounting-Request (ACR) is used for Offline Charging.

  • Online Charging (OCS) → CCR/CCA messages over the Ro interface.
  • Offline Charging (CDF) → ACR/ACA messages over the Rf interface.
  • They serve different purposes: CCR for real-time credit control, ACR for event-based accounting.

Q. In Online Charging, which Request Type is used and in Offline also?

a) :white_check_mark: CCR in Online and ACR in Offline
→ Correct. This is the standard setup for IMS Charging models.

b) :x: CCR in Online and AAA in Offline
→ Incorrect. AAA is not a Diameter message type—it’s a general term (Authentication, Authorization, Accounting).

c) :x: CCR in Offline and ACR in Online
→ Incorrect. Roles are reversed.

d) :x: CCR in Offline and AAR in Online
→ Incorrect. AAR is used in Rx interface for resource authorization, not charging.