An Event ACR is generated according to the tables that describe the AVPs present in the OCSBC’s ACR message. Refer to the checked items in the Event column to see all included AVPs. Note that the Accounting-Record-Type AVP (480) is set to Event_Record (1).

The Event-Type AVP (AVP code 823) is a Grouped AVP and contains information about the type of chargeable telecommunication service/event for which the accounting-request and/or credit control request message(s) is generated.

It is used in an AAR Event record. In this context, refer to the following:

The OCSBC generates additional information for SMS and distributes the information within the SIP-Method grouped AVP.

When any of the following responses are received in response to a SIP Invite, an Event ACR message is created to indicate there has been an unsuccessful session attempt:

• 4xx Request Failure Code — this code is used when the SIP transaction is terminated due to an IMS node receiving a 4xx error response.
• 5xx Server Failure Code — this code is used when the SIP transaction is terminated due to an IMS node receiving a 5xx error response.
• 6xx Global Failure Code — this code is used when the SIP transaction is terminated due to an IMS node receiving a 6xx error response.

This example call flow shows how a 5xx server failure results in the sending of an Event ACR.

Call Flow Example Showing Event ACR Generation Due to 5xx Server Failure

The following call flow example shows two session agents. The first session agent replies with 503, which results in an Event ACR with cause code 503. The second session agent replies with 200OK that causes the sending of a Start ACR. The generate-start parameter is OK.

Call Flow Example Showing Sending of an Event and Start ACR

This example call flow illustrates the same call flow when generate-start are equal to Invite. In this case, Start, Interim and Stop ACRs are sent. The generate-start parameter is OK.

Call Flow Example Showing Generation of Event ACRs Due to 5xx Server Failures

This example call flow shows how a session is created and a Start ACR is sent but then a 5xx server failure occurs that results in sending an Interim ACR. The generate-start parameter is Invite.

Call Flow Example Showing Sending of Start and Interim ACRs

This example call flow shows how the SD rejects a call before a session is created. When the enhanced-cdr option is not set, an Event ACR is then sent.

Call Flow Example Showing Unsuccessful Session Creation and Sending of a Event ACR

An Event ACR is issued when the following SIP messages are received:

• 200 OK message for a SIP Register from the IMS core.
• SIP Final/Redirection Response 3xx
• SIP Final Response (4xx, 5xx or 6xx) — this indicates an unsuccessful session-unrelated procedure.
• SIP Final Response (4xx, 5xx or 6xx) — this indicates an unsuccessful SIP session set-up.

This example call flow shows an Event ACR that is created due to the reception of a 3xx SIP message. In this example the call fails after being redirected.

Event ACR Created Upon Reception of a 3xx Message Followed by Call Failure After Redirect

This example call flow shows an Event ACR that is created due to the reception of a 3xx SIP message. Then it shows a Start ACR upon reception of a 200OK. In this example the call succeeds after being redirected. The generate-start is OK.

Event ACR Created Upon Reception of a 3xx Message Followed by Call Success After Redirect

This example call flow shows a Start ACR being sent when an Invite is received and an Interim ACR that is created due to the reception of a 3xx SIP message. In this example the call succeeds after being redirected. The generate-start is Invite.

The OCSBC generates call data event records with information for SMS that differs somewhat from that of calls. You configure the OCSBC to generate ACRs for SMS using the same procedures you use for calls, which then treats the SMS messages as events, similar to call data during registrations.

End stations send SMS messages using a SIP MESSAGE (content-type=application/vnd.3gpp.sms) with a GSM-SMS body. The OCSBC complies with 3GPP specifications 23.040 (Technical realization of the Short Message Service (SMS) and 24.011 Point-to-Point (PP) Short Message Service (SMS) support on mobile radio interface) with respect to message format. The OCSBC parses message information for AVP data during message processing and ultimately provides ACRs to the CCF using the Rf interface.

SMS processing that includes ACR generation includes a separate timer, the sms-report-timeout within the sip-config, for SMS accounting. If the OCSBC does not receive a delivery report /submit report within this timer's value, it discards all accounting for that message. The diagrams below present the start and stop locations of this timer within the context of overall ACR generation.

The call flow diagram below illustrates the OCSBC, as P-CSCF, gathering data for the SMS report during a message originating scenario. The OCSBC ultimately issues the ACR after the message delivery is complete.

The call flow diagram below illustrates the OCSBC, as P-CSCF, gathering data for the SMS report during a message terminating scenario.

This feature also creates an Event CSV file when the generate-event parameter is enabled. The following table describes the inclusive CSV element order:

The OCSBC generates a different CSV for message events, triggered by SMS traffic. This layout is presented in Appendix B.