4.6 Application Detection and Enforcement Procedures

29.2133GPPPolicy and charging control signalling flows and Quality of Service (QoS) parameter mappingRelease 17TS

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4.6.1 TDF Session Establishment in case of solicited reporting

In the following procedure, the PCRF is the H-PCRF for the roaming UE with home routed access and the V-PCRF for the roaming UE with visited access.

As part of the IP-CAN Session Establishment or Modification procedure, in case of solicited application reporting with a TDF, the PCRF initiates a TDF Session Establishment with the selected TDF. The TDF is selected based on data received from the PCEF or a local configuration at the PCRF.

Figure 4.6.1.1: TDF Session Establishment in case of solicited reporting

1. PCRF initiates a session towards the TDF. The PCRF provisions the applicable ADC Rules for the corresponding TDF session by sending a Diameter TS-Request to the TDF, including user identity information, the UE Ipv4 address and/or UE Ipv6 prefix and, if available, PDN identifier, IP-CAN type, RAT type and additional parameters as defined in clause 4b.5.1.1 of 3GPP TS 29.212 [9]. PCRF may also subscribe to the Event Triggers (e.g. APPLICATION_START and APPLICATION_STOP).

NOTE: For PDN type Ipv4v6, in case the UE Ipv4 address is not available in the PCRF, the PCRF initiates the TDF session establishment providing the UE Ipv6 prefix, and will subsequently provide UE Ipv4 address to the TDF using Event-Report-Indication AVP to the TDF.

1a. This step applies to the IP-CAN Session Establishment procedure. If online charging is applicable for the TDF, and at least one ADC rule with charging parameters was activated, then the TDF requests credit information from the OCS over the Gyn interface. If the TDF receives credit re-authorisation triggers from the OCS then it requests the PCRF via a TSA message to provision the triggers at the PCEF and/or BBERF. The triggers to be provisioned are specified in the Event-Report-Indication AVP in the TSA message.

2. The TDF acknowledges the session establishment by sending a Diameter TS-Answer. The TDF may include Event-Report-Indication in the response.

4.6.1A TDF Session Establishment in case of unsolicited reporting

In the following procedure, the PCRF is the H-PCRF for the roaming UE with home routed access and the V-PCRF for the roaming UE with visited access.

When the TDF detects for an Ipv4 address or Ipv6 address the first application start, the TDF shall initiate the TDF Session Establishment procedure with the PCRF.

Figure 4.6.1A.1: TDF Session Establishment in case of unsolicited reporting

1. The TDF initiates a session by sending a CCR to the PCRF using the CC-Request-Type AVP set to the value INITIAL_REQUEST. The TDF provides the full UE IP address using either Framed-IP-Address AVP or Framed-Ipv6-Prefix AVP and, if available, the PDN identifier. The TDF also includes the TDF-Application-Identifier AVP, the Flow-Information AVP of the detected application when service data flow descriptions are deducible, within the Application-Detection-Information AVP and sets the event trigger value with APPLICATION_START. If Flow-Information AVP is included, the TDF-Application-Instance-Identifier shall also be included within the Application-Detection-Information AVP in order to allow correlation of APPLICATION_START.

2 The PCRF stores the information and acknowledges the session establishment by sending a CCA. The PCRF may include the Ipv6 prefix within the Framed-Ipv6-Prefix AVP if the established TDF session is Ipv6 address related.

NOTE 1: The TDF handles each Ipv4 address and Ipv6 prefix within a separate TDF session.

NOTE 2: In the scenario where the TDF performs initial Application Detection on vailabi simultaneous traffic flows for the same Ipv6 prefix (i.e. two or more from Ipv6 addresses of the same IP-CAN session) the TDF could not be aware that those flows belong to the same IP-CAN session until a response is received from the PCRF, containing the Ipv6 prefix. This leads to using separate TDF sessions for the Ipv6 addresses for the same IP-CAN session. The TDF reports new application detection information related to that Ipv6 prefix via any of the TDF sessions at a later stage.

4.6.2 TDF Session termination

In the following procedures, the PCRF is the H-PCRF for the roaming UE with home routed access and the V-PCRF for the roaming UE with visited access.

This procedure applies in any of the following cases:

– the corresponding IP-CAN session is terminated;

– the Ipv4 address of a dual stack IP-CAN session is released and there is an active Ipv4 address related TDF session for the IP-CAN session (only for unsolicited application reporting);

– at any point of time when the PCRF decides that the session with TDF is to be terminated (e.g. subscriber profile changes).

Figure 4.6.2.1: TDF Session Termination

1. The PCRF sends a RAR including the Session-Release-Cause AVP to request that the TDF terminates the TDF session.

2. For the solicited application reporting, the TDF removes/deactivates all the ADC Rules which are applied to the TDF session.

3. The TDF sends a RAA to acknowledge the RAR.

4. The TDF sends a CCR to the PCRF, indicating the TDF Session termination. The TDF requests the termination of the Sd session using the CC-Request-Type AVP set to the value TERMINATION_REQUEST. For solicited application reporting, if the usage monitoring is enabled, the TDF informs the PCRF about the resources that have been consumed by the user since the last report in the same request.

5. The PCRF acknowledges the TDF session termination by sending a CCA to the TDF.

4.6.3 TDF Session modification

4.6.3.1 Application Detection, Reporting and Control Rules Request

In the following procedure, the PCRF is the H-PCRF for the roaming UE with home routed access and the V-PCRF for the roaming UE with visited access.

Figure 4.6.3.1.1 Application Detection, Reporting and Control Rules Request

1. TDF is triggered to report an event(s) (e.g. The TDF detects the start/stop of an application traffic that matches with one or more activated ADC rules that do not contain the Mute-Notification AVP) for a TDF session. For the start of traffic detection, in case the enforcement actions were provided as a part of ADC rules, the TDF enforces corresponding actions for solicited application reporting.

2. The TDF sends a Diameter CCR to the PCRF with the CC-Request-Type AVP set to the value UPDATE_REQUEST to report an event. For the start of traffic detection, if PCRF has previously subscribed to the APPLICATION_START/APPLICATION_STOP Event-Triggers, the TDF includes TDF-Application-Identifier AVP, the Flow-Information AVP of the detected application when service data flow descriptions are deducible, within the Application-Detection-Information AVP and sets the event trigger value with APPLICATION_START. If Flow-Information AVP is included, the TDF-Application-Instance-Identifier shall also be included within the Application-Detection-Information AVP in order to allow correlation of APPLICATION_START. For the stop of traffic detection, if PCRF has previously subscribed to the APPLICATION_START/APPLICATION_STOP Event-Triggers, the TDF includes TDF-Application-Identifier AVP, the TDF-Application-Instance-Identifier AVP, if provided in the report of the start of application traffic detection within the Application-Detection-Information AVP and sets the event trigger value with APPLICATION_STOP. For the solicited application reporting, if usage monitoring is enabled and the usage threshold is reached or the PCRF removes the last ADC rule applicable for certain monitoring key or disables usage monitoring or requests usage report, the TDF may inform the PCRF about the corresponding usage that have been consumed by the user since the last report.

3. The PCRF stores the information, received in the Diameter CCR and makes the PCC/QoS and – in the solicited reporting case – ADC decisions.

4. The PCRF acknowledges to the TDF by sending a Diameter CCA. For the solicited application reporting, the PCRF may provide a new ADC decisions by including the ADC-Rule-Install AVP and/or ADC-Rule-Remove AVP to the TDF within this acknowledge.

5. For the solicited application reporting, the TDF installs, modifies and removes the ADC rules according the new ADC decisions provided in step 4.

NOTE: If the installation or modification of one or more ADC rules fails, the TDF reports the failure to the PCRF as defined in clause 4b.5.5 of 3GPP TS 29.212 [9].

4.6.3.2 Application Detection and Control Rules Provision

In the following procedure, the PCRF is the H-PCRF for the roaming UE with home routed access and the V-PCRF for the roaming UE with visited access. This procedure is applicable only for the solicited application reporting.

Figure 4.6.3.2.1 Application Detection and Control Rules Provision

1. The PCRF receives an internal or external trigger (e.g. the subscriber’s profile configuration is changed) to update the ADC rule or notify the event occurred at the PCEF/BBERF for a TDF session.

2. The PCRF sends a Diameter RAR to provide a new ADC decision by including the ADC-Rule-Install AVP and/or ADC-Rule-Remove AVP or notify the event occurred at the PCEF/BBERF by including the Event-Report-Indication AVP.

3. The TDF stores the information, received in the Diameter RAR. The TDF installs, modifies and removes the ADC rules according the new ADC decisions provided in step 2.

4. The TDF acknowledges to the PCRF by sending a Diameter RAA to inform the PCRF about the outcome of the actions related to the decision(s).