6.12 PDN GW initiated Resource Allocation Deactivation
23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS
6.12.1 PDN GW initiated Resource Allocation Deactivation with S2a PMIP
This procedure is performed to release all the resources associated with the PDN address, for example, due to IP‑CAN session modification requests from the PCRF or due to handover from Non-3GPP to 3GPP. When it is performed for an handover, the connections associated with the PDN address are released, but the PDN address is kept in the PDN GW.
Figure 6.12.1-1: PDN GW Initiated Binding Revocation with S2a PMIP
This procedure applies to the Non-Roaming (Figure 4.2.2-1), Roaming (Figure 4.2.3-1) and Local Breakout (Figure 4.2.3-4) cases. For the Roaming and Local Breakout cases, the vPCRF forwards messages between the non-3GPP IP access and the hPCRF. In the Local Breakout case, the vPCRF forwards messages between the PDN GW and the hPCRF. In the non-roaming case, the vPCRF is not involved at all.
The optional interaction steps between the gateways and the PCRF in the procedures in figure 6.12.1-1 only occur if dynamic policy provisioning is deployed. Otherwise policy may be statically configured with the gateway.
1. If dynamic PCC is deployed, the PDN GW initiated Resource Allocation Deactivation procedure may for example be triggered due to ‘IP CAN session Modification procedure’, as defined in TS 23.203 [19]. In this case, the resources associated with the PDN connection in the PDN GW are released.
The PDN GW initiated Resource Allocation Deactivation can also be triggered during handovers from Non-3GPP to 3GPP.
2. The PDN GW sends a Binding Revocation Indication message to the trusted non-3GPP IP access.
3. The resources may be released in the trusted non-3GPP IP access, according to an access specific, trusted non-3GPP IP access initiated, release mechanism.
4. If the resources are released in the trusted non-3GPP IP access, the trusted non-3GPP IP access initiates a Gateway Control Session Termination Procedure with the PCRF as specified in TS 23.203 [19].
5. The trusted non-3GPP IP access returns a Binding Revocation Acknowledgement message to the PDN GW.
6. In the case where the resources corresponding to the PDN connection are released in PDN GW, the PDN GW informs the 3GPP AAA Server of the PDN disconnection. If the UE no longer has any context in the 3GPP AAA Server, the 3GPP AAA Server notifies the HSS as described in clause 12.1.2.
NOTE: For some accesses, the resources may be released independently of deactivation from the PDN GW.
6.12.2 PDN GW initiated Resource Allocation Deactivation with S2a MIPv4
This procedure is performed to release all resource allocations associated with the PDN address, for example, due to IP‑CAN session modification requests from the PCRF or due to handover without optimization from Non-3GPP to 3GPP. When it is performed for an handover, the connections associated with the PDN address are released, but the PDN address is kept in the PDN GW.
Figure 6.12.2-1: PDN GW Initiated Registration Revocation over S2a MIPv4 interface
This procedure applies to the Non-Roaming (Figure 4.2.2-1), Roaming (Figure 4.2.3-1) and Local Breakout (Figure 4.2.3-4) cases. For the Roaming and Local Breakout cases, the vPCRF forwards messages between the non-3GPP access and the hPCRF. In the Local Breakout case, the vPCRF forwards messages between the PDN GW and the hPCRF. In the non-roaming case, the vPCRF is not involved at all.
The optional interaction steps between the gateways and the PCRF in the procedures in figure 6.12.2-1 only occur if dynamic policy provisioning is deployed. Otherwise policy may be statically configured with the gateway.
1. If dynamic PCC is deployed, the PDN GW initiated Resource Allocation Deactivation procedure may for example be triggered due to ‘IP CAN session Modification procedure’ as defined in TS 23.203 [19]. In this case the resources associated with the PDN connection in the PDN GW are released.
The PDN GW initiated Resource Allocation Deactivation can also be triggered during handovers from Non-3GPP to 3GPP.
2. If the revocation support has been negotiated, the PDN GW sends a Registration Revocation message to the trusted non-3GPP IP access as defined in RFC 3543 [25].
3. The resources may be released in the trusted non-3GPP IP access, according to an access specific, trusted non-3GPP IP access initiated, release mechanism.
4. The Trusted Non-3GPP Access Network detects the UE’s leaving and initiates a Gateway Control Session Termination Procedure with the PCRF as specified in TS 23.203 [19]. The Trusted Non-3GPP Access Network no longer applies QoS policy to service data flows for this UE.
5. The trusted non-3GPP IP access returns a Registration Revocation Acknowledgement message to the PDN GW.
6. In the case where the resources corresponding to the PDN connection are released in PDN GW, the PDN GW informs the 3GPP AAA Server of the PDN disconnection. If the UE no longer has any context in the 3GPP AAA Server, the 3GPP AAA Server notifies the HSS as described in clause 12.1.2.
NOTE: For some accesses, the resources may be released independently of deactivation from the PDN GW.
6.12.3 PDN GW initiated Resource Allocation Deactivation for Chained PMIP-based S8-S2a Roaming
This clause defines the PDN GW initiated resource allocation deactivation for chained PMIP-based S8-S2a roaming. This procedure also applies for PMIP-based S8-S2b chaining.
Figure 6.12.3-1: PDN GW Initiated Binding Revocation for Chained PMIP-based S8-S2a Roaming Case
The optional interaction step between the gateways and the PCRF in the procedures in figure 6.12.3-1 occur only if dynamic policy provisioning is deployed. Otherwise policies may be statically configured in the gateway.
1. The PDN GW sends a Binding Revocation Indication message to the MAG function in the Serving GW.
2. The Serving GW sends a corresponding Binding Revocation Indication message to the MAG function of the trusted non-3GPP IP access or ePDG.
3. The trusted non-3GPP IP access or ePDG may release allocated resources in the non-3GPP IP access according to access specific release mechanisms.
4. In case a Gateway Control Session between the trusted non-3GPP access or ePDG and hPCRF exists, the Gateway Control Session Termination procedure, as specified in TS 23.203 [19], is performed.
5. The MAG function of the trusted non-3GPP IP access or ePDG returns a Binding Revocation Acknowledgement message to the Serving GW.
6. The MAG function of the Serving GW or ePDG sends a corresponding Binding Revocation Acknowledgement message to the PDN GW.
7. In the case where the resources corresponding to the PDN connection are released in the PDN GW, the PDN GW informs the 3GPP AAA Server of the PDN disconnection. If the UE no longer has any context in the 3GPP AAA Server, the 3GPP AAA Server notifies the HSS as described in clause 12.1.2.
NOTE: For some accesses, the resources may be released independently of deactivation from the PDN GW.