5.11 PDN GW initiated IPv4 address Delete Procedure

23.4023GPPArchitecture enhancements for non-3GPP accessesRelease 18TS

This procedure is initiated by the PDN GW when the UE releases the IPv4 address using DHCPv4 procedure or the lease for the IP address has expired. The procedure is used to delete the IPv4 address from the PDN connection context.

Figure 5.11-1: PDN GW initiated IPv4 address Delete Procedure

This procedure applies to the Non-Roaming (Figure 4.2.1-1), Roaming (Figure 4.2.1-2) and Local Breakout (Figure 4.2.3-4) cases. For the Roaming and Local Breakout cases, the vPCRF forwards messages between the Serving GW and the hPCRF. In the Local Breakout case, the vPCRF forwards messages between the PDN GW and the hPCRF.

The optional interaction steps between the gateways and the PCRF in the procedures in figure 5.11-1 only occur if dynamic policy provisioning is deployed. Otherwise policy may be statically configured with the gateway.

1. The PCEF initiates the Gateway Control Session Modification Procedure with the PCRF as specified in TS 23.203 [19]. The PDN GW provides the information to enable the PCRF to uniquely identify the IP CAN session.

2. In case QoS rules have to be modified, e.g. change of SDF filters, the PCRF initiates a GW Control and QoS rules provision procedure as described in TS 23.203 [19] to inform the S‑GW of the updated QoS rules.

3. The S‑GW initiates the "PDN GW initiated bearer modification without QoS update" as described in TS 23.401 [4], clause 5.4.3, between steps (A) and (B).

4. The S‑GW informs the PCRF of the success of the QoS rules enforcement, thus ending the GW Control and QoS rules provision procedure described in TS 23.203 [19].

5. The PDN GW sends a Binding Revocation Indication (PDN address) message to the Serving GW to revoke the IPv4 address.

6. The Serving GW returns a Binding Revocation Acknowledgement message to the PDN GW.